package laniakea

import (
	"fmt"
	"os"
	"sort"
	"strings"
	"time"

	"git.nix13.pw/scuroneko/extypes"
	"git.nix13.pw/scuroneko/laniakea/tgapi"
	"git.nix13.pw/scuroneko/slog"
)

type BotOpts struct {
	Token            string
	Debug            bool
	ErrorTemplate    string
	Prefixes         []string
	UpdateTypes      []string
	LoggerBasePath   string
	UseRequestLogger bool
	WriteToFile      bool
	UseTestServer    bool
	APIUrl           string
}

func LoadOptsFromEnv() *BotOpts {
	return &BotOpts{
		Token:            os.Getenv("TG_TOKEN"),
		Debug:            os.Getenv("DEBUG") == "true",
		ErrorTemplate:    os.Getenv("ERROR_TEMPLATE"),
		Prefixes:         LoadPrefixesFromEnv(),
		UpdateTypes:      strings.Split(os.Getenv("UPDATE_TYPES"), ";"),
		UseRequestLogger: os.Getenv("USE_REQ_LOG") == "true",
		WriteToFile:      os.Getenv("WRITE_TO_FILE") == "true",
		UseTestServer:    os.Getenv("USE_TEST_SERVER") == "true",
		APIUrl:           os.Getenv("API_URL"),
	}
}
func LoadPrefixesFromEnv() []string {
	prefixesS, exists := os.LookupEnv("PREFIXES")
	if !exists {
		return []string{"/"}
	}
	return strings.Split(prefixesS, ";")
}

type DbContext interface{}
type Bot[T DbContext] struct {
	token         string
	debug         bool
	errorTemplate string

	logger        *slog.Logger
	RequestLogger *slog.Logger

	plugins     []Plugin[T]
	middlewares []Middleware[T]
	prefixes    []string
	runners     []Runner[T]

	api       *tgapi.API
	uploader  *tgapi.Uploader
	dbContext *T
	l10n      *L10n

	dbWriterRequested extypes.Slice[*slog.Logger]

	updateOffset int
	updateTypes  []tgapi.UpdateType
	updateQueue  *extypes.Queue[*tgapi.Update]
}

func NewBot[T any](opts *BotOpts) *Bot[T] {
	updateQueue := extypes.CreateQueue[*tgapi.Update](512)

	apiOpts := tgapi.NewAPIOpts(opts.Token).SetAPIUrl(opts.APIUrl).UseTestServer(opts.UseTestServer)
	api := tgapi.NewAPI(apiOpts)

	uploader := tgapi.NewUploader(api)

	bot := &Bot[T]{
		updateOffset:      0,
		errorTemplate:     "%s",
		updateQueue:       updateQueue,
		api:               api,
		uploader:          uploader,
		debug:             opts.Debug,
		prefixes:          opts.Prefixes,
		token:             opts.Token,
		plugins:           make([]Plugin[T], 0),
		updateTypes:       make([]tgapi.UpdateType, 0),
		runners:           make([]Runner[T], 0),
		dbWriterRequested: make([]*slog.Logger, 0),
		l10n:              &L10n{},
	}
	bot.dbWriterRequested = bot.dbWriterRequested.Push(api.GetLogger()).Push(uploader.GetLogger())

	if len(opts.ErrorTemplate) > 0 {
		bot.errorTemplate = opts.ErrorTemplate
	}
	if len(opts.LoggerBasePath) == 0 {
		opts.LoggerBasePath = "./"
	}
	bot.initLoggers(opts)

	u, err := api.GetMe()
	if err != nil {
		_ = api.CloseApi()
		_ = uploader.Close()
		bot.logger.Fatal(err)
	}
	bot.logger.Infof("Authorized as %s\n", u.FirstName)

	return bot
}
func (bot *Bot[T]) Close() error {
	if err := bot.uploader.Close(); err != nil {
		bot.logger.Errorln(err)
	}
	if err := bot.api.CloseApi(); err != nil {
		bot.logger.Errorln(err)
	}
	if err := bot.RequestLogger.Close(); err != nil {
		bot.logger.Errorln(err)
	}
	if err := bot.logger.Close(); err != nil {
		return err
	}
	return nil
}
func (bot *Bot[T]) initLoggers(opts *BotOpts) {
	level := slog.FATAL
	if opts.Debug {
		level = slog.DEBUG
	}

	bot.logger = slog.CreateLogger().Level(level).Prefix("BOT")
	bot.logger.AddWriter(bot.logger.CreateJsonStdoutWriter())
	if opts.WriteToFile {
		path := fmt.Sprintf("%s/main.log", strings.TrimRight(opts.LoggerBasePath, "/"))
		fileWriter, err := bot.logger.CreateTextFileWriter(path)
		if err != nil {
			bot.logger.Fatal(err)
		}
		bot.logger.AddWriter(fileWriter)
	}

