package cli

import (
	"context"
	"errors"
	"flag"
	"fmt"
	"io"
	"log/slog"
	"os"
	"time"

	"github.com/bwmarrin/discordgo"
	"github.com/openclaw/crawlkit/embed"
	"github.com/openclaw/discrawl/internal/config"
	"github.com/openclaw/discrawl/internal/discord"
	"github.com/openclaw/discrawl/internal/share"
	"github.com/openclaw/discrawl/internal/store"
	"github.com/openclaw/discrawl/internal/syncer"
)

type cliError struct {
	code int
	err  error
}

func (e *cliError) Error() string {
	return e.err.Error()
}

func (e *cliError) Unwrap() error {
	return e.err
}

func ExitCode(err error) int {
	if err == nil {
		return 0
	}
	if errors.Is(err, context.Canceled) {
		return 1
	}
	var codeErr *cliError
	if errors.As(err, &codeErr) {
		return codeErr.code
	}
	return 1
}

func Run(ctx context.Context, args []string, stdout, stderr io.Writer) error {
	if len(args) == 0 || args[0] == "help" || args[0] == "--help" || args[0] == "-h" {
		printUsage(stdout)
		return nil
	}
	global := flag.NewFlagSet("discrawl", flag.ContinueOnError)
	global.SetOutput(io.Discard)
	configPath := global.String("config", "", "")
	jsonOut := global.Bool("json", false, "")
	plainOut := global.Bool("plain", false, "")
	quiet := global.Bool("quiet", false, "")
	global.BoolVar(quiet, "q", false, "")
	verbose := global.Bool("verbose", false, "")
	global.BoolVar(verbose, "v", false, "")
	versionFlag := global.Bool("version", false, "")
	global.Bool("no-color", false, "")
	if err := global.Parse(args); err != nil {
		return usageErr(err)
	}
	if *versionFlag {
		_, _ = io.WriteString(stdout, version+"\n")
		return nil
	}
	rest := global.Args()
	if len(rest) == 0 || rest[0] == "help" || rest[0] == "--help" || rest[0] == "-h" {
		printUsage(stdout)
		return nil
	}
	if rest[0] == "version" {
		_, _ = io.WriteString(stdout, version+"\n")
		return nil
	}
	level := slog.LevelInfo
	if *quiet {
		level = slog.LevelError
	}
	if *verbose {
		level = slog.LevelDebug
	}
	runtime := &runtime{
		ctx:        ctx,
		configPath: config.ResolvePath(*configPath),
		stdout:     stdout,
		stderr:     stderr,
		json:       *jsonOut,
		plain:      *plainOut,
		logger:     slog.New(slog.NewTextHandler(stderr, &slog.HandlerOptions{Level: level})),
	}
	return runtime.dispatch(rest)
}

type runtime struct {
	ctx         context.Context
	configPath  string
	cfg         config.Config
	stdout      io.Writer
	stderr      io.Writer
	json        bool
	plain       bool
	logger      *slog.Logger
	store       *store.Store
	client      discordClient
	syncer      syncService
	dbLockHeld  bool
	lockStarted time.Time
	openStore   func(context.Context, string) (*store.Store, error)
	newDiscord  func(config.Config) (discordClient, error)
	newSyncer   func(syncer.Client, *store.Store, *slog.Logger) syncService
	newEmbed    func(config.EmbeddingsConfig) (embed.Provider, error)
	now         func() time.Time
}

func crawlkitEmbeddingConfig(cfg config.EmbeddingsConfig) embed.Config {
	return embed.Config{
		Provider:       cfg.Provider,
		Model:          cfg.Model,
		BaseURL:        cfg.BaseURL,
		APIKeyEnv:      cfg.APIKeyEnv,
		RequestTimeout: cfg.RequestTimeout,
		MaxInputChars:  cfg.MaxInputChars,
	}
}

type discordClient interface {
	syncer.Client
	Close() error
	Self(context.Context) (*discordgo.User, error)
	Guilds(context.Context) ([]*discordgo.UserGuild, error)
}

type syncService interface {
	DiscoverGuilds(context.Context) ([]*discordgo.UserGuild, error)
	Sync(context.Context, syncer.SyncOptions) (syncer.SyncStats, error)
	RunTail(context.Context, []string, time.Duration) error
}

