import os
import sys
from contextlib import ExitStack
from fnmatch import fnmatch
from functools import partial
from tempfile import TemporaryDirectory

import click
from .. import _yaml
from ..types import _KeyStrength
from .._exceptions import BstError, LoadError, AppError
from .._versions import BST_FORMAT_VERSION
from .complete import main_bashcomplete, complete_path, CompleteUnhandled


##################################################################
#            Override of click's main entry point                #
##################################################################

# search_command()
#
# Helper function to get a command and context object
# for a given command.
#
# Args:
#    commands (list): A list of command words following `bst` invocation
#    context (click.Context): An existing toplevel context, or None
#
# Returns:
#    context (click.Context): The context of the associated command, or None
#
def search_command(args, *, context=None):
    if context is None:
        context = cli.make_context('bst', args, resilient_parsing=True)

    # Loop into the deepest command
    command = cli
    command_ctx = context
    for cmd in args:
        command = command_ctx.command.get_command(command_ctx, cmd)
        if command is None:
            return None
        command_ctx = command.make_context(command.name, [command.name],
                                           parent=command_ctx,
                                           resilient_parsing=True)

    return command_ctx


# Completion for completing command names as help arguments
def complete_commands(cmd, args, incomplete):
    command_ctx = search_command(args[1:])
    if command_ctx and command_ctx.command and isinstance(command_ctx.command, click.MultiCommand):
        return [subcommand + " " for subcommand in command_ctx.command.list_commands(command_ctx)
                if not command_ctx.command.get_command(command_ctx, subcommand).hidden]

    return []


# Special completion for completing the bst elements in a project dir
def complete_target(args, incomplete):
    """
    :param args: full list of args typed before the incomplete arg
    :param incomplete: the incomplete text to autocomplete
    :return: all the possible user-specified completions for the param
    """

    from .. import utils
    project_conf = 'project.conf'

    # First resolve the directory, in case there is an
    # active --directory/-C option
    #
    base_directory = '.'
    idx = -1
    try:
        idx = args.index('-C')
    except ValueError:
        try:
            idx = args.index('--directory')
        except ValueError:
            pass

    if idx >= 0 and len(args) > idx + 1:
        base_directory = args[idx + 1]
    else:
        # Check if this directory or any of its parent directories
        # contain a project config file
        base_directory, _ = utils._search_upward_for_files(base_directory, [project_conf])

    # Now parse the project.conf just to find the element path,
    # this is unfortunately a bit heavy.
    project_file = os.path.join(base_directory, project_conf)
    try:
        project = _yaml.load(project_file)
    except LoadError:
        # If there is no project directory in context, just dont
        # even bother trying to complete anything.
        return []

    # The project is not required to have an element-path
    element_directory = project.get('element-path')

    # If a project was loaded, use its element-path to
    # adjust our completion's base directory
    if element_directory:
        base_directory = os.path.join(base_directory, element_directory)

    complete_list = []
    for p in complete_path("File", incomplete, base_directory=base_directory):
        if p.endswith(".bst ") or p.endswith("/"):
            complete_list.append(p)
    return complete_list


def complete_artifact(orig_args, args, incomplete):
    from .._context import Context
    ctx = Context()

    config = None
    if orig_args:
        for i, arg in enumerate(orig_args):
            if arg in ('-c', '--config'):
                try:
                    config = orig_args[i + 1]
                except IndexError:
                    pass
    if args:
        for i, arg in enumerate(args):
            if arg in ('-c', '--config'):
                try:
                    config = args[i + 1]
                except IndexError:
                    pass
    ctx.load(config)

    # element targets are valid artifact names
    complete_list = complete_target(args, incomplete)
    complete_list.extend(ref for ref in ctx.artifactcache.cas.list_refs() if ref.startswith(incomplete))

    return complete_list


def override_completions(orig_args, cmd, cmd_param, args, incomplete):
    """
    :param orig_args: original, non-completion args
    :param cmd_param: command definition
    :param args: full list of args typed before the incomplete arg
    :param incomplete: the incomplete text to autocomplete
    :return: all the possible user-specified completions for the param
    """

    if cmd.name == 'help':
        return complete_commands(cmd, args, incomplete)

    # We can't easily extend click's data structures without
    # modifying click itself, so just do some weak special casing
    # right here and select which parameters we want to handle specially.
    if isinstance(cmd_param.type, click.Path):
        if (cmd_param.name == 'elements' or
                cmd_param.name == 'element' or
                cmd_param.name == 'except_' or
                cmd_param.opts == ['--track'] or
                cmd_param.opts == ['--track-except']):
            return complete_target(args, incomplete)
        if cmd_param.name == 'artifacts':
            return complete_artifact(orig_args, args, incomplete)

    raise CompleteUnhandled()


def override_main(self, args=None, prog_name=None, complete_var=None,
                  standalone_mode=True, **extra):