	if opts.UseRequestLogger {
		bot.RequestLogger = slog.CreateLogger().Level(level).Prefix("REQUESTS")
		bot.RequestLogger.AddWriter(bot.RequestLogger.CreateJsonStdoutWriter())
		if opts.WriteToFile {
			path := fmt.Sprintf("%s/requests.log", strings.TrimRight(opts.LoggerBasePath, "/"))
			fileWriter, err := bot.RequestLogger.CreateTextFileWriter(path)
			if err != nil {
				bot.logger.Fatal(err)
			}
			bot.RequestLogger.AddWriter(fileWriter)
		}
	}
}

func (bot *Bot[T]) GetUpdateOffset() int                    { return bot.updateOffset }
func (bot *Bot[T]) SetUpdateOffset(offset int)              { bot.updateOffset = offset }
func (bot *Bot[T]) GetUpdateTypes() []tgapi.UpdateType      { return bot.updateTypes }
func (bot *Bot[T]) GetQueue() *extypes.Queue[*tgapi.Update] { return bot.updateQueue }
func (bot *Bot[T]) GetLogger() *slog.Logger                 { return bot.logger }
func (bot *Bot[T]) GetDBContext() *T                        { return bot.dbContext }
func (bot *Bot[T]) L10n(lang, key string) string            { return bot.l10n.Translate(lang, key) }

func (bot *Bot[T]) AddDatabaseLogger(writer func(db *T) slog.LoggerWriter) *Bot[T] {
	w := writer(bot.dbContext)
	bot.logger.AddWriter(w)
	if bot.RequestLogger != nil {
		bot.RequestLogger.AddWriter(w)
	}
	for _, l := range bot.dbWriterRequested {
		l.AddWriter(w)
	}
	return bot
}

func (bot *Bot[T]) DatabaseContext(ctx *T) *Bot[T] {
	bot.dbContext = ctx
	return bot
}
func (bot *Bot[T]) UpdateTypes(t ...tgapi.UpdateType) *Bot[T] {
	bot.updateTypes = make([]tgapi.UpdateType, 0)
	bot.updateTypes = append(bot.updateTypes, t...)
	return bot
}
func (bot *Bot[T]) AddUpdateType(t ...tgapi.UpdateType) *Bot[T] {
	bot.updateTypes = append(bot.updateTypes, t...)
	return bot
}
func (bot *Bot[T]) AddPrefixes(prefixes ...string) *Bot[T] {
	bot.prefixes = append(bot.prefixes, prefixes...)
	return bot
}
func (bot *Bot[T]) ErrorTemplate(s string) *Bot[T] {
	bot.errorTemplate = s
	return bot
}
func (bot *Bot[T]) Debug(debug bool) *Bot[T] {
	bot.debug = debug
	return bot
}
func (bot *Bot[T]) AddPlugins(plugin ...*Plugin[T]) *Bot[T] {
	for _, p := range plugin {
		bot.plugins = append(bot.plugins, *p)
		bot.logger.Debugln(fmt.Sprintf("plugins with name \"%s\" registered", p.Name))
	}
	return bot
}
func (bot *Bot[T]) AddMiddleware(middleware ...Middleware[T]) *Bot[T] {
	bot.middlewares = append(bot.middlewares, middleware...)
	for _, m := range middleware {
		bot.logger.Debugln(fmt.Sprintf("middleware with name \"%s\" registered", m.name))
	}

	sort.Slice(bot.middlewares, func(i, j int) bool {
		first := bot.middlewares[i]
		second := bot.middlewares[j]
		if first.order == second.order {
			return first.name < second.name
		}
		return first.order < second.order
	})

	return bot
}
func (bot *Bot[T]) AddRunner(runner Runner[T]) *Bot[T] {
	bot.runners = append(bot.runners, runner)
	bot.logger.Debugln(fmt.Sprintf("runner with name \"%s\" registered", runner.name))
	return bot
}
func (bot *Bot[T]) AddL10n(l *L10n) *Bot[T] {
	bot.l10n = l
	return bot
}

func (bot *Bot[T]) Run() {
	if len(bot.prefixes) == 0 {
		bot.logger.Fatalln("no prefixes defined")
		return
	}

	if len(bot.plugins) == 0 {
		bot.logger.Fatalln("no plugins defined")
		return
	}

	bot.ExecRunners()

	bot.logger.Infoln("Bot running. Press CTRL+C to exit.")
	go func() {
		for {
			_, err := bot.Updates()
			if err != nil {
				bot.logger.Errorln(err)
			}
		}
	}()

	for {
		queue := bot.updateQueue
		if queue.IsEmpty() {
			time.Sleep(time.Millisecond * 25)
			continue
		}

		u := queue.Dequeue()
		if u == nil {
			bot.logger.Errorln("update is nil")
			continue
		}

		bot.handle(u)
	}
}