package database

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

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

type DB struct {
	Pool *pgxpool.Pool
}

func Connect(ctx context.Context, databaseURL string) (*DB, error) {
	cfg, err := pgxpool.ParseConfig(databaseURL)
	if err != nil {
		return nil, fmt.Errorf("parse database url: %w", err)
	}

	cfg.MaxConns = 10
	cfg.MinConns = 1
	cfg.MaxConnLifetime = time.Hour
	cfg.MaxConnIdleTime = 30 * time.Minute

	pool, err := pgxpool.NewWithConfig(ctx, cfg)
	if err != nil {
		return nil, fmt.Errorf("create database pool: %w", err)
	}

	if err := pool.Ping(ctx); err != nil {
		pool.Close()
		return nil, fmt.Errorf("ping database: %w", err)
	}

	return &DB{Pool: pool}, nil
}

func (db *DB) Close() {
	if db != nil && db.Pool != nil {
		db.Pool.Close()
	}
}

func (db *DB) Migrate(ctx context.Context, logger *slog.Logger, migrationsDir string) error {
	files, err := filepath.Glob(filepath.Join(migrationsDir, "*.sql"))
	if err != nil {
		return fmt.Errorf("list migrations: %w", err)
	}

	sort.Strings(files)

	for _, file := range files {
		sql, err := os.ReadFile(file)
		if err != nil {
			return fmt.Errorf("read migration %s: %w", file, err)
		}

		statement := strings.TrimSpace(string(sql))
		if statement == "" {
			continue
		}

		if _, err := db.Pool.Exec(ctx, statement); err != nil {
			return fmt.Errorf("run migration %s: %w", file, err)
		}

		logger.Info("migration applied", "file", filepath.Base(file))
	}

	return nil
}