package main

import (
	"encoding/json"
	"errors"
	"fmt"
	"html/template"
	"io"
	"log"
	"net/http"
	"net/url"
	"os"
	"strings"
	"time"
	"crypto/rand"
	"encoding/base64"

	"github.com/tidwall/gjson"

	"context" // <- TODO: what's this??

	"golang.org/x/oauth2"
	//"path/filepath"
	//"regexp"
	//"strings"
	//"maps"
	//"slices"
)


var templates *template.Template = template.New("")
var client = &http.Client{Timeout: 2*time.Second}


type UserInfo struct{
	ProviderCode, // DC--Discord, GG--Google, GH--GitHub, LC--local database
	ExtID,
	Username,
	Fullname,
	Email,
	Locale string

	CreatedTS,
	UpdatedTS int64 // UNIX timestamps
}

var oauth2_dc_config = &oauth2.Config{
	ClientID: os.Getenv("MOIRA_OAUTH2_DC_CLI_ID"),
	ClientSecret: os.Getenv("MOIRA_OAUTH2_DC_CLI_SECRET"),
	Scopes: []string{"identify", "email"},
 	RedirectURL: "https://moira.makemore.cloud/oauth2/ext/dc/clbk/",
	Endpoint: oauth2.Endpoint{
		AuthURL: "https://discord.com/oauth2/authorize",
		TokenURL: "https://discord.com/api/oauth2/token",
	},
}

func oauth2_dc_genRandState() (_ string, err error){
	ret := make([]byte, 24)

	_, err = rand.Read(ret)
	if err != nil{ return }

	return base64.RawURLEncoding.EncodeToString(ret), nil
}

func oauth2_dc_genLoginURL() (_ string, _ *http.Cookie, err error){
	state, err := oauth2_dc_genRandState()
	if err != nil{ return }

	ret_cookie := &http.Cookie{
		Name: "oauth_state",
		Value: state,
		Path: "/",
		HttpOnly: true,
		Secure: true,
		SameSite: http.SameSiteLaxMode, // TODO: what's lax??
		MaxAge: 600,
	}

	return oauth2_dc_config.AuthCodeURL(state), ret_cookie, nil
}

func oauth2_dc_exchangeReceivedCode(req *http.Request) (_ *http.Client, err error){
	cookie, err := req.Cookie("oauth_state")
	if err != nil{ return }
	if cookie.Value != req.URL.Query().Get("state"){
		err = errors.New("oauth2_dc: csrf test failed")
		return
	}

	token, err := oauth2_dc_config.Exchange(context.Background(), req.URL.Query().Get("code"))
	if err != nil{ return }

	return oauth2_dc_config.Client(context.Background(), token), nil
}

func oauth2_fetch_dcUserInfo(in_client *http.Client) (ret []byte, err error){
	req, err := http.NewRequest("GET", "https://discord.com/api/users/@me", nil)
	if err != nil{ return }

	//req.Header.Set("User-Agent", "Mozilla/5.0 (compatible; MoiraBot/1.0)")

	resp,err := in_client.Do(req)
	if err != nil{ return }
	defer resp.Body.Close()

	resp_text, err := io.ReadAll(resp.Body)
	if err != nil{ return }
	//fmt.Printf("%+v\n", string(resp_text))

	return resp_text, nil
}

func oauth2_dcUserInfo_to_UserInfo(resp_text []byte) (ret UserInfo, err error){
	//fmt.Printf("%s\n", string(resp_text))
	// TODO: you might want to check if the data fields are not empty

	ts_now := time.Now().Unix()

	return UserInfo{
		ProviderCode: "DC",
		ExtID: gjson.GetBytes(resp_text, "id").String(),
		Username: gjson.GetBytes(resp_text, "username").String(),
		Fullname: gjson.GetBytes(resp_text, "global_name").String(),
		Email: gjson.GetBytes(resp_text, "email").String(),
		Locale: gjson.GetBytes(resp_text, "locale").String(),

