// 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 controllers

import (
	"fmt"
	"strconv"
	"strings"
)

type Member struct {
	Name string
	// Kubernetes namespace this member runs in.
	Namespace string
	// ID field can be 0, which is unknown ID.
	// We know the ID of a member when we get the member information from dbmaster,
	// but not from Kubernetes pod list.
	ID              uint64
	Phase           string
	Created         bool
	RunningAndReady bool
	Version         string
}

func (m Member) Ordinal() int {
	idx := strings.LastIndex(m.Name, "-")
	id, _ := strconv.ParseInt(m.Name[idx+1:], 10, 32)
	return int(id)
}

type MemberSet map[string]*Member

// the set of all members of s1 that are not members of s2
func (ms MemberSet) Diff(other MemberSet) MemberSet {
	diff := MemberSet{}
	for n, m := range ms {
		if _, ok := other[n]; !ok {
			diff[n] = m
		}
	}
	return diff
}

func (ms MemberSet) Get(id int) *Member {
	for _, m := range ms {
		idx := strings.LastIndex(m.Name, "-")
		mid, _ := strconv.ParseInt(m.Name[idx+1:], 10, 32)
		if int(mid) == id {
			return m
		}
	}
	return nil
}

// IsEqual tells whether two member sets are equal by checking
// - they have the same set of members and member equality are judged by Name only.
func (ms MemberSet) IsEqual(other MemberSet) bool {
	if ms.Size() != other.Size() {
		return false
	}
	for n := range ms {
		if _, ok := other[n]; !ok {
			return false
		}
	}
	return true
}

func (ms MemberSet) Size() int {
	return len(ms)
}

func (ms MemberSet) String() string {
	var mstring []string

	for m, v := range ms {
		mstring = append(mstring, fmt.Sprintf("%s:%s", m, v.Version))
	}
	return strings.Join(mstring, ",")
}

func (ms MemberSet) PickOne() *Member {
	for _, m := range ms {
		return m
	}
	panic("empty")
}

func (ms MemberSet) Add(m *Member) {
	ms[m.Name] = m
}

func (ms MemberSet) Remove(name string) {
	delete(ms, name)
}

func (ms MemberSet) Ordinals() map[int]bool {
	ids := map[int]bool{}
	for _, m := range ms {
		ids[m.Ordinal()] = true
	}
	return ids
}

func (ms MemberSet) Names() []string {
	names := make([]string, 0)
	for _, m := range ms {
		names = append(names, m.Name)
	}
	return names
}

func (ms MemberSet) Duplicate() MemberSet {
	r := MemberSet{}
	for k, v := range ms {
		r[k] = v
	}
	return r
}

func allMembersHealth(ms MemberSet) bool {
	for _, m := range ms {
		if !m.RunningAndReady {
			return false
		}
	}
	return true
}