    # Hook for the Bash completion.  This only activates if the Bash
    # completion is actually enabled, otherwise this is quite a fast
    # noop.
    if main_bashcomplete(self, prog_name, partial(override_completions, args)):

        # If we're running tests we cant just go calling exit()
        # from the main process.
        #
        # The below is a quicker exit path for the sake
        # of making completions respond faster.
        if 'BST_TEST_SUITE' not in os.environ:
            sys.stdout.flush()
            sys.stderr.flush()
            os._exit(0)

        # Regular client return for test cases
        return

    original_main(self, args=args, prog_name=prog_name, complete_var=None,
                  standalone_mode=standalone_mode, **extra)


original_main = click.BaseCommand.main
click.BaseCommand.main = override_main


##################################################################
#                          Main Options                          #
##################################################################
def print_version(ctx, param, value):
    if not value or ctx.resilient_parsing:
        return

    from .. import __version__
    click.echo(__version__)
    ctx.exit()


@click.group(context_settings=dict(help_option_names=['-h', '--help']))
@click.option('--version', is_flag=True, callback=print_version,
              expose_value=False, is_eager=True)
@click.option('--config', '-c',
              type=click.Path(exists=True, dir_okay=False, readable=True),
              help="Configuration file to use")
@click.option('--directory', '-C', default=os.getcwd(),
              type=click.Path(file_okay=False, readable=True),
              help="Project directory (default: current directory)")
@click.option('--on-error', default=None,
              type=click.Choice(['continue', 'quit', 'terminate']),
              help="What to do when an error is encountered")
@click.option('--fetchers', type=click.INT, default=None,
              help="Maximum simultaneous download tasks")
@click.option('--builders', type=click.INT, default=None,
              help="Maximum simultaneous build tasks")
@click.option('--pushers', type=click.INT, default=None,
              help="Maximum simultaneous upload tasks")
@click.option('--network-retries', type=click.INT, default=None,
              help="Maximum retries for network tasks")
@click.option('--no-interactive', is_flag=True, default=False,
              help="Force non interactive mode, otherwise this is automatically decided")
@click.option('--verbose/--no-verbose', default=None,
              help="Be extra verbose")
@click.option('--debug/--no-debug', default=None,
              help="Print debugging output")
@click.option('--error-lines', type=click.INT, default=None,
              help="Maximum number of lines to show from a task log")
@click.option('--message-lines', type=click.INT, default=None,
              help="Maximum number of lines to show in a detailed message")
@click.option('--log-file',
              type=click.File(mode='w', encoding='UTF-8'),
              help="A file to store the main log (allows storing the main log while in interactive mode)")
@click.option('--colors/--no-colors', default=None,
              help="Force enable/disable ANSI color codes in output")
@click.option('--strict/--no-strict', default=None, is_flag=True,
              help="Elements must be rebuilt when their dependencies have changed")
@click.option('--option', '-o', type=click.Tuple([str, str]), multiple=True, metavar='OPTION VALUE',
              help="Specify a project option")
@click.option('--default-mirror', default=None,
              help="The mirror to fetch from first, before attempting other mirrors")
@click.option('--pull-buildtrees', is_flag=True, default=None,
              help="Include an element's build tree when pulling remote element artifacts")
@click.pass_context
def cli(context, **kwargs):
    """Build and manipulate BuildStream projects

    Most of the main options override options in the
    user preferences configuration file.
    """

    from .app import App

    # Create the App, giving it the main arguments
    context.obj = App.create(dict(kwargs))
    context.call_on_close(context.obj.cleanup)


##################################################################
#                           Help Command                         #
##################################################################
@cli.command(name="help", short_help="Print usage information",
             context_settings={"help_option_names": []})
@click.argument("command", nargs=-1, metavar='COMMAND')
@click.pass_context
def help_command(ctx, command):
    """Print usage information about a given command
    """
    command_ctx = search_command(command, context=ctx.parent)
    if not command_ctx:
        click.echo("Not a valid command: '{} {}'"
                   .format(ctx.parent.info_name, " ".join(command)), err=True)
        sys.exit(-1)

    click.echo(command_ctx.command.get_help(command_ctx), err=True)

    # Hint about available sub commands
    if isinstance(command_ctx.command, click.MultiCommand):
        detail = " "
        if command:
            detail = " {} ".format(" ".join(command))
        click.echo("\nFor usage on a specific command: {} help{}COMMAND"
                   .format(ctx.parent.info_name, detail), err=True)


##################################################################
#                           Init Command                         #
##################################################################
@cli.command(short_help="Initialize a new BuildStream project")
@click.option('--project-name', type=click.STRING,
              help="The project name to use")
@click.option('--format-version', type=click.INT, default=BST_FORMAT_VERSION,
              help="The required format version (default: {})".format(BST_FORMAT_VERSION))
@click.option('--element-path', type=click.Path(), default="elements",
              help="The subdirectory to store elements in (default: elements)")
@click.option('--force', '-f', default=False, is_flag=True,
              help="Allow overwriting an existing project.conf")
@click.pass_obj
def init(app, project_name, format_version, element_path, force):
    """Initialize a new BuildStream project

    Creates a new BuildStream project.conf in the project
    directory.

