package main

import (
	"fmt"
	"net/http"
	"strconv"
	"strings"
	"time"
)

func isMethodAllowed(response *http.ResponseWriter, request *http.Request) bool {
	if request.Method != http.MethodPost {
		http.Error(*response, "POST only", http.StatusMethodNotAllowed)
		return false
	}
	return true
}

func parseRgb(str string) ([3]uint8, error) {
	parts := strings.SplitN(str, ",", 4)
	if len(parts) != 3 {
		return [3]uint8{}, fmt.Errorf("invalid rgb")
	}
	var rgb [3]uint8
	for i, p := range parts {
		n, err := strconv.ParseUint(strings.TrimSpace(p), 10, 8)
		if err != nil {
			return [3]uint8{}, fmt.Errorf("invalid component %d: %w", i, err)
		}
		rgb[i] = uint8(n)
	}
	return rgb, nil
}

func HttpHandleNewUser(response http.ResponseWriter, request *http.Request) {
	if !isMethodAllowed(&response, request) {
		return
	}

	username := request.FormValue("username")
	if len(username) < 4 {
		http.Error(response, "no or short username", http.StatusBadRequest)
		return
	}

	password := request.FormValue("password")
	if len(password) < 8 {
		http.Error(response, "no or short password", http.StatusBadRequest)
		return
	}

	color, err := parseRgb(request.FormValue("color"))
	if err != nil {
		http.Error(response, "bad color", http.StatusBadRequest)
	}

	hashedPassword, err := PasswordHash(password)
	if err != nil {
		http.Error(response, "internal server error", http.StatusInternalServerError)
		return
	}

	newClient := &Client{
		Name:         username,
		PasswordHash: hashedPassword,
		Color:        color,
		CreatedAt:    time.Now(),
	}

	ctx := request.Context()

	err = DbSaveClientWithoutGroups(ctx, newClient)
	if err != nil {
		http.Error(response, "name taken", http.StatusInternalServerError)
		return
	}
}

func HttpHandleLogin(response http.ResponseWriter, request *http.Request) {
	if !isMethodAllowed(&response, request) {
		return
	}

	username := request.FormValue("username")
	if len(username) < 4 {
		http.Error(response, "no or short username", http.StatusBadRequest)
		return
	}

	var client = Client{Name: username}
	if len(client.Name) < 8 {
		http.Error(response, "no or short password", http.StatusBadRequest)
		return
	}

	ctx := request.Context()

	err := DbSetClientByName(ctx, &client)
	if err != nil {
		return
	}

	_, err = CacheGetClientById(client.Id)
	if err == nil {
		otherLoggedIn, err := CacheGetClientById(client.Id)
		if err == nil {
			otherLoggedIn.WsConn.CloseNow()
		}
	}

	token, err := TokenCreate(client.Id)
	if err != nil {
		http.Error(response, "internal server error", http.StatusInternalServerError)
	}
	response.Write([]byte(token))
}

func HttpHandleGroupCreate(response http.ResponseWriter, request *http.Request) {
	if !isMethodAllowed(&response, request) {
		return
	}
}