package main

import (
	"fmt"
	"io"
	"log"
	"os"
	"path/filepath"
	"strings"
)

func generateEnv(yamlFile string) {
	config := loadConfig(yamlFile)

	// Check that all local directories exist
	for _, logEntry := range config.Logs {
		if _, err := os.Stat(logEntry.LocalDirectory); os.IsNotExist(err) {
			log.Fatalf("User is required to create %s", logEntry.LocalDirectory)
		}
	}

	// Generate .env file for each log
	for _, logEntry := range config.Logs {
		envPath := filepath.Join(logEntry.LocalDirectory, ".env")

		// Create combined roots.pem file
		rootsPemPath := filepath.Join(logEntry.LocalDirectory, "roots.pem")
		err := createCombinedRootsPem(config.Roots, logEntry.ExtraRoots, rootsPemPath)
		if err != nil {
			log.Fatalf("Failed to create %s: %v", rootsPemPath, err)
		}
		fmt.Printf("Generated %s\n", rootsPemPath)

		// Build TESSERACT_ARGS string
		args := []string{
			fmt.Sprintf("--private_key=%s", logEntry.Secret),
			fmt.Sprintf("--origin=%s.log.ct.ipng.ch", logEntry.ShortName),
			fmt.Sprintf("--storage_dir=%s", logEntry.LocalDirectory),
			fmt.Sprintf("--roots_pem_file=%s", rootsPemPath),
		}

		tesseractArgs := strings.Join(args, " ")
		envContent := fmt.Sprintf("TESSERACT_ARGS=\"%s\"\n", tesseractArgs)

		err = os.WriteFile(envPath, []byte(envContent), 0644)
		if err != nil {
			log.Fatalf("Failed to write %s: %v", envPath, err)
		}

		fmt.Printf("Generated %s\n", envPath)
	}
}

func createCombinedRootsPem(rootsFile, extraRootsFile, outputPath string) error {
	// Create output file
	outputFile, err := os.Create(outputPath)
	if err != nil {
		return fmt.Errorf("failed to create output file: %v", err)
	}
	defer outputFile.Close()

	// Copy main roots file
	if rootsFile != "" {
		rootsData, err := os.Open(rootsFile)
		if err != nil {
			return fmt.Errorf("failed to open roots file %s: %v", rootsFile, err)
		}
		defer rootsData.Close()

		_, err = io.Copy(outputFile, rootsData)
		if err != nil {
			return fmt.Errorf("failed to copy roots file: %v", err)
		}
	}

	// Append extra roots file if it exists
	if extraRootsFile != "" {
		extraRootsData, err := os.Open(extraRootsFile)
		if err != nil {
			return fmt.Errorf("failed to open extra roots file %s: %v", extraRootsFile, err)
		}
		defer extraRootsData.Close()

		_, err = io.Copy(outputFile, extraRootsData)
		if err != nil {
			return fmt.Errorf("failed to copy extra roots file: %v", err)
		}
	}

	return nil
}