/*
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements.  See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License.  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package api

import (
	"fmt"
	"net/http"
	"net/url"

	"github.com/apache/incubator-devlake/core/errors"
	"github.com/apache/incubator-devlake/core/plugin"
	"github.com/apache/incubator-devlake/helpers/pluginhelper/api"
	dsmodels "github.com/apache/incubator-devlake/helpers/pluginhelper/api/models"
	"github.com/apache/incubator-devlake/plugins/github/models"
)

func listGithubRemoteScopes(
	connection *models.GithubConnection,
	apiClient plugin.ApiClient,
	groupId string,
	page GithubRemotePagination,
) (
	children []dsmodels.DsRemoteApiScopeListEntry[models.GithubRepo],
	nextPage *GithubRemotePagination,
	err errors.Error,
) {
	if page.Page == 0 {
		page.Page = 1
	}
	if page.PerPage == 0 {
		page.PerPage = 100
	}

	if connection.AuthMethod == plugin.AUTH_METHOD_APPKEY {
		return listGithubAppInstalledRepos(apiClient, groupId, page)
	}
	if groupId == "" {
		return listGithubUserOrgs(apiClient, page)
	}
	return listGithubOwnerRepos(apiClient, groupId, page)
}

func listGithubUserOrgs(
	apiClient plugin.ApiClient,
	page GithubRemotePagination,
) (
	children []dsmodels.DsRemoteApiScopeListEntry[models.GithubRepo],
	nextPage *GithubRemotePagination,
	err errors.Error,
) {
	// user's own org
	if page.Page == 1 {
		userBody, err := apiClient.Get("user", nil, nil)
		if err != nil {
			return nil, nil, err
		}
		var o org
		errors.Must(api.UnmarshalResponse(userBody, &o))
		children = append(children, dsmodels.DsRemoteApiScopeListEntry[models.GithubRepo]{
			Type:     api.RAS_ENTRY_TYPE_GROUP,
			Id:       fmt.Sprintf("%v", o.Login),
			Name:     fmt.Sprintf("%v", o.Login),
			FullName: fmt.Sprintf("%v", o.Login),
		})
	}
	// user's orgs
	orgsBody, err := apiClient.Get(
		"user/orgs",
		url.Values{
			"page":     []string{fmt.Sprintf("%v", page.Page)},
			"per_page": []string{fmt.Sprintf("%v", page.PerPage)},
		},
		nil,
	)
	if err != nil {
		return nil, nil, err
	}
	var orgs []org
	if err := api.UnmarshalResponse(orgsBody, &orgs); err != nil {
		return nil, nil, err
	}
	for _, o := range orgs {
		children = append(children, dsmodels.DsRemoteApiScopeListEntry[models.GithubRepo]{
			Type:     api.RAS_ENTRY_TYPE_GROUP,
			Id:       fmt.Sprintf("%v", o.Login),
			Name:     fmt.Sprintf("%v", o.Login),
			FullName: fmt.Sprintf("%v", o.Login),
		})
	}
	// there may be more orgs
	if len(orgs) == page.PerPage {
		nextPage = &GithubRemotePagination{
			Page:    page.Page + 1,
			PerPage: page.PerPage,
		}
	}
	return children, nextPage, nil
}

// getOwnerInfo fetches the owner's type and ID from the GitHub API.
func getOwnerInfo(apiClient plugin.ApiClient, owner string) (ownerType string, ownerID int, err errors.Error) {
	resp, err := apiClient.Get(fmt.Sprintf("users/%s", owner), nil, nil)
	if err != nil {
		return "", 0, err
	}
	var info struct {
		ID   int    `json:"id"`
		Type string `json:"type"`
	}
	errors.Must(api.UnmarshalResponse(resp, &info))
	return info.Type, info.ID, nil
}

// getAuthenticatedUserID returns the ID of the currently authenticated user.
func getAuthenticatedUserID(apiClient plugin.ApiClient) (int, errors.Error) {
	resp, err := apiClient.Get("user", nil, nil)
	if err != nil {
		return 0, err
	}
	var user struct {
		ID int `json:"id"`
	}
	errors.Must(api.UnmarshalResponse(resp, &user))
	return user.ID, nil
}