    Unless `--project-name` is specified, this will be an
    interactive session.
    """
    app.init_project(project_name, format_version, element_path, force)


##################################################################
#                          Build Command                         #
##################################################################
@cli.command(short_help="Build elements in a pipeline")
@click.option('--all', 'all_', default=False, is_flag=True,
              help="Build elements that would not be needed for the current build plan")
@click.option('--track', 'track_', multiple=True,
              type=click.Path(readable=False),
              help="Specify elements to track during the build. Can be used "
                   "repeatedly to specify multiple elements")
@click.option('--track-all', default=False, is_flag=True,
              help="Track all elements in the pipeline")
@click.option('--track-except', multiple=True,
              type=click.Path(readable=False),
              help="Except certain dependencies from tracking")
@click.option('--track-cross-junctions', '-J', default=False, is_flag=True,
              help="Allow tracking to cross junction boundaries")
@click.option('--track-save', default=False, is_flag=True,
              help="Deprecated: This is ignored")
@click.argument('elements', nargs=-1,
                type=click.Path(readable=False))
@click.pass_obj
def build(app, elements, all_, track_, track_save, track_all, track_except, track_cross_junctions):
    """Build elements in a pipeline"""

    if (track_except or track_cross_junctions) and not (track_ or track_all):
        click.echo("ERROR: The --track-except and --track-cross-junctions options "
                   "can only be used with --track or --track-all", err=True)
        sys.exit(-1)

    if track_save:
        click.echo("WARNING: --track-save is deprecated, saving is now unconditional", err=True)

    with app.initialized(session_name="Build"):
        if not all_ and not elements:
            guessed_target = app.context.guess_element()
            if guessed_target:
                elements = (guessed_target,)

        if track_all:
            track_ = elements

        app.stream.build(elements,
                         track_targets=track_,
                         track_except=track_except,
                         track_cross_junctions=track_cross_junctions,
                         build_all=all_)


##################################################################
#                           Pull Command                         #
##################################################################
@cli.command(short_help="Pull a built artifact")
@click.option('--deps', '-d', default='none',
              type=click.Choice(['none', 'all']),
              help='The dependency artifacts to pull (default: none)')
@click.option('--remote', '-r',
              help="The URL of the remote cache (defaults to the first configured cache)")
@click.argument('elements', nargs=-1,
                type=click.Path(readable=False))
@click.pass_obj
def pull(app, elements, deps, remote):
    """Pull a built artifact from the configured remote artifact cache.

    By default the artifact will be pulled one of the configured caches
    if possible, following the usual priority order. If the `--remote` flag
    is given, only the specified cache will be queried.

    Specify `--deps` to control which artifacts to pull:

    \b
        none:  No dependencies, just the element itself
        all:   All dependencies
    """

    with app.initialized(session_name="Pull"):
        if not elements:
            guessed_target = app.context.guess_element()
            if guessed_target:
                elements = (guessed_target,)

        app.stream.pull(elements, selection=deps, remote=remote)


##################################################################
#                           Push Command                         #
##################################################################
@cli.command(short_help="Push a built artifact")
@click.option('--deps', '-d', default='none',
              type=click.Choice(['none', 'all']),
              help='The dependencies to push (default: none)')
@click.option('--remote', '-r', default=None,
              help="The URL of the remote cache (defaults to the first configured cache)")
@click.argument('elements', nargs=-1,
                type=click.Path(readable=False))
@click.pass_obj
def push(app, elements, deps, remote):
    """Push a built artifact to a remote artifact cache.

    The default destination is the highest priority configured cache. You can
    override this by passing a different cache URL with the `--remote` flag.

    If bst has been configured to include build trees on artifact pulls,
    an attempt will be made to pull any required build trees to avoid the
    skipping of partial artifacts being pushed.

    Specify `--deps` to control which artifacts to push:

    \b
        none:  No dependencies, just the element itself
        all:   All dependencies
    """
    with app.initialized(session_name="Push"):
        if not elements:
            guessed_target = app.context.guess_element()
            if guessed_target:
                elements = (guessed_target,)

        app.stream.push(elements, selection=deps, remote=remote)


##################################################################
#                           Show Command                         #
##################################################################
@cli.command(short_help="Show elements in the pipeline")
@click.option('--except', 'except_', multiple=True,
              type=click.Path(readable=False),
              help="Except certain dependencies")
@click.option('--deps', '-d', default='all',
              type=click.Choice(['none', 'plan', 'run', 'build', 'all']),
              help='The dependencies to show (default: all)')
@click.option('--order', default="stage",
              type=click.Choice(['stage', 'alpha']),
              help='Staging or alphabetic ordering of dependencies')
@click.option('--format', '-f', 'format_', metavar='FORMAT', default=None,
              type=click.STRING,
              help='Format string for each element')
@click.argument('elements', nargs=-1,
                type=click.Path(readable=False))
@click.pass_obj
def show(app, elements, deps, except_, order, format_):
    """Show elements in the pipeline

    By default this will show all of the dependencies of the
    specified target element.

