package creator

import (
	"context"
	"crypto/rand"
	"database/sql"
	_ "embed"
	"encoding/hex"
	"encoding/json"
	"errors"
	"fmt"
	"sync"
	"time"

	"github.com/jackc/pgx/v5/pgconn"
	_ "github.com/jackc/pgx/v5/stdlib"
)

//go:embed migrations/017_creator.sql
var migration017 string

//go:embed migrations/018_collection_checkpoints.sql
var migration018 string

//go:embed migrations/019_metric_plans.sql
var migration019 string

//go:embed migrations/020_competitor_sync_leases.sql
var migration020 string

//go:embed migrations/021_work_sources.sql
var migration021 string

//go:embed migrations/022_collection_lease_tokens.sql
var migration022 string

//go:embed migrations/023_password_references.sql
var migration023 string

//go:embed migrations/024_event_processing_times.sql
var migration024 string

//go:embed migrations/025_competitor_sync_tokens.sql
var migration025 string

//go:embed migrations/026_event_message_text.sql
var migration026 string

//go:embed migrations/027_creator_listener_state.sql
var migration027 string

//go:embed migrations/028_creator_event_message_type.sql
var migration028 string

//go:embed migrations/029_creator_source_sync_lease.sql
var migration029 string

//go:embed migrations/030_creator_event_gateway_time.sql
var migration030 string

//go:embed migrations/031_xhs_raw_payloads.sql
var migration031 string

//go:embed migrations/032_douyin_release_remediation.sql
var migration032 string

//go:embed migrations/033_competitor_tags.sql
var migration033 string

// Creator migrations use their own history table. Phase-a and hub retain a
// shared schema_migration table for their schemas, but their numeric versions
// overlap with the creator migration files and must not suppress one another.
//
//go:embed migrations/034_competitor_tags_repair.sql
var migration034 string

//go:embed migrations/035_account_deletion.sql
var migration035 string

//go:embed migrations/036_competitor_unique_id.sql
var migration036 string

//go:embed migrations/037_competitor_share_jobs.sql
var migration037 string

type SecretReference struct {
	ID       string
	Provider string
}

type SecretBridge interface {
	Store(context.Context, SecretReference, string, string) error
	Delete(context.Context, SecretReference, string) error
}

type Store struct {
	db      *sql.DB
	secrets SecretBridge
	// Automatic writes for one execution account stay serialized while event
	// ingestion and unrelated accounts remain concurrent.
	automaticLocks sync.Map // map[string]*sync.Mutex
}

func Open(ctx context.Context, databaseURL string) (*Store, error) {
	db, err := sql.Open("pgx", databaseURL)
	if err != nil {
		return nil, errors.New("open creator database")
	}
	db.SetMaxOpenConns(10)
	db.SetMaxIdleConns(2)
	db.SetConnMaxIdleTime(5 * time.Minute)
	if err := db.PingContext(ctx); err != nil {
		_ = db.Close()
		return nil, errors.New("connect to creator database")
	}
	store := &Store{db: db}
	if err := store.migrate(ctx); err != nil {
		_ = db.Close()
		return nil, err
	}
	return store, nil
}

func (s *Store) Close() error { return s.db.Close() }

func (s *Store) Ping(ctx context.Context) error { return s.db.PingContext(ctx) }

func (s *Store) SetSecretBridge(bridge SecretBridge) { s.secrets = bridge }

func (s *Store) automaticExecutionLock(accountID string) *sync.Mutex {
	lock, _ := s.automaticLocks.LoadOrStore(accountID, &sync.Mutex{})
	return lock.(*sync.Mutex)
}

func (s *Store) acquireAutomaticExecutionLock(ctx context.Context, accountID string) (func(), error) {
	conn, err := s.db.Conn(ctx)
	if err != nil {
		return nil, databaseError(err)
	}
	if _, err := conn.ExecContext(ctx, `SELECT pg_advisory_lock(hashtextextended($1, 0))`, accountID); err != nil {
		_ = conn.Close()
		return nil, databaseError(err)
	}
	return func() { _ = conn.Close() }, nil
}