type attachmentTextConfigurer interface {
	SetAttachmentTextEnabled(bool)
}

func (r *runtime) dispatch(rest []string) error {
	switch rest[0] {
	case "metadata":
		return r.runMetadata(rest[1:])
	case "init":
		return r.runInit(rest[1:])
	case "sync":
		updateMode, err := syncShareUpdateMode(rest[1:])
		if err != nil {
			return usageErr(err)
		}
		return r.withLocalStoreUpdateLocked(updateMode, true, func() error { return r.runSync(rest[1:]) })
	case "tail":
		return r.withServicesLocked(true, func() error { return r.runTail(rest[1:]) })
	case "wiretap":
		return r.withLocalStoreLocked(false, func() error { return r.runWiretap(rest[1:]) })
	case "tap", "cache-import":
		return r.withLocalStoreLocked(false, func() error { return r.runWiretap(rest[1:]) })
	case "search":
		autoShareUpdate := !hasBoolFlag(rest[1:], "--dm")
		return r.withLocalStoreRead(autoShareUpdate, func() error { return r.runSearch(rest[1:]) })
	case "tui":
		if hasHelpArg(rest[1:]) {
			return r.runTUI(rest[1:])
		}
		return r.withLocalStoreReadOnly(func() error { return r.runTUI(rest[1:]) })
	case "messages":
		if hasBoolFlag(rest[1:], "--sync") && !hasBoolFlag(rest[1:], "--dm") {
			return r.withServicesAutoLocked(true, true, true, func() error { return r.runMessages(rest[1:]) })
		}
		autoShareUpdate := !hasBoolFlag(rest[1:], "--dm")
		return r.withLocalStoreRead(autoShareUpdate, func() error { return r.runMessages(rest[1:]) })
	case "digest":
		return r.withLocalStoreRead(true, func() error { return r.runDigest(rest[1:]) })
	case "analytics":
		return r.runAnalytics(rest[1:])
	case "dms":
		return r.withLocalStoreRead(false, func() error { return r.runDirectMessages(rest[1:]) })
	case "mentions":
		return r.withLocalStoreRead(true, func() error { return r.runMentions(rest[1:]) })
	case "embed":
		return r.withLocalStoreLocked(true, func() error { return r.runEmbed(rest[1:]) })
	case "sql":
		if boolFlagEnabled(rest[1:], "--unsafe") {
			return r.withLocalStoreLocked(true, func() error { return r.runSQL(rest[1:]) })
		}
		return r.withLocalStoreRead(true, func() error { return r.runSQL(rest[1:]) })
	case "members":
		return r.withLocalStoreRead(true, func() error { return r.runMembers(rest[1:]) })
	case "channels":
		return r.withLocalStoreRead(true, func() error { return r.runChannels(rest[1:]) })
	case "status":
		return r.withLocalStoreReadOnly(func() error { return r.runStatus(rest[1:]) })
	case "report":
		return r.withLocalStoreRead(true, func() error { return r.runReport(rest[1:]) })
	case "publish":
		return r.withServicesAutoLocked(false, false, true, func() error { return r.runPublish(rest[1:]) })
	case "subscribe":
		return r.runSubscribe(rest[1:])
	case "update":
		return r.withServicesAutoLocked(false, false, true, func() error { return r.runUpdate(rest[1:]) })
	case "doctor":
		return r.runDoctor(rest[1:])
	default:
		return usageErr(fmt.Errorf("unknown command %q", rest[0]))
	}
}

func (r *runtime) withServices(withDiscord bool, fn func() error) error {
	return r.withServicesAuto(withDiscord, !withDiscord, fn)
}

func (r *runtime) withServicesLocked(withDiscord bool, fn func() error) error {
	return r.withServicesAutoLocked(withDiscord, !withDiscord, true, fn)
}

func (r *runtime) withLocalStoreLocked(autoShareUpdate bool, fn func() error) error {
	return r.withLocalStoreUpdateLocked(boolShareUpdateMode(autoShareUpdate), true, fn)
}

func (r *runtime) withLocalStoreDefault(autoShareUpdate bool, fn func() error) error {
	return r.withLocalStoreUpdateLocked(boolShareUpdateMode(autoShareUpdate), false, fn)
}

func (r *runtime) withLocalStoreDefaultLocked(autoShareUpdate, lockDB bool, fn func() error) error {
	return r.withLocalStoreUpdateLocked(boolShareUpdateMode(autoShareUpdate), lockDB, fn)
}

func (r *runtime) withLocalStoreRead(autoShareUpdate bool, fn func() error) error {
	return r.withLocalStoreReadUpdate(boolShareUpdateMode(autoShareUpdate), fn)
}

func (r *runtime) withLocalStoreReadUpdate(updateMode shareUpdateMode, fn func() error) error {
	cfg, err := config.Load(r.configPath)
	if err != nil {
		if !errors.Is(err, os.ErrNotExist) {
			return configErr(err)
		}
		cfg = config.Default()
		if err := cfg.Normalize(); err != nil {
			return configErr(err)
		}
	}
	if err := config.EnsureRuntimeDirs(cfg); err != nil {
		return configErr(err)
	}
	dbPath, err := config.ExpandPath(cfg.DBPath)
	if err != nil {
		return configErr(err)
	}
	r.cfg = cfg
	if r.shouldAutoUpdateShare(updateMode) {
		if err := r.autoUpdateShareIfLockAvailable(dbPath, updateMode); err != nil {
			return err
		}
	}
	return r.openLocalStoreReadOnly(dbPath, fn)
}

