package notifications

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

	"shared-album/internal/models"
	"shared-album/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) Create(ctx context.Context, n *models.Notification) error {
	payload, err := json.Marshal(n.PayloadJSON)
	if err != nil {
		return err
	}
	var createdAt string
	err = s.db.QueryRowContext(ctx,
		`INSERT INTO notifications (id, user_id, type, payload_json)
		 VALUES ($1, $2, $3, $4)
		 RETURNING created_at`,
		n.ID, n.UserID, n.Type, string(payload)).Scan(&createdAt)
	if err != nil {
		return err
	}
	n.CreatedAt = sqliteutil.ParseTime(createdAt)
	return nil
}

func (s *SQLiteStore) List(ctx context.Context, userID string, limit int) ([]models.Notification, error) {
	if limit <= 0 || limit > 200 {
		limit = 100
	}
	rows, err := s.db.QueryContext(ctx,
		`SELECT id, user_id, type, payload_json, read_at, created_at
		 FROM notifications
		 WHERE user_id = $1
		 ORDER BY created_at DESC
		 LIMIT $2`, userID, limit)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	out := []models.Notification{}
	for rows.Next() {
		var n models.Notification
		var payload, createdAt string
		var readAt sql.NullString
		if err := rows.Scan(&n.ID, &n.UserID, &n.Type, &payload, &readAt, &createdAt); err != nil {
			return nil, err
		}
		_ = json.Unmarshal([]byte(payload), &n.PayloadJSON)
		n.ReadAt = sqliteutil.ParseNullTime(readAt)
		n.CreatedAt = sqliteutil.ParseTime(createdAt)
		out = append(out, n)
	}
	return out, rows.Err()
}

func (s *SQLiteStore) MarkRead(ctx context.Context, id, userID string) error {
	res, err := s.db.ExecContext(ctx,
		`UPDATE notifications SET read_at = $3 WHERE id = $1 AND user_id = $2 AND read_at IS NULL`,
		id, userID, sqliteutil.FormatTime(time.Now()))
	if err != nil {
		return err
	}
	if n, _ := res.RowsAffected(); n == 0 {
		var exists int
		err := s.db.QueryRowContext(ctx,
			`SELECT 1 FROM notifications WHERE id = $1 AND user_id = $2`, id, userID).Scan(&exists)
		if err != nil {
			if errors.Is(err, sql.ErrNoRows) {
				return ErrNotFound
			}
			return err
		}
	}
	return nil
}