// listGithubOwnerRepos lists repositories for a given owner (user or organization).
// It determines the owner type via the GitHub API and uses the appropriate endpoint:
// - For organizations: /orgs/{owner}/repos
// - For the authenticated user: /user/repos (includes private repos)
// - For other users: /users/{owner}/repos (public repos only)
func listGithubOwnerRepos(
	apiClient plugin.ApiClient,
	owner string,
	page GithubRemotePagination,
) (
	children []dsmodels.DsRemoteApiScopeListEntry[models.GithubRepo],
	nextPage *GithubRemotePagination,
	err errors.Error,
) {
	query := url.Values{
		"page":     []string{fmt.Sprintf("%v", page.Page)},
		"per_page": []string{fmt.Sprintf("%v", page.PerPage)},
		"type":     []string{"all"},
	}

	ownerType, ownerID, err := getOwnerInfo(apiClient, owner)
	if err != nil {
		return
	}

	var reposBody *http.Response
	var authUserID int
	switch ownerType {
	case "Organization":
		reposBody, err = apiClient.Get(fmt.Sprintf("orgs/%s/repos", owner), query, nil)
	case "User":
		authUserID, err = getAuthenticatedUserID(apiClient)
		if err != nil {
			return
		}
		if authUserID == ownerID {
			// Authenticated user's own account - includes private repos
			reposBody, err = apiClient.Get("user/repos", query, nil)
		} else {
			// Another user's account - public repos only
			reposBody, err = apiClient.Get(fmt.Sprintf("users/%s/repos", owner), query, nil)
		}
	default:
		// Fallback for unknown types
		reposBody, err = apiClient.Get(fmt.Sprintf("users/%s/repos", owner), query, nil)
	}
	if err != nil {
		return
	}

	var repos []repo
	errors.Must(api.UnmarshalResponse(reposBody, &repos))
	for _, repo := range repos {
		children = append(children, toRepoModel(&repo))
	}
	// there may be more repos
	if len(children) == page.PerPage {
		nextPage = &GithubRemotePagination{
			Page:    page.Page + 1,
			PerPage: page.PerPage,
		}
	}
	return
}

func listGithubAppInstalledRepos(
	apiClient plugin.ApiClient,
	org string,
	page GithubRemotePagination,
) (
	children []dsmodels.DsRemoteApiScopeListEntry[models.GithubRepo],
	nextPage *GithubRemotePagination,
	err errors.Error,
) {
	resApp, err := apiClient.Get("installation/repositories",
		url.Values{
			"page":     []string{fmt.Sprintf("%v", page.Page)},
			"per_page": []string{fmt.Sprintf("%v", page.PerPage)},
		},
		nil,
	)
	if err != nil {
		return nil, nil, err
	}
	var appRepos GithubAppRepoResult
	errors.Must(api.UnmarshalResponse(resApp, &appRepos))
	processedOrgs := make(map[string]struct{})
	for _, r := range appRepos.Repositories {
		orgName := r.Owner.Login
		// Return only the unique orgs when org is not selected
		if _, exists := processedOrgs[orgName]; !exists && orgName != "" && org == "" {
			children = append(children, dsmodels.DsRemoteApiScopeListEntry[models.GithubRepo]{
				Type:     api.RAS_ENTRY_TYPE_GROUP,
				ParentId: nil,
				Id:       fmt.Sprintf("%v", orgName),
				Name:     fmt.Sprintf("%v", orgName),
				FullName: fmt.Sprintf("%v", orgName),
			})
			processedOrgs[orgName] = struct{}{}
		}
		// Return only repos when org is selected
		if org != "" {
			children = append(children, toGithubAppRepoModel(&r))
		}
	}
	if len(appRepos.Repositories) == page.PerPage {
		nextPage = &GithubRemotePagination{
			Page:    page.Page + 1,
			PerPage: page.PerPage,
		}
	}
	return
}

func searchGithubRepos(
	apiClient plugin.ApiClient,
	params *dsmodels.DsRemoteApiScopeSearchParams,
) (
	children []dsmodels.DsRemoteApiScopeListEntry[models.GithubRepo],
	err errors.Error,
) {
	res, err := apiClient.Get(
		"search/repositories",
		url.Values{
			"q":        []string{params.Search},
			"page":     []string{fmt.Sprintf("%v", params.Page)},
			"per_page": []string{fmt.Sprintf("%v", params.PageSize)},
		},
		nil,
	)
	if err != nil {
		return nil, err
	}
	var resBody struct {
		Items []repo `json:"items"`
	}
	err = api.UnmarshalResponse(res, &resBody)
	if err != nil {
		return nil, err
	}
	for _, r := range resBody.Items {
		children = append(children, toRepoModel(&r))
	}
	return
}

