package internal

import (
	"bufio"
	"fmt"
	"oc-k8s/utils"
	"os"
	"regexp"
	"strings"
)

func Help_Values() {
	fmt.Println(`
Values commands: oc-k8s <action> values
  create   - Create a new values release yaml
  help     - Show this help message

Usage:
  oc-k8s create values [release] [env_folder] [env_file] 
    release - Release values name (required)
	env_folder - Helm config folder (optionnal, default: .)
    env_file - env to map (optionnal)
  oc-k8s help values `)
}

var varPattern = regexp.MustCompile(`\$\{([A-Za-z_][A-Za-z0-9_]*)[:-]([^}]+)\}`)

func Create_Values(args ...string) error {
	folder := "."
	release := "dev"
	conf := ""

	if len(args) > 0 {
		release = args[0]
	}
	if len(args) > 1 {
		folder = args[1]
	}
	if len(args) > 2 {
		conf = args[2]
	}
	return generateConfig(conf, release, folder)
}

func generateConfig(confFile string, release string, output_folder string) error {
	// Load env file if provided
	var err error
	confs := map[string]string{}
	if confFile != "" {
		if confs, err = loadEnvFile(confFile); err != nil {
			return err
		}
	} else {
		confFile = "no configuration file"
	}
	// Read template
	content, err := utils.ReadFS("assets/values.yaml.template")
	if err != nil {
		return err
	}

	rendered := renderTemplate(string(content), confs)

	// Ensure output directory exists
	if err := os.MkdirAll(output_folder, 0755); err != nil {
		return err
	}

	// Write output
	if err := os.WriteFile(output_folder+"/"+release+"-values.yaml", []byte(rendered), 0644); err != nil {
		return err
	}
	fmt.Printf("Rendered %s from %s using %s\n", output_folder+"/"+release+"-values.yaml", "assets/values.yaml.template", confFile)
	return nil
}

func loadEnvFile(path string) (map[string]string, error) {
	envs := map[string]string{}
	file, err := os.Open(path)
	if err != nil {
		return envs, err
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		line := strings.TrimSpace(scanner.Text())

		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}

		parts := strings.SplitN(line, "=", 2)
		if len(parts) != 2 {
			continue
		}

		key := strings.TrimSpace(parts[0])
		val := strings.Trim(strings.TrimSpace(parts[1]), `"'`)

		envs[key] = val
	}
	return envs, scanner.Err()
}

func renderTemplate(input string, envs map[string]string) string {
	return varPattern.ReplaceAllStringFunc(input, func(match string) string {
		sub := varPattern.FindStringSubmatch(match)
		varName := sub[1]
		defaultVal := sub[2][1:]

		if val, ok := envs[varName]; ok && val != "" {
			return val
		}
		return defaultVal
	})
}