package main

import (
	"database/sql"
	"fmt"
	"log"
	"net/http"
	"slices"
	"strings"
	"time"

	"humungus.tedunangst.com/r/webs/junk"
	"humungus.tedunangst.com/r/webs/login"
)

type MastoApp struct {
	Name         string `db:"clientname"`
	RedirectURI  string `db:"redirecturis"`
	ClientID     string `db:"clientid"`
	ClientSecret string `db:"clientsecret"`
	VapidKey     string `db:"vapidkey"`
	AuthToken    string `db:"authtoken"`
	Scopes       string `db:"scopes"`
}

func showoauthlogin(rw http.ResponseWriter, r *http.Request) {
	templinfo := make(map[string]interface{})
	templinfo = getInfo(r)
	templinfo["ClientID"] = r.URL.Query().Get("client_id")
	templinfo["RedirectURI"] = r.URL.Query().Get("redirect_uri")

	if err := readviews.Execute(rw, "oauthlogin.html", templinfo); err != nil {
		elog.Println(err)
	}
}

// https://docs.joinmastodon.org/methods/apps/#create
func apiapps(rw http.ResponseWriter, r *http.Request) {
	if err := r.ParseForm(); err != nil {
		http.Error(rw, "invalid input", http.StatusUnprocessableEntity)
		elog.Println(err)
		return
	}
	clientName := r.Form.Get("client_name")
	redirectURI := r.Form.Get("redirect_uris")
	scopes := r.Form.Get("scopes")
	website := r.Form.Get("website")
	clientID := tokengen()
	clientSecret := tokengen()
	vapidKey := tokengen()

	_, err := stmtSaveMastoApp.Exec(clientName, redirectURI, scopes, clientID, clientSecret, vapidKey, "")
	if err != nil {
		elog.Printf("error saving masto app: %v", err)
		http.Error(rw, "error saving masto app", http.StatusUnprocessableEntity)
		return
	}

	j := junk.New()
	j["id"] = "19"
	j["website"] = website
	j["name"] = clientName
	j["redirect_uri"] = redirectURI
	j["client_id"] = clientID
	j["client_secret"] = clientSecret
	j["vapid_key"] = vapidKey

	fmt.Println(j.ToString())
	goodjunk(rw, j)
}

// https://docs.joinmastodon.org/methods/oauth/#authorize
func oauthorize(rw http.ResponseWriter, r *http.Request) {
	clientID := r.FormValue("client_id")
	redirectURI := r.FormValue("redirect_uri")

	if !checkClientID(clientID) {
		elog.Println("oauth: no such client:", clientID)
		rw.WriteHeader(http.StatusUnauthorized)
		return
	}

	var nrw NotResponseWriter
	login.LoginFunc(&nrw, r)

	_, err := stmtSaveMastoAppToken.Exec(nrw.auth)
	if err != nil {
		elog.Println("oauth: failed to save masto app token", err)
		rw.WriteHeader(http.StatusInternalServerError)
		return
	}

	uri := fmt.Sprintf("%s?code=%s", redirectURI, nrw.auth)

	log.Println("redirecting to", uri)
	rw.Header().Set("Content-Type", "")
	rw.Header().Set("Location", uri)
	rw.WriteHeader(302)
}

// https://docs.joinmastodon.org/methods/oauth/#token
func oauthtoken(rw http.ResponseWriter, r *http.Request) {
	grantType := r.FormValue("grant_type")
	code := r.FormValue("code")
	clientID := r.FormValue("client_id")
	clientSecret := r.FormValue("client_secret")
	redirectURI := r.FormValue("redirect_uri")
	gotScope := r.FormValue("scope")

	if !checkClient(clientID, clientSecret) {
		elog.Println("oauth: no such client:", clientID)
		rw.WriteHeader(http.StatusBadRequest)
		return
	}

	app := MastoApp{}
	row := stmtGetMastoApp.QueryRowx(clientID)
	err := row.StructScan(&app)
	if err == sql.ErrNoRows {
		elog.Printf("oauth: invalid client: %s\n", clientID)
		rw.WriteHeader(http.StatusBadRequest)
		return
	}
	log.Printf("%#v", app)

