package auth

import (
	"context"
	"database/sql"
	"encoding/json"
	"errors"
	"time"

	"galo/internal/models"
	"galo/internal/sqliteutil"
)

// SQLiteStore is the SQLite implementation of Repository.
type SQLiteStore struct {
	db *sql.DB
}

func NewSQLiteStore(db *sql.DB) *SQLiteStore { return &SQLiteStore{db: db} }

func (s *SQLiteStore) CreateUser(ctx context.Context, u *models.User) error {
	_, err := s.db.ExecContext(ctx,
		`INSERT INTO users (id, email, password_hash, name, avatar_url)
		 VALUES ($1, $2, $3, $4, $5)`,
		u.ID, u.Email, u.PasswordHash, u.Name, nullIfEmpty(u.AvatarURL))
	return err
}

func (s *SQLiteStore) GetUserByEmail(ctx context.Context, email string) (*models.User, error) {
	return s.scanUser(s.db.QueryRowContext(ctx,
		`SELECT id, email, password_hash, name, COALESCE(avatar_url, ''),
		        COALESCE(preferences, '{}'), created_at
		 FROM users WHERE lower(email) = lower($1)`, email))
}

func (s *SQLiteStore) GetUserByID(ctx context.Context, id string) (*models.User, error) {
	return s.scanUser(s.db.QueryRowContext(ctx,
		`SELECT id, email, password_hash, name, COALESCE(avatar_url, ''),
		        COALESCE(preferences, '{}'), created_at
		 FROM users WHERE id = $1`, id))
}

func (s *SQLiteStore) scanUser(row *sql.Row) (*models.User, error) {
	var u models.User
	var prefs, createdAt string
	if err := row.Scan(&u.ID, &u.Email, &u.PasswordHash, &u.Name, &u.AvatarURL, &prefs, &createdAt); err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return nil, ErrNotFound
		}
		return nil, err
	}
	u.CreatedAt = sqliteutil.ParseTime(createdAt)
	if prefs != "" && prefs != "null" {
		_ = json.Unmarshal([]byte(prefs), &u.Preferences)
	}
	return &u, nil
}

func (s *SQLiteStore) UpdatePreferences(ctx context.Context, userID string, raw []byte) error {
	res, err := s.db.ExecContext(ctx,
		`UPDATE users SET preferences = $2 WHERE id = $1`, userID, string(raw))
	if err != nil {
		return err
	}
	if n, _ := res.RowsAffected(); n == 0 {
		return ErrNotFound
	}
	return nil
}

func (s *SQLiteStore) CreateRefreshToken(ctx context.Context, t *models.RefreshToken) error {
	_, err := s.db.ExecContext(ctx,
		`INSERT INTO refresh_tokens (id, user_id, token_hash, expires_at)
		 VALUES ($1, $2, $3, $4)`,
		t.ID, t.UserID, t.TokenHash, sqliteutil.FormatTime(t.ExpiresAt))
	return err
}

func (s *SQLiteStore) GetRefreshToken(ctx context.Context, hash string) (*models.RefreshToken, error) {
	var t models.RefreshToken
	var expiresAt, createdAt string
	var revokedAt sql.NullString
	err := s.db.QueryRowContext(ctx,
		`SELECT id, user_id, token_hash, expires_at, revoked_at, created_at
		 FROM refresh_tokens WHERE token_hash = $1`, hash).
		Scan(&t.ID, &t.UserID, &t.TokenHash, &expiresAt, &revokedAt, &createdAt)
	if err != nil {
		if errors.Is(err, sql.ErrNoRows) {
			return nil, ErrNotFound
		}
		return nil, err
	}
	t.ExpiresAt = sqliteutil.ParseTime(expiresAt)
	t.CreatedAt = sqliteutil.ParseTime(createdAt)
	t.RevokedAt = sqliteutil.ParseNullTime(revokedAt)
	return &t, nil
}

func (s *SQLiteStore) RevokeRefreshToken(ctx context.Context, id string) error {
	_, err := s.db.ExecContext(ctx,
		`UPDATE refresh_tokens SET revoked_at = $2 WHERE id = $1 AND revoked_at IS NULL`,
		id, sqliteutil.FormatTime(time.Now()))
	return err
}

func (s *SQLiteStore) RevokeAllUserTokens(ctx context.Context, userID string) error {
	_, err := s.db.ExecContext(ctx,
		`UPDATE refresh_tokens SET revoked_at = $2 WHERE user_id = $1 AND revoked_at IS NULL`,
		userID, sqliteutil.FormatTime(time.Now()))
	return err
}