		CreatedTS: ts_now,
		UpdatedTS: ts_now,
	}, nil
}

func oauth2_hdlr_login(resp http.ResponseWriter, req *http.Request){
	url, cookie, err := oauth2_dc_genLoginURL()
	if err != nil {
		http.Error(resp, err.Error(), http.StatusInternalServerError)
	}

	http.SetCookie(resp, cookie)
	http.Redirect(resp, req, url, http.StatusFound)
}

func oauth2_hdlr_clbk(resp http.ResponseWriter, req *http.Request){
	client, err := oauth2_dc_exchangeReceivedCode(req)
	if err != nil { return } // TODO: should the error be reported somehow?

	resp_text, err := oauth2_fetch_dcUserInfo(client)
	if err != nil { return } // TODO: should the error be reported somehow?

	new_userInfo, err := oauth2_dcUserInfo_to_UserInfo(resp_text)
	if err != nil { return } // TODO: should the error be reported somehow?

	t_json, _ := json.MarshalIndent(new_userInfo, "", "	")
	fmt.Printf("%+v\n", string(t_json))
}


type Film struct{
	Title_orig,
	Title_EN,
	Title_PL,
	Desc,
	Img,
	Source string

	Year int
}
var db_film = make(map[string]any)


func findURL_in_msg(in_msg string) (_ string,err error){
	i := strings.Index(in_msg, "http")
	if(i == -1){
		err = errors.New("No URL found in: " + in_msg)
		return
	}

	j := strings.Index(in_msg[i:], " ")
	if(j == -1){
		j = len(in_msg)-i
	}
	
	return in_msg[i:i+j], nil
}

func resolve_redirs(in_url string) (string,error){
	resp, err := client.Get(in_url)
	if(err != nil){
		return "", err
	}
	defer resp.Body.Close()

	return resp.Request.URL.String(), nil
}

func fetch_filmInfo(in_url string) (_ Film, err error){
	parsedUrl, err := url.Parse(in_url)
	if err != nil{ return }
	parsedUrl.RawQuery = ""

	var in_url_api string
	switch(parsedUrl.Hostname()){
		case "www.filmweb.pl":
			in_url_api = fmt.Sprintf(
				"https://www.filmweb.pl/api/v1/film/%s/preview",
				in_url[strings.LastIndex(in_url, "-")+1:],
			)

		case "www.imdb.com":
			t_parsedUrl, _ := url.Parse(in_url)
			t_parsedUrl.RawQuery = ""
			t_parsedUrl.Host = "api.imdbapi.dev"
			in_url_api = strings.Replace(t_parsedUrl.String(), "/title/", "/titles/", 1)

			if in_url_api[len(in_url_api)-1] == '/'{
				in_url_api = in_url_api[:len(in_url_api)-1]
			}

		default:
			err = errors.New("[0] Film database unsupported " + parsedUrl.Hostname())
			return
	}

	fmt.Println("in_url_api:", in_url_api);

	req,err := http.NewRequest("GET", in_url_api, nil)
	if err != nil{ return }

	req.Header.Set("User-Agent", "Mozilla/5.0 (compatible; MoiraBot/1.0)")

	resp,err := client.Do(req)
	if err != nil{ return }
	defer resp.Body.Close()

	resp_text, err := io.ReadAll(resp.Body)
	if err != nil{ return }
	//fmt.Printf("%+v\n", string(resp_text))

