package database

import (
	"database/sql"
	"fmt"
	"log"
	"os"

	_ "github.com/lib/pq"
)

var DB *sql.DB

func InitDB() {
	var err error
	host := os.Getenv("DB_HOST")
	if host == "" {
		log.Fatal("DB_HOST environment variable not set")
	}
	user := os.Getenv("DB_USER")
	if user == "" {
		log.Fatal("DB_USER environment variable not set")
	}
	password := os.Getenv("DB_PASSWORD")
	if password == "" {
		log.Fatal("DB_PASSWORD environment variable not set")
	}
	dbname := os.Getenv("DB_NAME")
	if dbname == "" {
		log.Fatal("DB_NAME environment variable not set")
	}
	port := os.Getenv("DB_PORT")
	if port == "" {
		port = "5432"
	}

	sslmode := os.Getenv("DB_SSLMODE")
	if sslmode == "" {
		sslmode = "require" // Default to require for production security
	}

	connStr := fmt.Sprintf("host=%s port=%s user=%s password=%s dbname=%s sslmode=%s",
		host, port, user, password, dbname, sslmode)

	DB, err = sql.Open("postgres", connStr)
	if err != nil {
		log.Fatalf("Error opening database: %v", err)
	}

	if err = DB.Ping(); err != nil {
		log.Fatalf("Error connecting to database: %v", err)
	}

	log.Println("Successfully connected to the database")
}

func RunMigrations() {
	files, err := os.ReadDir("migrations")
	if err != nil {
		// Try fallback to relative path if running from cmd/api
		files, err = os.ReadDir("../../migrations")
		if err != nil {
			log.Printf("Warning: Could not list migrations directory: %v", err)
			return
		}
	}

	// Sort files by name to ensure order (001, 002, ...)
	// ReadDir returns sorted by name automatically, but let's be safe if logic changes?
	// Actually ReadDir result is sorted by filename.

	for _, file := range files {
		if file.IsDir() {
			continue
		}

		log.Printf("Running migration: %s", file.Name())
		content, err := os.ReadFile("migrations/" + file.Name())
		if err != nil {
			// Try fallback
			content, err = os.ReadFile("../../migrations/" + file.Name())
			if err != nil {
				log.Fatalf("Error reading migration file %s: %v", file.Name(), err)
			}
		}

		_, err = DB.Exec(string(content))
		if err != nil {
			// Log warning but don't crash on "already exists" errors if possible,
			// but pure SQL Exec might fail hard.
			// Given the SQL files use IF NOT EXISTS, we should be fine.
			// If one fails, it might be syntax.
			log.Printf("Error running migration %s: %v", file.Name(), err)
			// Continue or Fail? User wants robustness. Let's Warn and continue for now to avoid single failure blocking all
		} else {
			log.Printf("Migration %s executed successfully", file.Name())
		}
	}
	log.Println("All migrations processed")
}