    Specify `--deps` to control which elements to show:

    \b
        none:  No dependencies, just the element itself
        plan:  Dependencies required for a build plan
        run:   Runtime dependencies, including the element itself
        build: Build time dependencies, excluding the element itself
        all:   All dependencies

    \b
    FORMAT
    ~~~~~~
    The --format option controls what should be printed for each element,
    the following symbols can be used in the format string:

    \b
        %{name}           The element name
        %{key}            The abbreviated cache key (if all sources are consistent)
        %{full-key}       The full cache key (if all sources are consistent)
        %{state}          cached, buildable, waiting or inconsistent
        %{config}         The element configuration
        %{vars}           Variable configuration
        %{env}            Environment settings
        %{public}         Public domain data
        %{workspaced}     If the element is workspaced
        %{workspace-dirs} A list of workspace directories

    The value of the %{symbol} without the leading '%' character is understood
    as a pythonic formatting string, so python formatting features apply,
    examle:

    \b
        bst show target.bst --format \\
            'Name: %{name: ^20} Key: %{key: ^8} State: %{state}'

    If you want to use a newline in a format string in bash, use the '$' modifier:

    \b
        bst show target.bst --format \\
            $'---------- %{name} ----------\\n%{vars}'
    """
    with app.initialized():
        if not elements:
            guessed_target = app.context.guess_element()
            if guessed_target:
                elements = (guessed_target,)

        dependencies = app.stream.load_selection(elements,
                                                 selection=deps,
                                                 except_targets=except_)

        if order == "alpha":
            dependencies = sorted(dependencies)

        if not format_:
            format_ = app.context.log_element_format

        report = app.logger.show_pipeline(dependencies, format_)
        click.echo(report, color=app.colors)


##################################################################
#                          Shell Command                         #
##################################################################
@cli.command(short_help="Shell into an element's sandbox environment")
@click.option('--build', '-b', 'build_', is_flag=True, default=False,
              help='Stage dependencies and sources to build')
@click.option('--sysroot', '-s', default=None,
              type=click.Path(exists=True, file_okay=False, readable=True),
              help="An existing sysroot")
@click.option('--mount', type=click.Tuple([click.Path(exists=True), str]), multiple=True,
              metavar='HOSTPATH PATH',
              help="Mount a file or directory into the sandbox")
@click.option('--isolate', is_flag=True, default=False,
              help='Create an isolated build sandbox')
@click.option('--use-buildtree', '-t', 'cli_buildtree', type=click.Choice(['ask', 'try', 'always', 'never']),
              default='ask',
              help='Defaults to ask but if set to always the function will fail if a build tree is not available')
@click.argument('element', required=False,
                type=click.Path(readable=False))
@click.argument('command', type=click.STRING, nargs=-1)
@click.pass_obj
def shell(app, element, sysroot, mount, isolate, build_, cli_buildtree, command):
    """Run a command in the target element's sandbox environment

    This will stage a temporary sysroot for running the target
    element, assuming it has already been built and all required
    artifacts are in the local cache.

    Use the --build option to create a temporary sysroot for
    building the element instead.

    Use the --sysroot option with an existing failed build
    directory or with a checkout of the given target, in order
    to use a specific sysroot.

    If no COMMAND is specified, the default is to attempt
    to run an interactive shell.
    """
    from ..element import Scope
    from .._project import HostMount
    from .._pipeline import PipelineSelection

    if build_:
        scope = Scope.BUILD
    else:
        scope = Scope.RUN

    use_buildtree = False

    with app.initialized():
        if not element:
            element = app.context.guess_element()
            if not element:
                raise AppError('Missing argument "ELEMENT".')

        dependencies = app.stream.load_selection((element,), selection=PipelineSelection.NONE)
        element = dependencies[0]
        prompt = app.shell_prompt(element)
        mounts = [
            HostMount(path, host_path)
            for host_path, path in mount
        ]

        cached = element._cached_buildtree()
        if cli_buildtree == "always":
            if cached:
                use_buildtree = True
            else:
                raise AppError("No buildtree is cached but the use buildtree option was specified")
        elif cli_buildtree == "never":
            pass
        elif cli_buildtree == "try":
            use_buildtree = cached
        else:
            if app.interactive and cached:
                use_buildtree = bool(click.confirm('Do you want to use the cached buildtree?'))
        if use_buildtree and not element._cached_success():
            click.echo("Warning: using a buildtree from a failed build.")

