package pds

import (
	"context"
	"fmt"
	"log/slog"
	"os"
	"path/filepath"
	"strings"

	"atcr.io/pkg/atproto"
	"atcr.io/pkg/auth/oauth"
	"github.com/bluesky-social/indigo/atproto/atcrypto"
	"github.com/bluesky-social/indigo/carstore"
	lexutil "github.com/bluesky-social/indigo/lex/util"
	"github.com/bluesky-social/indigo/models"
	"github.com/bluesky-social/indigo/repo"
	"github.com/distribution/distribution/v3/registry/storage/driver"
	"github.com/ipfs/go-cid"
)

// init registers our custom ATProto types with indigo's lexutil type registry
// This allows repomgr.GetRecord to automatically unmarshal our types
func init() {
	// Register captain, crew, tangled profile, and layer record types
	// These must match the $type field in the records
	lexutil.RegisterType(atproto.CaptainCollection, &atproto.CaptainRecord{})
	lexutil.RegisterType(atproto.CrewCollection, &atproto.CrewRecord{})
	lexutil.RegisterType(atproto.LayerCollection, &atproto.LayerRecord{})
	lexutil.RegisterType(atproto.TangledProfileCollection, &atproto.TangledProfileRecord{})
}

// HoldPDS is a minimal ATProto PDS implementation for a hold service
type HoldPDS struct {
	did                string
	PublicURL          string
	carstore           carstore.CarStore
	repomgr            *RepoManager
	dbPath             string
	uid                models.Uid
	signingKey         *atcrypto.PrivateKeyK256
	enableBlueskyPosts bool
}

// NewHoldPDS creates or opens a hold PDS with SQLite carstore
func NewHoldPDS(ctx context.Context, did, publicURL, dbPath, keyPath string, enableBlueskyPosts bool) (*HoldPDS, error) {
	// Generate or load signing key
	signingKey, err := oauth.GenerateOrLoadPDSKey(keyPath)
	if err != nil {
		return nil, fmt.Errorf("failed to initialize signing key: %w", err)
	}

	// Create SQLite-backed carstore
	var sqlStore *carstore.SQLiteStore

	if dbPath == ":memory:" {
		// In-memory mode for tests: create carstore manually and open with :memory:
		sqlStore = new(carstore.SQLiteStore)
		if err := sqlStore.Open(":memory:"); err != nil {
			return nil, fmt.Errorf("failed to open in-memory sqlite store: %w", err)
		}
	} else {
		// File mode for production: create directory and use NewSqliteStore
		dir := filepath.Dir(dbPath)
		if err := os.MkdirAll(dir, 0755); err != nil {
			return nil, fmt.Errorf("failed to create database directory: %w", err)
		}

		// dbPath is the directory, carstore creates and opens db.sqlite3 inside it
		sqlStore, err = carstore.NewSqliteStore(dbPath)
		if err != nil {
			return nil, fmt.Errorf("failed to create sqlite store: %w", err)
		}
	}

	// Use SQLiteStore directly, not the CarStore() wrapper
	// The wrapper has a bug where GetUserRepoHead checks CarShard.ID which SQLite doesn't populate
	cs := sqlStore

	// For a single-user hold, we use a fixed UID (1)
	uid := models.Uid(1)

	// Create KeyManager wrapper for our signing key
	kmgr := NewHoldKeyManager(signingKey)

	// Create RepoManager - it will handle all session/repo lifecycle
	rm := NewRepoManager(cs, kmgr)

	// Check if repo already exists, if not create initial commit
	head, err := cs.GetUserRepoHead(ctx, uid)
	hasValidRepo := (err == nil && head.Defined())

	if !hasValidRepo {
		// Initialize empty repo with first commit
		// RepoManager requires at least one commit to exist
		// We'll create this by doing a dummy operation in Bootstrap
		slog.Info("New hold repo - will be initialized in Bootstrap")
	}

	return &HoldPDS{
		did:                did,
		PublicURL:          publicURL,
		carstore:           cs,
		repomgr:            rm,
		dbPath:             dbPath,
		uid:                uid,
		signingKey:         signingKey,
		enableBlueskyPosts: enableBlueskyPosts,
	}, nil
}

// DID returns the hold's DID
func (p *HoldPDS) DID() string {
	return p.did
}

// SigningKey returns the hold's signing key
func (p *HoldPDS) SigningKey() *atcrypto.PrivateKeyK256 {
	return p.signingKey
}

// RepomgrRef returns a reference to the RepoManager for event handler setup
func (p *HoldPDS) RepomgrRef() *RepoManager {
	return p.repomgr
}

// Bootstrap initializes the hold with the captain record, owner as first crew member, and profile
func (p *HoldPDS) Bootstrap(ctx context.Context, storageDriver driver.StorageDriver, ownerDID string, public bool, allowAllCrew bool, avatarURL string) error {
	if ownerDID == "" {
		return nil
	}