func (r *runtime) withLocalStoreUpdateLocked(updateMode shareUpdateMode, lockDB bool, fn func() error) error {
	cfg, err := config.Load(r.configPath)
	if err != nil {
		if !errors.Is(err, os.ErrNotExist) {
			return configErr(err)
		}
		cfg = config.Default()
		if err := cfg.Normalize(); err != nil {
			return configErr(err)
		}
	}
	if err := config.EnsureRuntimeDirs(cfg); err != nil {
		return configErr(err)
	}
	dbPath, err := config.ExpandPath(cfg.DBPath)
	if err != nil {
		return configErr(err)
	}
	r.cfg = cfg
	if lockDB {
		return r.withSyncLock(func() error {
			return r.openLocalStore(dbPath, updateMode, fn)
		})
	}
	return r.openLocalStore(dbPath, updateMode, fn)
}

func (r *runtime) shouldAutoUpdateShare(mode shareUpdateMode) bool {
	return os.Getenv("DISCRAWL_NO_AUTO_UPDATE") != "1" &&
		r.cfg.ShareEnabled() &&
		(mode == shareUpdateForce || mode == shareUpdateAuto || (mode == shareUpdateConfigured && r.cfg.Share.AutoUpdate))
}

func (r *runtime) autoUpdateShareIfLockAvailable(dbPath string, updateMode shareUpdateMode) error {
	locked, err := r.tryWithSyncLock(func() error {
		storeFactory := r.openStore
		if storeFactory == nil {
			storeFactory = store.Open
		}
		var openErr error
		r.store, openErr = storeFactory(r.ctx, dbPath)
		if openErr != nil {
			return dbErr(openErr)
		}
		defer func() {
			_ = r.store.Close()
			r.store = nil
		}()
		return r.autoUpdateShare(updateMode)
	})
	if err != nil {
		return err
	}
	if !locked {
		r.logger.Info("share update skipped; sync lock is held")
	}
	return nil
}

func (r *runtime) openLocalStore(dbPath string, updateMode shareUpdateMode, fn func() error) error {
	storeFactory := r.openStore
	if storeFactory == nil {
		storeFactory = store.Open
	}
	var err error
	r.store, err = storeFactory(r.ctx, dbPath)
	if err != nil {
		return dbErr(err)
	}
	defer func() { _ = r.store.Close() }()
	if updateMode != shareUpdateNever && os.Getenv("DISCRAWL_NO_AUTO_UPDATE") != "1" {
		if err := r.autoUpdateShare(updateMode); err != nil {
			return err
		}
	}
	return fn()
}

func (r *runtime) withLocalStoreReadOnly(fn func() error) error {
	cfg, err := config.Load(r.configPath)
	if err != nil {
		if !errors.Is(err, os.ErrNotExist) {
			return configErr(err)
		}
		cfg = config.Default()
		if err := cfg.Normalize(); err != nil {
			return configErr(err)
		}
	}
	dbPath, err := config.ExpandPath(cfg.DBPath)
	if err != nil {
		return configErr(err)
	}
	r.cfg = cfg
	var openErr error
	r.store, openErr = store.OpenReadOnly(r.ctx, dbPath)
	if openErr != nil {
		if errors.Is(openErr, os.ErrNotExist) {
			r.store = nil
			return fn()
		}
		return dbErr(openErr)
	}
	defer func() { _ = r.store.Close() }()
	return fn()
}

func (r *runtime) openLocalStoreReadOnly(dbPath string, fn func() error) error {
	var openErr error
	r.store, openErr = store.OpenReadOnly(r.ctx, dbPath)
	if openErr != nil {
		if errors.Is(openErr, os.ErrNotExist) {
			storeFactory := r.openStore
			if storeFactory == nil {
				storeFactory = store.Open
			}
			r.store, openErr = storeFactory(r.ctx, dbPath)
			if openErr == nil {
				defer func() { _ = r.store.Close() }()
				return fn()
			}
		}
		if errors.Is(openErr, store.ErrSchemaVersionMismatch) {
			if err := r.withSyncLock(func() error {
				storeFactory := r.openStore
				if storeFactory == nil {
					storeFactory = store.Open
				}
				var migrateErr error
				r.store, migrateErr = storeFactory(r.ctx, dbPath)
				if migrateErr != nil {
					return dbErr(migrateErr)
				}
				closeErr := r.store.Close()
				r.store = nil
				return closeErr
			}); err != nil {
				return err
			}
			r.store, openErr = store.OpenReadOnly(r.ctx, dbPath)
			if openErr == nil {
				defer func() { _ = r.store.Close() }()
				return fn()
			}
		}
		return dbErr(openErr)
	}
	defer func() { _ = r.store.Close() }()
	return fn()
}

