package main

import (
	"database/sql"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"strings"

	_ "modernc.org/sqlite"
)

func main() {
	if len(os.Args) < 2 {
		log.Fatal("Usage: go run cmd/migrate/main.go [up|down]")
	}

	command := os.Args[1]
	dbPath := "./messenger.db"

	db, err := sql.Open("sqlite", dbPath)
	if err != nil {
		log.Fatal(err)
	}
	defer db.Close()

	switch command {
	case "up":
		if err := migrateUp(db); err != nil {
			log.Fatal(err)
		}
		fmt.Println("Migrations completed successfully")
	case "down":
		if err := migrateDown(db); err != nil {
			log.Fatal(err)
		}
		fmt.Println("Rollback completed successfully")
	default:
		log.Fatal("Unknown command. Use 'up' or 'down'")
	}
}

func migrateUp(db *sql.DB) error {
	files, err := filepath.Glob("migrations/*.up.sql")
	if err != nil {
		return err
	}

	for _, file := range files {
		fmt.Printf("Applying migration: %s\n", file)
		
		content, err := ioutil.ReadFile(file)
		if err != nil {
			return err
		}

		// Разделяем по ";"
		statements := strings.Split(string(content), ";")
		
		for _, stmt := range statements {
			stmt = strings.TrimSpace(stmt)
			if stmt == "" {
				continue
			}
			
			if _, err := db.Exec(stmt); err != nil {
				return fmt.Errorf("failed to execute %s: %v\nStatement: %s", file, err, stmt)
			}
		}
	}

	return nil
}

func migrateDown(db *sql.DB) error {
	files, err := filepath.Glob("migrations/*.down.sql")
	if err != nil {
		return err
	}

	for _, file := range files {
		fmt.Printf("Rolling back: %s\n", file)
		
		content, err := ioutil.ReadFile(file)
		if err != nil {
			return err
		}

		statements := strings.Split(string(content), ";")
		
		for _, stmt := range statements {
			stmt = strings.TrimSpace(stmt)
			if stmt == "" {
				continue
			}
			
			if _, err := db.Exec(stmt); err != nil {
				return fmt.Errorf("failed to execute %s: %v", file, err)
			}
		}
	}

	return nil
}