package form

import (
	"bytes"
	"encoding/json"
	"html"
	"io"
	"io/ioutil"
	"net/http"
	"regexp"
	"strconv"
	"strings"
	"time"
)

type readCloser struct {
	io.Reader
}

func (rc readCloser) Close() error {
	return nil
}

func GetAll(r *http.Request, k string) []string {
	r.ParseForm()
	v, _ := r.Form[k]
	return v
}

func Get(r *http.Request, k string) string {
	s := r.FormValue(k)
	if s == "" {
		b, _ := ioutil.ReadAll(r.Body)
		var m map[string]json.RawMessage
		if err := json.Unmarshal(b, &m); err != nil {
			return ""
		}
		v, _ := m[k]
		s = strings.TrimPrefix(strings.TrimSuffix(string(v), `"`), `"`)
		r.Body = readCloser{bytes.NewReader(b)}
	}
	s = html.UnescapeString(s)
	s = strings.ReplaceAll(s, "\r", "")
	return s
}

func ToInt(s string) int {
	v, _ := strconv.Atoi(s)
	return v
}

func ToStrArr(k string) []string {
	arr := strings.Split(k, ",")
	outArr := []string{}
	for i := range arr {
		s := strings.TrimSpace(arr[i])
		if len(s) > 0 {
			outArr = append(outArr, s)
		}
	}
	return outArr
}

func ToDuration(s string) time.Duration {
	var d time.Duration
	for _, c := range []struct {
		key string
		d   time.Duration
	}{
		{"d", time.Hour * 24},
		{"w", time.Hour * 24 * 7},
	} {
		daysPattern := regexp.MustCompile(`(^|[a-z])[0-9]+` + c.key + `($|[0-9])`)
		idxes := daysPattern.FindAllStringIndex(s, -1)
		if len(idxes) > 1 {
			return 0
		}
		for _, idx := range idxes {
			substr := s[idx[0]:idx[1]]
			for len(substr) > 0 && (substr[0] < '0' || substr[0] > '9') {
				substr = substr[1:]
			}
			for len(substr) > 0 && (substr[len(substr)-1] >= '0' && substr[len(substr)-1] <= '9') {
				substr = substr[:len(substr)-1]
			}
			s = strings.ReplaceAll(s, substr, "")
			substr = strings.TrimSuffix(substr, c.key)
			n, _ := strconv.Atoi(substr)
			d += c.d * time.Duration(n)
		}
	}
	d2, _ := time.ParseDuration(s)
	return d2 + d
}

func ToTime(s string) time.Time {
	v, err := time.Parse("2006-01-02 15:04:05", s)
	if err != nil || v.IsZero() {
		v, err = time.Parse("2006-01-02", s)
	}
	if err != nil || v.IsZero() {
		v, err = time.Parse("1/2/06", s)
	}
	if err != nil || v.IsZero() {
		v, err = time.Parse("02 Jan 2006 3:04 PM", s)
	}
	if err != nil || v.IsZero() {
		v, err = time.Parse("02 Jan 2006 3:04 PM", strings.ReplaceAll(s, "+", " "))
	}
	return v
}