        try:
            exitcode = app.stream.shell(element, scope, prompt,
                                        directory=sysroot,
                                        mounts=mounts,
                                        isolate=isolate,
                                        command=command,
                                        usebuildtree=use_buildtree)
        except BstError as e:
            raise AppError("Error launching shell: {}".format(e), detail=e.detail) from e

    # If there were no errors, we return the shell's exit code here.
    sys.exit(exitcode)


##################################################################
#                        Checkout Command                        #
##################################################################
@cli.command(short_help="Checkout a built artifact")
@click.option('--force', '-f', default=False, is_flag=True,
              help="Allow files to be overwritten")
@click.option('--deps', '-d', default='run',
              type=click.Choice(['run', 'build', 'none']),
              help='The dependencies to checkout (default: run)')
@click.option('--integrate/--no-integrate', default=True, is_flag=True,
              help="Whether to run integration commands")
@click.option('--hardlinks', default=False, is_flag=True,
              help="Checkout hardlinks instead of copies (handle with care)")
@click.option('--tar', default=False, is_flag=True,
              help="Create a tarball from the artifact contents instead "
                   "of a file tree. If LOCATION is '-', the tarball "
                   "will be dumped to the standard output.")
@click.argument('element', required=False,
                type=click.Path(readable=False))
@click.argument('location', type=click.Path(), required=False)
@click.pass_obj
def checkout(app, element, location, force, deps, integrate, hardlinks, tar):
    """Checkout a built artifact to the specified location
    """
    from ..element import Scope

    if not element and not location:
        click.echo("ERROR: LOCATION is not specified", err=True)
        sys.exit(-1)

    if element and not location:
        # Nasty hack to get around click's optional args
        location = element
        element = None

    if hardlinks and tar:
        click.echo("ERROR: options --hardlinks and --tar conflict", err=True)
        sys.exit(-1)

    if deps == "run":
        scope = Scope.RUN
    elif deps == "build":
        scope = Scope.BUILD
    elif deps == "none":
        scope = Scope.NONE

    with app.initialized():
        if not element:
            element = app.context.guess_element()
            if not element:
                raise AppError('Missing argument "ELEMENT".')

        app.stream.checkout(element,
                            location=location,
                            force=force,
                            scope=scope,
                            integrate=integrate,
                            hardlinks=hardlinks,
                            tar=tar)


##################################################################
#                        Source Command                          #
##################################################################
@cli.group(short_help="Manipulate sources for an element")
def source():
    """Manipulate sources for an element"""


##################################################################
#                     Source Fetch Command                       #
##################################################################
@source.command(name="fetch", short_help="Fetch sources in a pipeline")
@click.option('--except', 'except_', multiple=True,
              type=click.Path(readable=False),
              help="Except certain dependencies from fetching")
@click.option('--deps', '-d', default='plan',
              type=click.Choice(['none', 'plan', 'all']),
              help='The dependencies to fetch (default: plan)')
@click.option('--track', 'track_', default=False, is_flag=True,
              help="Track new source references before fetching")
@click.option('--track-cross-junctions', '-J', default=False, is_flag=True,
              help="Allow tracking to cross junction boundaries")
@click.argument('elements', nargs=-1,
                type=click.Path(readable=False))
@click.pass_obj
def source_fetch(app, elements, deps, track_, except_, track_cross_junctions):
    """Fetch sources required to build the pipeline

    By default this will only try to fetch sources which are
    required for the build plan of the specified target element,
    omitting sources for any elements which are already built
    and available in the artifact cache.

    Specify `--deps` to control which sources to fetch:

    \b
        none:  No dependencies, just the element itself
        plan:  Only dependencies required for the build plan
        all:   All dependencies
    """
    from .._pipeline import PipelineSelection

    if track_cross_junctions and not track_:
        click.echo("ERROR: The --track-cross-junctions option can only be used with --track", err=True)
        sys.exit(-1)

    if track_ and deps == PipelineSelection.PLAN:
        click.echo("WARNING: --track specified for tracking of a build plan\n\n"
                   "Since tracking modifies the build plan, all elements will be tracked.", err=True)
        deps = PipelineSelection.ALL

    with app.initialized(session_name="Fetch"):
        if not elements:
            guessed_target = app.context.guess_element()
            if guessed_target:
                elements = (guessed_target,)

        app.stream.fetch(elements,
                         selection=deps,
                         except_targets=except_,
                         track_targets=track_,
                         track_cross_junctions=track_cross_junctions)


##################################################################
#                     Source Track Command                       #
##################################################################
@source.command(name="track", short_help="Track new source references")
@click.option('--except', 'except_', multiple=True,
              type=click.Path(readable=False),
              help="Except certain dependencies from tracking")
@click.option('--deps', '-d', default='none',
              type=click.Choice(['none', 'all']),
              help='The dependencies to track (default: none)')
@click.option('--cross-junctions', '-J', default=False, is_flag=True,
              help="Allow crossing junction boundaries")
@click.argument('elements', nargs=-1,
                type=click.Path(readable=False))
@click.pass_obj
def source_track(app, elements, deps, except_, cross_junctions):
    """Consults the specified tracking branches for new versions available
    to build and updates the project with any newly available references.