func toRepoModel(r *repo) dsmodels.DsRemoteApiScopeListEntry[models.GithubRepo] {
	parentId := fmt.Sprintf("%v", r.Owner.Login)
	return dsmodels.DsRemoteApiScopeListEntry[models.GithubRepo]{
		Type:     api.RAS_ENTRY_TYPE_SCOPE,
		ParentId: &parentId,
		Id:       fmt.Sprintf("%v", r.ID),
		Name:     fmt.Sprintf("%v", r.Name),
		FullName: fmt.Sprintf("%v", r.FullName),
		Data: &models.GithubRepo{
			GithubId:    r.ID,
			Name:        r.Name,
			FullName:    r.FullName,
			HTMLUrl:     r.HTMLURL,
			Description: r.Description,
			OwnerId:     r.Owner.ID,
			CloneUrl:    r.CloneURL,
			CreatedDate: r.CreatedAt,
			UpdatedDate: r.UpdatedAt,
		},
	}
}

func toGithubAppRepoModel(r *GithubAppRepo) dsmodels.DsRemoteApiScopeListEntry[models.GithubRepo] {
	parentId := fmt.Sprintf("%v", r.Owner.Login)
	return dsmodels.DsRemoteApiScopeListEntry[models.GithubRepo]{
		Type:     api.RAS_ENTRY_TYPE_SCOPE,
		ParentId: &parentId,
		Id:       fmt.Sprintf("%v", r.ID),
		Name:     fmt.Sprintf("%v", r.Name),
		FullName: fmt.Sprintf("%v", r.FullName),
		Data: &models.GithubRepo{
			GithubId:    r.ID,
			Name:        r.Name,
			FullName:    r.FullName,
			HTMLUrl:     r.HTMLURL,
			Description: r.Description,
			OwnerId:     r.Owner.ID,
			CloneUrl:    r.CloneURL,
			CreatedDate: r.CreatedAt,
			UpdatedDate: r.UpdatedAt,
		},
	}
}

// RemoteScopes list all available scopes on the remote server
// @Summary list all available scopes on the remote server
// @Description list all available scopes on the remote server
// @Accept application/json
// @Param connectionId path int false "connection ID"
// @Param groupId query string false "group ID"
// @Param pageToken query string false "page Token"
// @Failure 400  {object} shared.ApiBody "Bad Request"
// @Failure 500  {object} shared.ApiBody "Internal Error"
// @Success 200  {object} dsmodels.DsRemoteApiScopeList[models.GithubRepo]
// @Tags plugins/github
// @Router /plugins/github/connections/{connectionId}/remote-scopes [GET]
func RemoteScopes(input *plugin.ApiResourceInput) (*plugin.ApiResourceOutput, errors.Error) {
	return raScopeList.Get(input)
}

// SearchRemoteScopes searches scopes on the remote server
// @Summary searches scopes on the remote server
// @Description searches scopes on the remote server
// @Accept application/json
// @Param connectionId path int false "connection ID"
// @Param search query string false "search"
// @Param page query int false "page number"
// @Param pageSize query int false "page size per page"
// @Failure 400  {object} shared.ApiBody "Bad Request"
// @Failure 500  {object} shared.ApiBody "Internal Error"
// @Success 200  {object} dsmodels.DsRemoteApiScopeList[models.GithubRepo] "the parentIds are always null"
// @Tags plugins/github
// @Router /plugins/github/connections/{connectionId}/search-remote-scopes [GET]
func SearchRemoteScopes(input *plugin.ApiResourceInput) (*plugin.ApiResourceOutput, errors.Error) {
	return raScopeSearch.Get(input)
}

// @Summary Remote server API proxy
// @Description Forward API requests to the specified remote server
// @Param connectionId path int true "connection ID"
// @Param path path string true "path to a API endpoint"
// @Tags plugins/github
// @Router /plugins/github/connections/{connectionId}/proxy/{path} [GET]
func Proxy(input *plugin.ApiResourceInput) (*plugin.ApiResourceOutput, errors.Error) {
	return raProxy.Proxy(input)
}