package chat

import (
	"encoding/json"
	"log/slog"
	"os"
	"path/filepath"
	"sync"

	"github.com/ayn2op/discordo/internal/consts"
	"github.com/diamondburned/arikawa/v3/discord"
)

type guildState struct {
	ExpandedGuilds   map[discord.GuildID]bool   `json:"expanded_guilds"`
	ExpandedChannels map[discord.ChannelID]bool `json:"expanded_channels,omitempty"`
	mu               sync.RWMutex
}

var stateFilePath = filepath.Join(consts.CacheDir(), "state.json")

func loadGuildState() *guildState {
	gs := &guildState{
		ExpandedGuilds:   make(map[discord.GuildID]bool),
		ExpandedChannels: make(map[discord.ChannelID]bool),
	}
	data, err := os.ReadFile(stateFilePath)
	if err != nil {
		return gs
	}
	if err := json.Unmarshal(data, gs); err != nil {
		slog.Warn("failed to parse guild state", "err", err)
		return &guildState{
			ExpandedGuilds:   make(map[discord.GuildID]bool),
			ExpandedChannels: make(map[discord.ChannelID]bool),
		}
	}
	if gs.ExpandedGuilds == nil {
		gs.ExpandedGuilds = make(map[discord.GuildID]bool)
	}
	if gs.ExpandedChannels == nil {
		gs.ExpandedChannels = make(map[discord.ChannelID]bool)
	}
	return gs
}

func (gs *guildState) save() {
	gs.mu.Lock()
	defer gs.mu.Unlock()
	atomicSaveJSON(stateFilePath, gs)
}

func (gs *guildState) setExpanded(id discord.GuildID, expanded bool) {
	gs.mu.Lock()
	if expanded {
		gs.ExpandedGuilds[id] = true
	} else {
		delete(gs.ExpandedGuilds, id)
	}
	gs.mu.Unlock()
	gs.save()
}

func (gs *guildState) isExpanded(id discord.GuildID) bool {
	gs.mu.RLock()
	defer gs.mu.RUnlock()
	return gs.ExpandedGuilds[id]
}

func (gs *guildState) setChannelExpanded(id discord.ChannelID, expanded bool) {
	gs.mu.Lock()
	if expanded {
		gs.ExpandedChannels[id] = true
	} else {
		delete(gs.ExpandedChannels, id)
	}
	gs.mu.Unlock()
	gs.save()
}

func (gs *guildState) isChannelExpanded(id discord.ChannelID, defaultExpanded bool) bool {
	gs.mu.RLock()
	defer gs.mu.RUnlock()
	if v, ok := gs.ExpandedChannels[id]; ok {
		return v
	}
	return defaultExpanded
}