	titles := make(map[string]string)
	switch(parsedUrl.Hostname()){
		case "www.filmweb.pl":
			if(len(gjson.GetBytes(resp_text, "internationalTitle").String())>0){
				titles[gjson.GetBytes(resp_text, "internationalTitle.lang").String()] = gjson.GetBytes(resp_text, "internationalTitle.title").String()
				titles["_int"] = gjson.GetBytes(resp_text, "internationalTitle.title").String()
			}
			if(len(gjson.GetBytes(resp_text, "originalTitle").String())>0){
				titles[gjson.GetBytes(resp_text, "originalTitle.lang").String()] = gjson.GetBytes(resp_text, "originalTitle.title").String()
				titles["_orig"] = gjson.GetBytes(resp_text, "originalTitle.title").String()
			}
			if(len(gjson.GetBytes(resp_text, "title").String())>0){
				titles[gjson.GetBytes(resp_text, "title.lang").String()] = gjson.GetBytes(resp_text, "title.title").String()
			}
			return Film{
				Title_orig: (func()string{
					if val,ok:=titles["_orig"]; ok{
						return val
					}else{
						return ""
					}
				})(),
				Title_EN: (func()string{
					if val,ok:=titles["en"]; ok{
						return val
					}else{
						return ""
					}
				})(),
				Title_PL: (func()string{
					if val,ok:=titles["pl"]; ok{
						return val
					}else{
						return ""
					}
				})(),
				Desc: gjson.GetBytes(resp_text, "plotOrDescriptionSynopsis").String(),
				Year: int(gjson.GetBytes(resp_text,"year").Int()),
				Img: "https://fwcdn.pl/fpo"+gjson.GetBytes(resp_text, "poster.path").String(),

				Source: in_url,
			}, err

		case "www.imdb.com":
			if(len(gjson.GetBytes(resp_text, "primaryTitle").String())>0){
				titles["en"] = gjson.GetBytes(resp_text, "primaryTitle").String()
				titles["_int"] = gjson.GetBytes(resp_text, "primaryTitle").String()
			}
			if(len(gjson.GetBytes(resp_text, "originalTitle").String())>0){
				if(len(gjson.GetBytes(resp_text, "originCountries.0.code").String())>0){
					titles[strings.ToLower(gjson.GetBytes(resp_text, "originCountries.0.code").String())] = gjson.GetBytes(resp_text, "originalTitle").String()
				}
				titles["_orig"] = gjson.GetBytes(resp_text, "originalTitle").String()
			}else{
				if val,ok:=titles["_int"]; ok{
					titles["_orig"] = val
				}
			}
			return Film{
				Title_orig: (func()string{
					if val,ok:=titles["_orig"]; ok{
						return val
					}else{
						return ""
					}
				})(),
				Title_EN: (func()string{
					if val,ok:=titles["en"]; ok{
						return val
					}else{
						return ""
					}
				})(),
				Title_PL: (func()string{
					if val,ok:=titles["pl"]; ok{
						return val
					}else{
						return ""
					}
				})(),
				Desc: gjson.GetBytes(resp_text, "plot").String(),
				Year: int(gjson.GetBytes(resp_text,"startYear").Int()),
				Img: gjson.GetBytes(resp_text, "primaryImage.url").String(),

				Source: in_url,
			}, err

		default:
			err = errors.New("[1] Film database unsupported " + parsedUrl.Hostname())
			return
	}
}

func hdlr_root(template_renders map[string]struct{Template string;Context *map[string]any}) http.HandlerFunc{
	fSrv := http.FileServer(http.Dir("./website/static"))

	return func (resp http.ResponseWriter, req *http.Request){
		if fileName, ok := template_renders[req.URL.Path]; ok{
			fmt.Println("[srv] template", req.URL.Path, fileName.Template)

			url_query := req.URL.Query()
			url_query_id := url_query.Get("id")
			var context any
			if(url_query_id != ""){
				context = (*fileName.Context)[url_query_id]
			}else{
				context = nil
			}
			err := templates.ExecuteTemplate(resp, fileName.Template, context)

			if(err != nil){
				http.Error(resp, err.Error(), http.StatusInternalServerError)
			}
		}else{
			fmt.Println("[srv] static", req.URL.Path)

			fSrv.ServeHTTP(resp, req)
		}
	}
}

func templates_register(template_renders map[string]struct{Template string;Context *map[string]any}){
	for _,i_file := range template_renders{
		text, err := os.ReadFile("./website/templates/" + i_file.Template)
		if(err != nil){
			panic(err)
		}

		templates.New(i_file.Template).Parse(string(text))
	}
}

func hdlr_film_parseMsg(resp http.ResponseWriter, req *http.Request){
	fmt.Println("[srv] util", req.URL)

	url_query := req.URL.Query()