	possibleScopes := strings.Split(app.Scopes, " ")
	requestedScopes := strings.Split(gotScope, " ")
	for _, scope := range requestedScopes {
		if !slices.Contains(possibleScopes, scope) {
			elog.Printf("oauth: invalid scope: %s", scope)
			rw.WriteHeader(http.StatusBadRequest)
			return
		}
	}

	if app.Scopes != gotScope {
		elog.Printf("oauth: bad scopes: got %s; want %s", gotScope, app.Scopes)
		rw.WriteHeader(http.StatusBadRequest)
		return
	}

	if app.RedirectURI != redirectURI {
		elog.Println("oauth: incorrect redirect URI")
		rw.WriteHeader(http.StatusBadRequest)
		return
	}

	if grantType == "authorization_code" {
		// idk if this is ok? should code be reset?
		if app.AuthToken == code {
			accessToken := tokengen()
			_, err := stmtSaveMastoAccessToken.Exec(app.ClientID, accessToken)
			if err != nil {
				elog.Println("oauth: failed to save masto access token", err)
				rw.WriteHeader(http.StatusInternalServerError)
				return
			}
			j := junk.New()
			j["access_token"] = accessToken
			j["token_type"] = "Bearer"
			j["scope"] = app.Scopes
			j["created_at"] = time.Now().UTC().Unix()
			goodjunk(rw, j)
		}
	} else {
		// gaslight the client
		elog.Println("oauth: bad grant_type: must be authorization_code")
		rw.WriteHeader(http.StatusBadRequest)
		return
	}
}

// https://docs.joinmastodon.org/methods/instance/#v2
func instance(rw http.ResponseWriter, r *http.Request) {
	j := junk.New()

	var servername string
	if err := getconfig("servername", &servername); err != nil {
		http.Error(rw, "getting servername", http.StatusInternalServerError)
		return
	}

	j["uri"] = servername
	j["title"] = "honk"
	j["description"] = "federated honk conveyance"
	j["version"] = "develop"

	thumbnail := junk.New()
	thumbnail["url"] = fmt.Sprintf("https://%s/icon.png", servername)
	j["thumbnail"] = thumbnail
	j["languages"] = []string{"en"}

	config := junk.New()

	a := junk.New()
	a["max_featured_tags"] = 10
	config["accounts"] = a

	s := junk.New()
	s["max_characters"] = 5000
	s["max_media_attachments"] = 1
	s["characters_reserved_per_url"] = 23
	config["statuses"] = s

	m := junk.New()
	m["supported_mime_types"] = []string{
		"image/jpeg",
		"image/png",
		"image/gif",
		"image/heic",
		"image/heif",
		"image/webp",
		"image/avif",
		"video/webm",
		"video/mp4",
		"video/quicktime",
		"video/ogg",
		"audio/wave",
		"audio/wav",
		"audio/x-wav",
		"audio/x-pn-wave",
		"audio/vnd.wave",
		"audio/ogg",
		"audio/vorbis",
		"audio/mpeg",
		"audio/mp3",
		"audio/webm",
		"audio/flac",
		"audio/aac",
		"audio/m4a",
		"audio/x-m4a",
		"audio/mp4",
		"audio/3gpp",
		"video/x-ms-asf",
	}

	m["image_size_limit"] = 10485760
	m["image_matrix_limit"] = 16777216
	m["video_size_limit"] = 41943040
	m["video_frame_rate_limit"] = 60
	m["video_matrix_limit"] = 2304000
	j["media_attachments"] = m

	goodjunk(rw, j)

	return
}

// https://docs.joinmastodon.org/methods/accounts/#verify_credentials
func verifycreds(rw http.ResponseWriter, r *http.Request) {
	user, ok := somenumberedusers.Get(UserID(1))
	if !ok {
		elog.Fatalf("masto: no user number 1???")
	}
	j := junk.New()
	j["id"] = user.ID
	j["username"] = user.Name
	j["acct"] = user.Name
	j["display_name"] = user.Options.CustomDisplay
	j["url"] = user.URL
	j["note"] = user.HTAbout
	j["avatar"] = user.Options.Avatar
	j["header"] = user.Options.Banner
	j["followers_count"] = 0
	j["following_count"] = 0
	j["statuses_count"] = getlocalhonkcount()

	s := junk.New()
	s["note"] = user.About
	s["privacy"] = "public"
	j["source"] = s

	goodjunk(rw, j)
}