package builtin

import (
	"bytes"
	"crypto/md5"
	"encoding/csv"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"math"
	"math/rand"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"time"

	"gopkg.in/yaml.v3"

	"github.com/rs/zerolog/log"
)

var Functions = map[string]interface{}{
	"get_timestamp":     getTimestamp,    // call without arguments
	"sleep":             sleep,           // call with one argument
	"gen_random_string": genRandomString, // call with one argument
	"max":               math.Max,        // call with two arguments
	"md5":               MD5,             // call with one argument
	"parameterize":      loadFromCSV,
	"P":                 loadFromCSV,
}

func init() {
	rand.Seed(time.Now().UnixNano())
}

func getTimestamp() int64 {
	return time.Now().UnixNano() / int64(time.Millisecond)
}

func sleep(nSecs int) {
	time.Sleep(time.Duration(nSecs) * time.Second)
}

const letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890"

func genRandomString(n int) string {
	lettersLen := len(letters)
	b := make([]byte, n)
	for i := range b {
		b[i] = letters[rand.Intn(lettersLen)]
	}
	return string(b)
}

func MD5(str string) string {
	hasher := md5.New()
	hasher.Write([]byte(str))
	return hex.EncodeToString(hasher.Sum(nil))
}

func loadFromCSV(path string) []map[string]interface{} {
	path, err := filepath.Abs(path)
	if err != nil {
		log.Error().Str("path", path).Err(err).Msg("convert absolute path failed")
		panic(err)
	}
	log.Info().Str("path", path).Msg("load csv file")

	file, err := os.ReadFile(path)
	if err != nil {
		log.Error().Err(err).Msg("load csv file failed")
		panic(err)
	}
	r := csv.NewReader(strings.NewReader(string(file)))
	content, err := r.ReadAll()
	if err != nil {
		log.Error().Err(err).Msg("parse csv file failed")
		panic(err)
	}
	var result []map[string]interface{}
	for i := 1; i < len(content); i++ {
		row := make(map[string]interface{})
		for j := 0; j < len(content[i]); j++ {
			row[content[0][j]] = content[i][j]
		}
		result = append(result, row)
	}
	return result
}

func Dump2JSON(data interface{}, path string) error {
	path, err := filepath.Abs(path)
	if err != nil {
		log.Error().Err(err).Msg("convert absolute path failed")
		return err
	}
	log.Info().Str("path", path).Msg("dump data to json")
	file, _ := json.MarshalIndent(data, "", "\t")
	err = os.WriteFile(path, file, 0644)
	if err != nil {
		log.Error().Err(err).Msg("dump json path failed")
		return err
	}
	return nil
}

func Dump2YAML(data interface{}, path string) error {
	path, err := filepath.Abs(path)
	if err != nil {
		log.Error().Err(err).Msg("convert absolute path failed")
		return err
	}
	log.Info().Str("path", path).Msg("dump data to yaml")

	// init yaml encoder
	buffer := new(bytes.Buffer)
	encoder := yaml.NewEncoder(buffer)
	encoder.SetIndent(4)

	// encode
	err = encoder.Encode(data)
	if err != nil {
		return err
	}

	err = os.WriteFile(path, buffer.Bytes(), 0644)
	if err != nil {
		log.Error().Err(err).Msg("dump yaml path failed")
		return err
	}
	return nil
}

func FormatResponse(raw interface{}) interface{} {
	formattedResponse := make(map[string]interface{})
	for key, value := range raw.(map[string]interface{}) {
		// convert value to json
		if key == "body" {
			b, _ := json.MarshalIndent(&value, "", "\t")
			value = string(b)
		}
		formattedResponse[key] = value
	}
	return formattedResponse
}

func ExecCommand(cmd *exec.Cmd, cwd string) error {
	log.Info().Str("cmd", cmd.String()).Str("cwd", cwd).Msg("exec command")
	cmd.Dir = cwd
	output, err := cmd.CombinedOutput()
	out := strings.TrimSpace(string(output))
	if err != nil {
		log.Error().Err(err).Str("output", out).Msg("exec command failed")
	} else if len(out) != 0 {
		log.Info().Str("output", out).Msg("exec command success")
	}
	return err
}

func CreateFolder(folderPath string) error {
	log.Info().Str("path", folderPath).Msg("create folder")
	err := os.MkdirAll(folderPath, os.ModePerm)
	if err != nil {
		log.Error().Err(err).Msg("create folder failed")
		return err
	}
	return nil
}

func CreateFile(filePath string, data string) error {
	log.Info().Str("path", filePath).Msg("create file")
	err := os.WriteFile(filePath, []byte(data), 0o644)
	if err != nil {
		log.Error().Err(err).Msg("create file failed")
		return err
	}
	return nil
}

// isFilePathExists returns true if path exists, whether path is file or dir
func isPathExists(path string) bool {
	if _, err := os.Stat(path); os.IsNotExist(err) {
		return false
	}
	return true
}

// isFilePathExists returns true if path exists and path is file
func isFilePathExists(path string) bool {
	info, err := os.Stat(path)
	if err != nil {
		// path not exists
		return false
	}

	// path exists
	if info.IsDir() {
		// path is dir, not file
		return false
	}
	return true
}

func EnsureFolderExists(folderPath string) error {
	if !isPathExists(folderPath) {
		err := CreateFolder(folderPath)
		return err
	} else if isFilePathExists(folderPath) {
		return fmt.Errorf("path %v should be directory", folderPath)
	}
	return nil
}