	// Check if captain record already exists (idempotent bootstrap)
	_, _, err := p.GetCaptainRecord(ctx)
	captainExists := (err == nil)

	if captainExists {
		// Captain record exists, skip captain/crew setup but still create profile if needed
		slog.Info("Captain record exists, skipping captain/crew setup")
	} else {
		slog.Info("Bootstrapping hold PDS", "owner", ownerDID)
	}

	if !captainExists {

		// Initialize repo if it doesn't exist yet
		// Check if repo exists by trying to get the head
		head, err := p.carstore.GetUserRepoHead(ctx, p.uid)
		if err != nil || !head.Defined() {
			// Repo doesn't exist, initialize it
			// InitNewActor creates an empty repo with initial commit
			err = p.repomgr.InitNewActor(ctx, p.uid, "", p.did, "", "", "")
			if err != nil {
				return fmt.Errorf("failed to initialize repo: %w", err)
			}
			slog.Info("Initialized empty repo")
		}

		// Create captain record (hold ownership and settings)
		_, err = p.CreateCaptainRecord(ctx, ownerDID, public, allowAllCrew, p.enableBlueskyPosts)
		if err != nil {
			return fmt.Errorf("failed to create captain record: %w", err)
		}

		slog.Info("Created captain record",
			"public", public,
			"allowAllCrew", allowAllCrew,
			"enableBlueskyPosts", p.enableBlueskyPosts)

		// Add hold owner as first crew member with admin role
		_, err = p.AddCrewMember(ctx, ownerDID, "admin", []string{"blob:read", "blob:write", "crew:admin"})
		if err != nil {
			return fmt.Errorf("failed to add owner as crew member: %w", err)
		}

		slog.Info("Added owner as hold admin", "did", ownerDID)
	} else {
		// Captain record exists, check if we need to sync settings from env vars
		_, existingCaptain, err := p.GetCaptainRecord(ctx)
		if err == nil {
			// Check if any settings need updating
			needsUpdate := existingCaptain.Public != public ||
				existingCaptain.AllowAllCrew != allowAllCrew ||
				existingCaptain.EnableBlueskyPosts != p.enableBlueskyPosts

			if needsUpdate {
				// Update captain record to match env vars
				_, err = p.UpdateCaptainRecord(ctx, public, allowAllCrew, p.enableBlueskyPosts)
				if err != nil {
					return fmt.Errorf("failed to update captain record: %w", err)
				}
				slog.Info("Synced captain record with env vars",
					"public", public,
					"allowAllCrew", allowAllCrew,
					"enableBlueskyPosts", p.enableBlueskyPosts)
			}
		}
	}

	// Create Bluesky profile record (idempotent - check if exists first)
	// This runs even if captain exists (for existing holds being upgraded)
	// Skip if no storage driver (e.g., in tests)
	if storageDriver != nil {
		_, _, err = p.GetProfileRecord(ctx)
		if err != nil {
			// Bluesky profile doesn't exist, create it
			displayName := "Cargo Hold"
			description := "ahoy from the cargo hold"

			_, err = p.CreateProfileRecord(ctx, storageDriver, displayName, description, avatarURL)
			if err != nil {
				return fmt.Errorf("failed to create bluesky profile record: %w", err)
			}
			slog.Info("Created Bluesky profile record", "displayName", displayName)
		} else {
			slog.Info("Bluesky profile record already exists, skipping")
		}
	}

	return nil
}

// ListCollections returns all collections present in the hold's repository
func (p *HoldPDS) ListCollections(ctx context.Context) ([]string, error) {
	session, err := p.carstore.ReadOnlySession(p.uid)
	if err != nil {
		return nil, fmt.Errorf("failed to create read-only session: %w", err)
	}

	head, err := p.carstore.GetUserRepoHead(ctx, p.uid)
	if err != nil {
		return nil, fmt.Errorf("failed to get repo head: %w", err)
	}

	if !head.Defined() {
		// Empty repo, no collections
		return []string{}, nil
	}

	r, err := repo.OpenRepo(ctx, session, head)
	if err != nil {
		return nil, fmt.Errorf("failed to open repo: %w", err)
	}

	collections := make(map[string]bool)

	// Walk all records in the repo to discover collections
	err = r.ForEach(ctx, "", func(k string, v cid.Cid) error {
		// k is like "io.atcr.hold.captain/self" or "io.atcr.hold.crew/3m3by7msdln22"
		parts := strings.Split(k, "/")
		if len(parts) >= 1 {
			collections[parts[0]] = true
		}
		return nil
	})

	if err != nil {
		return nil, fmt.Errorf("failed to enumerate collections: %w", err)
	}

	// Convert map to sorted slice
	result := make([]string, 0, len(collections))
	for collection := range collections {
		result = append(result, collection)
	}

	return result, nil
}

// Close closes the carstore
func (p *HoldPDS) Close() error {
	// TODO: Close session properly
	return nil
}