    By default this will track just the specified element, but you can also
    update a whole tree of dependencies in one go.

    Specify `--deps` to control which sources to track:

    \b
        none:  No dependencies, just the specified elements
        all:   All dependencies of all specified elements
    """
    with app.initialized(session_name="Track"):
        if not elements:
            guessed_target = app.context.guess_element()
            if guessed_target:
                elements = (guessed_target,)

        # Substitute 'none' for 'redirect' so that element redirections
        # will be done
        if deps == 'none':
            deps = 'redirect'
        app.stream.track(elements,
                         selection=deps,
                         except_targets=except_,
                         cross_junctions=cross_junctions)


##################################################################
#                  Source Checkout Command                      #
##################################################################
@source.command(name='checkout', short_help='Checkout sources for an element')
@click.option('--force', '-f', default=False, is_flag=True,
              help="Allow files to be overwritten")
@click.option('--except', 'except_', multiple=True,
              type=click.Path(readable=False),
              help="Except certain dependencies")
@click.option('--deps', '-d', default='none',
              type=click.Choice(['build', 'none', 'run', 'all']),
              help='The dependencies whose sources to checkout (default: none)')
@click.option('--fetch', 'fetch_', default=False, is_flag=True,
              help='Fetch elements if they are not fetched')
@click.option('--tar', 'tar', default=False, is_flag=True,
              help='Create a tarball from the element\'s sources instead of a '
                   'file tree.')
@click.option('--include-build-scripts', 'build_scripts', is_flag=True)
@click.argument('element', required=False, type=click.Path(readable=False))
@click.argument('location', type=click.Path(), required=False)
@click.pass_obj
def source_checkout(app, element, location, force, deps, fetch_, except_,
                    tar, build_scripts):
    """Checkout sources of an element to the specified location
    """
    if not element and not location:
        click.echo("ERROR: LOCATION is not specified", err=True)
        sys.exit(-1)

    if element and not location:
        # Nasty hack to get around click's optional args
        location = element
        element = None

    with app.initialized():
        if not element:
            element = app.context.guess_element()
            if not element:
                raise AppError('Missing argument "ELEMENT".')

        app.stream.source_checkout(element,
                                   location=location,
                                   force=force,
                                   deps=deps,
                                   fetch=fetch_,
                                   except_targets=except_,
                                   tar=tar,
                                   include_build_scripts=build_scripts)


##################################################################
#                      Workspace Command                         #
##################################################################
@cli.group(short_help="Manipulate developer workspaces")
def workspace():
    """Manipulate developer workspaces"""


##################################################################
#                     Workspace Open Command                     #
##################################################################
@workspace.command(name='open', short_help="Open a new workspace")
@click.option('--no-checkout', default=False, is_flag=True,
              help="Do not checkout the source, only link to the given directory")
@click.option('--force', '-f', default=False, is_flag=True,
              help="The workspace will be created even if the directory in which it will be created is not empty " +
              "or if a workspace for that element already exists")
@click.option('--track', 'track_', default=False, is_flag=True,
              help="Track and fetch new source references before checking out the workspace")
@click.option('--directory', type=click.Path(file_okay=False), default=None,
              help="Only for use when a single Element is given: Set the directory to use to create the workspace")
@click.argument('elements', nargs=-1, type=click.Path(readable=False), required=True)
@click.pass_obj
def workspace_open(app, no_checkout, force, track_, directory, elements):
    """Open a workspace for manual source modification"""

    with app.initialized():
        app.stream.workspace_open(elements,
                                  no_checkout=no_checkout,
                                  track_first=track_,
                                  force=force,
                                  custom_dir=directory)


##################################################################
#                     Workspace Close Command                    #
##################################################################
@workspace.command(name='close', short_help="Close workspaces")
@click.option('--remove-dir', default=False, is_flag=True,
              help="Remove the path that contains the closed workspace")
@click.option('--all', '-a', 'all_', default=False, is_flag=True,
              help="Close all open workspaces")
@click.argument('elements', nargs=-1,
                type=click.Path(readable=False))
@click.pass_obj
def workspace_close(app, remove_dir, all_, elements):
    """Close a workspace"""

    with app.initialized():
        if not (all_ or elements):
            # NOTE: I may need to revisit this when implementing multiple projects
            # opening one workspace.
            element = app.context.guess_element()
            if element:
                elements = (element,)
            else:
                raise AppError('No elements specified')

        # Early exit if we specified `all` and there are no workspaces
        if all_ and not app.stream.workspace_exists():
            click.echo('No open workspaces to close', err=True)
            sys.exit(0)

        if all_:
            elements = [element_name for element_name, _ in app.context.get_workspaces().list()]

        elements = app.stream.redirect_element_names(elements)