func (s *Store) migrate(ctx context.Context) error {
	tx, err := s.db.BeginTx(ctx, nil)
	if err != nil {
		return errors.New("begin creator schema migration")
	}
	defer tx.Rollback()
	if _, err := tx.ExecContext(ctx, `SELECT pg_advisory_xact_lock(1542738017)`); err != nil {
		return errors.New("lock creator schema migration")
	}
	if _, err := tx.ExecContext(ctx, `CREATE TABLE IF NOT EXISTS creator_schema_migration (version integer PRIMARY KEY, applied_at timestamptz NOT NULL DEFAULT now())`); err != nil {
		return errors.New("create creator schema migration table")
	}
	migrations := []struct {
		version int
		sql     string
	}{
		{version: 17, sql: migration017},
		{version: 18, sql: migration018},
		{version: 19, sql: migration019},
		{version: 20, sql: migration020},
		{version: 21, sql: migration021},
		{version: 22, sql: migration022},
		{version: 23, sql: migration023},
		{version: 24, sql: migration024},
		{version: 25, sql: migration025},
		{version: 26, sql: migration026},
		{version: 27, sql: migration027},
		{version: 28, sql: migration028},
		{version: 29, sql: migration029},
		{version: 30, sql: migration030},
		{version: 31, sql: migration031},
		{version: 32, sql: migration032},
		{version: 33, sql: migration033},
		{version: 34, sql: migration034},
		{version: 35, sql: migration035},
		{version: 36, sql: migration036},
		{version: 37, sql: migration037},
	}
	for _, migration := range migrations {
		var applied bool
		if err := tx.QueryRowContext(ctx, `SELECT EXISTS (SELECT 1 FROM creator_schema_migration WHERE version = $1)`, migration.version).Scan(&applied); err != nil {
			return errors.New("read creator schema migration state")
		}
		if applied {
			continue
		}
		if _, err := tx.ExecContext(ctx, migration.sql); err != nil {
			return fmt.Errorf("apply creator schema migration %d: %w", migration.version, err)
		}
		if _, err := tx.ExecContext(ctx, `INSERT INTO creator_schema_migration (version) VALUES ($1)`, migration.version); err != nil {
			return fmt.Errorf("record creator schema migration %d: %w", migration.version, err)
		}
	}
	if err := tx.Commit(); err != nil {
		return errors.New("commit creator schema migration")
	}
	return nil
}

func newID(prefix string) string {
	var bytes [12]byte
	if _, err := rand.Read(bytes[:]); err != nil {
		panic(fmt.Sprintf("generate creator id: %v", err))
	}
	return prefix + "-" + hex.EncodeToString(bytes[:])
}

func databaseError(err error) error {
	if err == nil {
		return nil
	}
	var pgErr *pgconn.PgError
	if errors.As(err, &pgErr) {
		switch pgErr.Code {
		case "23505":
			return ErrConflict
		case "23503", "23514", "22P02":
			return ErrInvalid
		}
	}
	return err
}

func rowError(err error) error {
	if errors.Is(err, sql.ErrNoRows) {
		return ErrNotFound
	}
	return databaseError(err)
}

func jsonText(value any) (string, error) {
	encoded, err := json.Marshal(value)
	if err != nil {
		return "", fmt.Errorf("encode creator json: %w", err)
	}
	return string(encoded), nil
}

func decodeStringList(encoded []byte) ([]string, error) {
	if len(encoded) == 0 {
		return []string{}, nil
	}
	var result []string
	if err := json.Unmarshal(encoded, &result); err != nil {
		return nil, fmt.Errorf("decode creator string list: %w", err)
	}
	if result == nil {
		result = []string{}
	}
	return result, nil
}

func nullableString(value string) any {
	if value == "" {
		return nil
	}
	return value
}

func nullableTime(value sql.NullTime) *time.Time {
	if !value.Valid {
		return nil
	}
	result := value.Time.UTC()
	return &result
}

func nullableInt64(value sql.NullInt64) *int64 {
	if !value.Valid {
		return nil
	}
	result := value.Int64
	return &result
}