package main

import (
	"encoding/json"
	"net/http"
	"unicode"

	"github.com/go-playground/validator/v10"
)

var Validate *validator.Validate

func init() {
	Validate = validator.New(validator.WithRequiredStructEnabled())
	Validate.RegisterValidation("password", validatePassword)
}

func writeJSON(w http.ResponseWriter, status int, data any) error {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	return json.NewEncoder(w).Encode(data)
}

func readJSON(w http.ResponseWriter, r *http.Request, data any) error {
	maxBytes := 1_048_578 // 1MB
	r.Body = http.MaxBytesReader(w, r.Body, int64(maxBytes))

	decoder := json.NewDecoder(r.Body)
	decoder.DisallowUnknownFields()

	return decoder.Decode(data)
}

func errorJSON(w http.ResponseWriter, status int, err string) error {
	type envelope struct {
		Error string `json:"error"`
	}

	return writeJSON(w, status, &envelope{Error: err})
}

func (api *api) jsonResponse(w http.ResponseWriter, status int, data any) error {
	type envelope struct {
		Data any `json:"data"`
	}
	return writeJSON(w, status, &envelope{Data: data})
}

func validatePassword(fl validator.FieldLevel) bool {
	password := fl.Field().String()

	var (
		hasMinLen = len(password) >= 8
		hasMaxLen = len(password) <= 72
		hasUpper  = false
		hasLower  = false
		hasNumber = false
		hasSymbol = false
	)

	for _, char := range password {
		switch {
		case unicode.IsUpper(char):
			hasUpper = true
		case unicode.IsLower(char):
			hasLower = true
		case unicode.IsNumber(char):
			hasNumber = true
		case unicode.IsPunct(char) || unicode.IsSymbol(char):
			hasSymbol = true
		}
	}

	return hasMinLen && hasMaxLen && hasUpper && hasLower && hasNumber && hasSymbol
}