        # Check that the workspaces in question exist, and that it's safe to
        # remove them.
        nonexisting = []
        for element_name in elements:
            if not app.stream.workspace_exists(element_name):
                nonexisting.append(element_name)
            if (app.stream.workspace_is_required(element_name) and app.interactive and
                    app.context.prompt_workspace_close_project_inaccessible):
                click.echo("Removing '{}' will prevent you from running "
                           "BuildStream commands from the current directory".format(element_name))
                if not click.confirm('Are you sure you want to close this workspace?'):
                    click.echo('Aborting', err=True)
                    sys.exit(-1)
        if nonexisting:
            raise AppError("Workspace does not exist", detail="\n".join(nonexisting))

        if app.interactive and remove_dir and app.context.prompt_workspace_close_remove_dir:
            if not click.confirm('This will remove all your changes, are you sure?'):
                click.echo('Aborting', err=True)
                sys.exit(-1)

        for element_name in elements:
            app.stream.workspace_close(element_name, remove_dir=remove_dir)


##################################################################
#                     Workspace Reset Command                    #
##################################################################
@workspace.command(name='reset', short_help="Reset a workspace to its original state")
@click.option('--soft', default=False, is_flag=True,
              help="Reset workspace state without affecting its contents")
@click.option('--track', 'track_', default=False, is_flag=True,
              help="Track and fetch the latest source before resetting")
@click.option('--all', '-a', 'all_', default=False, is_flag=True,
              help="Reset all open workspaces")
@click.argument('elements', nargs=-1,
                type=click.Path(readable=False))
@click.pass_obj
def workspace_reset(app, soft, track_, all_, elements):
    """Reset a workspace to its original state"""

    # Check that the workspaces in question exist
    with app.initialized():

        if not (all_ or elements):
            element = app.context.guess_element()
            if element:
                elements = (element,)
            else:
                raise AppError('No elements specified to reset')

        if all_ and not app.stream.workspace_exists():
            raise AppError("No open workspaces to reset")

        if app.interactive and not soft and app.context.prompt_workspace_reset_hard:
            if not click.confirm('This will remove all your changes, are you sure?'):
                click.echo('Aborting', err=True)
                sys.exit(-1)

        if all_:
            elements = tuple(element_name for element_name, _ in app.context.get_workspaces().list())

        app.stream.workspace_reset(elements, soft=soft, track_first=track_)


##################################################################
#                     Workspace List Command                     #
##################################################################
@workspace.command(name='list', short_help="List open workspaces")
@click.pass_obj
def workspace_list(app):
    """List open workspaces"""

    with app.initialized():
        app.stream.workspace_list()


#############################################################
#                     Artifact Commands                     #
#############################################################
def _classify_artifacts(names, cas, project_directory):
    element_targets = []
    artifact_refs = []
    element_globs = []
    artifact_globs = []

    for name in names:
        if name.endswith('.bst'):
            if any(c in "*?[" for c in name):
                element_globs.append(name)
            else:
                element_targets.append(name)
        else:
            if any(c in "*?[" for c in name):
                artifact_globs.append(name)
            else:
                artifact_refs.append(name)

    if element_globs:
        for dirpath, _, filenames in os.walk(project_directory):
            for filename in filenames:
                element_path = os.path.join(dirpath, filename).lstrip(project_directory).lstrip('/')
                if any(fnmatch(element_path, glob) for glob in element_globs):
                    element_targets.append(element_path)

    if artifact_globs:
        artifact_refs.extend(ref for ref in cas.list_refs()
                             if any(fnmatch(ref, glob) for glob in artifact_globs))

    return element_targets, artifact_refs


@cli.group(short_help="Manipulate cached artifacts")
def artifact():
    """Manipulate cached artifacts"""


################################################################
#                     Artifact Log Command                     #
################################################################
@artifact.command(name='log', short_help="Show logs of an artifact")
@click.argument('artifacts', type=click.Path(), nargs=-1)
@click.pass_obj
def artifact_log(app, artifacts):
    """Show logs of all artifacts"""
    from .._exceptions import CASError
    from .._message import MessageType
    from .._pipeline import PipelineSelection
    from ..storage._casbaseddirectory import CasBasedDirectory

    with ExitStack() as stack:
        stack.enter_context(app.initialized())
        cache = app.context.artifactcache

        elements, artifacts = _classify_artifacts(artifacts, cache.cas,
                                                  app.project.directory)

        vdirs = []
        extractdirs = []
        if artifacts:
            for ref in artifacts:
                try:
                    cache_id = cache.cas.resolve_ref(ref, update_mtime=True)
                    vdir = CasBasedDirectory(cache.cas, cache_id)
                    vdirs.append(vdir)
                except CASError as e:
                    app._message(MessageType.WARN, "Artifact {} is not cached".format(ref), detail=str(e))
                    continue
        if elements:
            elements = app.stream.load_selection(elements, selection=PipelineSelection.NONE)
            for element in elements:
                if not element._cached():
                    app._message(MessageType.WARN, "Element {} is not cached".format(element))
                    continue
                ref = cache.get_artifact_fullname(element, element._get_cache_key())
                cache_id = cache.cas.resolve_ref(ref, update_mtime=True)
                vdir = CasBasedDirectory(cache.cas, cache_id)
                vdirs.append(vdir)

