package config

import (
	"encoding/json"
	"fmt"
	"github.com/go-playground/validator/v10"
	"io"
	"os"
	"path/filepath"

	"github.com/pelletier/go-toml/v2"
	"gopkg.in/yaml.v3"
)

type FileType string

const (
	YAML FileType = "yaml"
	TOML FileType = "toml"
	JSON FileType = "json"
)

// getFileType returns the file type based on the file extension.
func getFileType(path string) (FileType, error) {
	// Get the file extension
	ext := filepath.Ext(path)

	switch ext {
	case ".yaml", ".yml":
		return YAML, nil
	case ".toml":
		return TOML, nil
	case ".json":
		return JSON, nil
	default:
		return "", fmt.Errorf("unsupported file type: %s", ext)
	}
}

func ParseConfig(path string) (Config, error) {
	fileType, err := getFileType(path)
	if err != nil {
		return Config{}, err
	}

	file, err := os.Open(path)
	if err != nil {
		return Config{}, err
	}
	defer file.Close()

	data, err := io.ReadAll(file)

	var config Config

	switch fileType {
	case YAML:
		config, err = parseYAML(data)
	case TOML:
		config, err = parseTOML(data)
	case JSON:
		config, err = parseJSON(data)
	default:
		return Config{}, fmt.Errorf("unsupported file type: %s", fileType)
	}

	if err != nil {
		return Config{}, err
	}

	validate := validator.New(validator.WithRequiredStructEnabled())
	err = validate.Struct(config)

	if err != nil {
		return Config{}, err
	}

	return config, nil
}

func parseTOML(data []byte) (Config, error) {
	var appConfig Config
	err := toml.Unmarshal(data, &appConfig)
	if err != nil {
		return Config{}, err
	}
	return appConfig, nil
}

func parseYAML(data []byte) (Config, error) {
	var appConfig Config
	err := yaml.Unmarshal(data, &appConfig)
	if err != nil {
		return Config{}, err
	}
	return appConfig, nil
}

func parseJSON(data []byte) (Config, error) {
	var appConfig Config
	err := json.Unmarshal(data, &appConfig)
	if err != nil {
		return Config{}, err
	}
	return appConfig, nil
}