package auth

import (
	"context"
	"encoding/json"
	"errors"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgxpool"

	"galo/internal/models"
)

var ErrNotFound = errors.New("not found")

type Store struct {
	pool *pgxpool.Pool
}

func NewStore(pool *pgxpool.Pool) *Store { return &Store{pool: pool} }

func (s *Store) CreateUser(ctx context.Context, u *models.User) error {
	_, err := s.pool.Exec(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 *Store) GetUserByEmail(ctx context.Context, email string) (*models.User, error) {
	return s.scanUser(s.pool.QueryRow(ctx,
		`SELECT id, email, password_hash, name, COALESCE(avatar_url, ''),
		        COALESCE(preferences, '{}'::jsonb)::text, created_at
		 FROM users WHERE lower(email) = lower($1)`, email))
}

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

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

func (s *Store) UpdatePreferences(ctx context.Context, userID string, raw []byte) error {
	tag, err := s.pool.Exec(ctx,
		`UPDATE users SET preferences = $2::jsonb WHERE id = $1`, userID, string(raw))
	if err != nil {
		return err
	}
	if tag.RowsAffected() == 0 {
		return ErrNotFound
	}
	return nil
}

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

func (s *Store) GetRefreshToken(ctx context.Context, hash string) (*models.RefreshToken, error) {
	var t models.RefreshToken
	err := s.pool.QueryRow(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, &t.ExpiresAt, &t.RevokedAt, &t.CreatedAt)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, ErrNotFound
		}
		return nil, err
	}
	return &t, nil
}

func (s *Store) RevokeRefreshToken(ctx context.Context, id string) error {
	_, err := s.pool.Exec(ctx,
		`UPDATE refresh_tokens SET revoked_at = now() WHERE id = $1 AND revoked_at IS NULL`, id)
	return err
}

func (s *Store) RevokeAllUserTokens(ctx context.Context, userID string) error {
	_, err := s.pool.Exec(ctx,
		`UPDATE refresh_tokens SET revoked_at = now() WHERE user_id = $1 AND revoked_at IS NULL`, userID)
	return err
}

func nullIfEmpty(s string) *string {
	if s == "" {
		return nil
	}
	return &s
}