        for vdir in vdirs:
            # NOTE: If reading the logs feels unresponsive, here would be a good place to provide progress information.
            logsdir = vdir.descend(["logs"])
            td = stack.enter_context(TemporaryDirectory())
            logsdir.export_files(td, can_link=True)
            extractdirs.append(td)

        for extractdir in extractdirs:
            for log in (os.path.join(extractdir, log) for log in os.listdir(extractdir)):
                # NOTE: Should click gain the ability to pass files to the pager this can be optimised.
                with open(log) as f:
                    data = f.read()
                    click.echo_via_pager(data)


###################################################################
#                     Artifact Delete Command                     #
###################################################################
@artifact.command(name='delete', short_help="Delete matching artifacts")
@click.argument('artifacts', type=click.Path(), nargs=-1)
@click.pass_obj
def artifact_delete(app, artifacts):
    '''Delete matching artifacts from the cache'''
    from .._pipeline import PipelineSelection

    with app.initialized():
        cache = app.context.artifactcache

        elements, artifacts = _classify_artifacts(artifacts, cache.cas,
                                                  app.project.directory)

        if not elements and not artifacts:
            element = app.context.guess_element()
            if element is not None:
                elements = [element]

        # Remove specified elements and artifacts
        if elements:
            elements = app.stream.load_selection(elements, selection=PipelineSelection.NONE)
            for element in elements:
                cache_keys = set([element._get_cache_key(),
                                  element._get_cache_key(strength=_KeyStrength.WEAK)])
                for cache_key in cache_keys:
                    ref = cache.get_artifact_fullname(element, cache_key)
                    if cache.contains(element, cache_key):
                        cache.remove(ref, defer_prune=True)
                        click.echo("Removed {}.".format(ref))
                    else:
                        # If the ref is not present when we try to delete it, we should
                        # not fail but just continue to delete. The pruning will take care
                        # of any unreachable objects.
                        click.echo("WARNING: {}, not found in local cache - no delete required"
                                   .format(ref), err=True)
                        continue

        if artifacts:
            for ref in artifacts:
                if cache.contains_ref(ref):
                    cache.remove(ref, defer_prune=True)
                    click.echo("Removed {}.".format(ref))
                else:
                    # If the ref is not present when we try to delete it, we should
                    # not fail but just continue to delete. The pruning will take care
                    # of any unreachable objects.
                    click.echo("WARNING: {}, not found in local cache - no delete required"
                               .format(ref), err=True)
                    continue

        # Now we've removed all the refs, prune the unreachable objects
        cache.prune()


##################################################################
#                      DEPRECATED Commands                       #
##################################################################

# XXX: The following commands are now obsolete, but they are kept
# here along with all the options so that we can provide nice error
# messages when they are called.
# Also, note that these commands are hidden from the top-level help.

##################################################################
#                          Fetch Command                         #
##################################################################
@cli.command(short_help="Fetch sources in a pipeline", hidden=True)
@click.option('--except', 'except_', multiple=True,
              type=click.Path(readable=False),
              help="Except certain dependencies from fetching")
@click.option('--deps', '-d', default='plan',
              type=click.Choice(['none', 'plan', 'all']),
              help='The dependencies to fetch (default: plan)')
@click.option('--track', 'track_', default=False, is_flag=True,
              help="Track new source references before fetching")
@click.option('--track-cross-junctions', '-J', default=False, is_flag=True,
              help="Allow tracking to cross junction boundaries")
@click.argument('elements', nargs=-1,
                type=click.Path(readable=False))
@click.pass_obj
def fetch(app, elements, deps, track_, except_, track_cross_junctions):
    click.echo("This command is now obsolete. Use `bst source fetch` instead.", err=True)
    sys.exit(1)


##################################################################
#                          Track Command                         #
##################################################################
@cli.command(short_help="Track new source references", hidden=True)
@click.option('--except', 'except_', multiple=True,
              type=click.Path(readable=False),
              help="Except certain dependencies from tracking")
@click.option('--deps', '-d', default='none',
              type=click.Choice(['none', 'all']),
              help='The dependencies to track (default: none)')
@click.option('--cross-junctions', '-J', default=False, is_flag=True,
              help="Allow crossing junction boundaries")
@click.argument('elements', nargs=-1,
                type=click.Path(readable=False))
@click.pass_obj
def track(app, elements, deps, except_, cross_junctions):
    click.echo("This command is now obsolete. Use `bst source track` instead.", err=True)
    sys.exit(1)