func (r *runtime) withServicesAuto(withDiscord, autoShareUpdate bool, fn func() error) error {
	return r.withServicesAutoLocked(withDiscord, autoShareUpdate, false, fn)
}

func (r *runtime) withServicesAutoLocked(withDiscord, autoShareUpdate, lockDB bool, fn func() error) error {
	return r.withServicesUpdateLocked(withDiscord, boolShareUpdateMode(autoShareUpdate), lockDB, fn)
}

func (r *runtime) withServicesUpdateLocked(withDiscord bool, updateMode shareUpdateMode, lockDB bool, fn func() error) error {
	cfg, err := config.Load(r.configPath)
	if err != nil {
		return configErr(err)
	}
	if err := config.EnsureRuntimeDirs(cfg); err != nil {
		return configErr(err)
	}
	dbPath, err := config.ExpandPath(cfg.DBPath)
	if err != nil {
		return configErr(err)
	}
	r.cfg = cfg
	if lockDB {
		return r.withSyncLock(func() error {
			return r.openServices(dbPath, withDiscord, updateMode, fn)
		})
	}
	return r.openServices(dbPath, withDiscord, updateMode, fn)
}

func (r *runtime) openServices(dbPath string, withDiscord bool, updateMode shareUpdateMode, fn func() error) error {
	storeFactory := r.openStore
	if storeFactory == nil {
		storeFactory = store.Open
	}
	var err error
	r.store, err = storeFactory(r.ctx, dbPath)
	if err != nil {
		return dbErr(err)
	}
	defer func() { _ = r.store.Close() }()
	if updateMode != shareUpdateNever && os.Getenv("DISCRAWL_NO_AUTO_UPDATE") != "1" {
		if err := r.autoUpdateShare(updateMode); err != nil {
			return err
		}
	}
	if withDiscord {
		if err := r.ensureDiscordServices(); err != nil {
			return err
		}
		if r.client != nil {
			defer func() { _ = r.client.Close() }()
		}
	}
	return fn()
}

func (r *runtime) ensureDiscordServices() error {
	discordFactory := r.newDiscord
	if discordFactory == nil {
		discordFactory = func(cfg config.Config) (discordClient, error) {
			token, err := config.ResolveDiscordToken(cfg)
			if err != nil {
				return nil, err
			}
			return discord.New(token.Token)
		}
	}
	client, err := discordFactory(r.cfg)
	if err != nil {
		return authErr(err)
	}
	r.client = client
	syncerFactory := r.newSyncer
	if syncerFactory == nil {
		syncerFactory = func(client syncer.Client, s *store.Store, logger *slog.Logger) syncService {
			return syncer.New(client, s, logger)
		}
	}
	r.syncer = syncerFactory(r.client, r.store, r.logger)
	if configurable, ok := r.syncer.(attachmentTextConfigurer); ok {
		configurable.SetAttachmentTextEnabled(r.cfg.AttachmentTextEnabled())
	}
	return nil
}

func (r *runtime) autoUpdateShare(mode shareUpdateMode) error {
	if !r.cfg.ShareEnabled() || (mode == shareUpdateConfigured && !r.cfg.Share.AutoUpdate) {
		return nil
	}
	staleAfter, err := time.ParseDuration(r.cfg.Share.StaleAfter)
	if err != nil {
		return configErr(fmt.Errorf("invalid share.stale_after: %w", err))
	}
	if mode != shareUpdateForce && !share.NeedsImport(r.ctx, r.store, staleAfter) {
		return nil
	}
	opts, err := r.shareOptions()
	if err != nil {
		return err
	}
	r.setSyncLockPhase("share pull")
	r.logger.Info("share update pulling", "repo_path", opts.RepoPath, "remote", opts.Remote)
	if err := share.Pull(r.ctx, opts); err != nil {
		return err
	}
	r.setSyncLockPhase("share import")
	_, _, err = share.ImportIfChanged(r.ctx, r.store, opts)
	if errors.Is(err, share.ErrNoManifest) {
		return nil
	}
	return err
}

func (r *runtime) shareOptions() (share.Options, error) {
	repoPath, err := config.ExpandPath(r.cfg.Share.RepoPath)
	if err != nil {
		return share.Options{}, configErr(err)
	}
	return share.Options{
		RepoPath: repoPath,
		Remote:   r.cfg.Share.Remote,
		Branch:   r.cfg.Share.Branch,
		Progress: r.shareProgress,
	}, nil
}