	t_url, _ := findURL_in_msg(url_query.Get("text"))
	fmt.Println(t_url)
	t_url_noRed, _ := resolve_redirs(t_url)
	fmt.Println(t_url_noRed)
	t_film, _ := fetch_filmInfo(t_url_noRed)

	db_film[fmt.Sprintf("%d",len(db_film))] = t_film

	t_json, _ := json.MarshalIndent(db_film, "", "	")
	fmt.Printf("%+v\n", string(t_json))
	fmt.Println("/film/view/?id="+fmt.Sprintf("%d",len(db_film)-1))

	http.Redirect(resp, req, "/film/view/?id="+fmt.Sprintf("%d",len(db_film)-1), http.StatusFound)
}

func main(){
	fmt.Println("CLIENT_ID:", oauth2_dc_config.ClientID);
	fmt.Println("CLIENT_SECRET:", oauth2_dc_config.ClientSecret);

	//t_film, _ := fetch_filmInfo("https://www.filmweb.pl/film/Spirited+Away%3A+W+krainie+Bog%C3%B3w-2001-33288")
	//t_film, _ := fetch_filmInfo("https://www.filmweb.pl/film/Pulp+Fiction-1994-1039")
	//t_film, _ := fetch_filmInfo("https://www.filmweb.pl/film/Kl%C4%85twa+Doliny+W%C4%99%C5%BCy-1987-6785")
	//t_film, _ := fetch_filmInfo("https://www.imdb.com/title/tt0245429/?ref_=nv_sr_srsg_0_tt_8_nm_0_in_0_q_spirited")
	//t_film, _ := fetch_filmInfo("https://www.imdb.com/title/tt0110912/")
	//t_film, _ := fetch_filmInfo("https://www.imdb.com/title/tt8814476/")

	//t_url_noRed, _ := resolve_redirs("https://www.imdb.com/title/tt0095456/?ref_=nv_sr_srsg_0_tt_1_nm_0_in_0_q_kl%C4%85twa%20doliny%20w%C4%99%C5%BC")
	//t_url_noRed, _ := resolve_redirs("https://share.google/EsMXhLYol3eQTKcQH")

	//t_url, _ := findURL_in_msg("https://share.google/EsMXhLYol3eQTKcQH")
	//t_url, _ := findURL_in_msg("abcabc https://share.google/EsMXhLYol3eQTKcQH abcabc")
	//t_url, _ := findURL_in_msg("abcabchttps://share.google/EsMXhLYol3eQTKcQH abcabc")
	//t_url, _ := findURL_in_msg("abcabchttps://share.google/EsMXhLYol3eQTKcQH")
	//t_url, _ := findURL_in_msg("Fantastyczny Pan Lis (2009) - Filmweb https://share.google/EsMXhLYol3eQTKcQH")
	//fmt.Println(t_url)

	//t_url_noRed, _ := resolve_redirs(t_url)
	//fmt.Println(t_url_noRed)
	//t_film, _ := fetch_filmInfo(t_url_noRed)
	//t_json, _ := json.MarshalIndent(t_film, "", "	")
	//fmt.Printf("%+v\n", string(t_json))

	template_renders := map[string]struct{Template string;Context *map[string]any} {
		"/": {"index.html", nil},
		"/film/view/": {"film/view/index.html", &db_film},
		"/film/edit/": {"index.html", nil},
		//"/list/view/": {"index.html", nil},
		//"/list/edit/": {"index.html", nil},
		//"/group/view/": {"index.html", nil},
		//"/group/edit/": {"index.html", nil},
	}

	templates_register(template_renders)
	http.HandleFunc("/", hdlr_root(template_renders))


	http.HandleFunc("/film/parse_msg/", hdlr_film_parseMsg)
	http.HandleFunc("/oauth2/ext/dc/login/", oauth2_hdlr_login)
	http.HandleFunc("/oauth2/ext/dc/clbk/", oauth2_hdlr_clbk)


	//fmt.Println("Welcome to moira_db!");
	log.Fatal(http.ListenAndServe(":8099", nil))
}