package main

import (
	"bytes"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"os/signal"
	"syscall"
	"time"
)

func main() {
	ctx, can := signal.NotifyContext(context.Background(), syscall.SIGINT)
	defer can()

	jellyFrom, err := NewJelly(ctx, "squeaky2x3", "aFJKcZ4fUuN9FZ", "5c1de748f61145a085f272aea527c759", "213abf9acbe84d9fb9c3b06bbe1eec3b")
	if err != nil {
		panic(err)
	}
	log.Printf("from %+v", jellyFrom)

	jellyTo, err := NewJelly(ctx, "belly", "qBentOcpHMUjhD", "497b212a22e34b54be091055edbe264d", "b71b931108ba4323b75b675871a7738f")
	if err != nil {
		panic(err)
	}
	log.Printf("to   %+v", jellyTo)

	log.Fatalf("not impl: %+v => %+v", jellyFrom, jellyTo)
}

type Jelly struct {
	u           string
	apitoken    string
	accesstoken string
}

func NewJelly(ctx context.Context, u, p, apitoken, optAccessToken string) (Jelly, error) {
	jelly := Jelly{u: u, apitoken: apitoken, accesstoken: optAccessToken}

	if optAccessToken == "" {
		resp, err := jelly.post(ctx, "https://jellyfin.home.blapointe.com/Users/AuthenticateByName", map[string]string{
			"Username": u,
			"Pw":       p,
		}, "Authorization", jelly._authHeader(jelly.apitoken))
		if err != nil {
			return Jelly{}, err
		}

		var AccessToken struct {
			AccessToken string
		}
		if err := json.NewDecoder(resp.Body).Decode(&AccessToken); err != nil {
			return Jelly{}, err
		}
		jelly.accesstoken = AccessToken.AccessToken
	}

	return jelly, nil
}

func (jelly Jelly) authHeader() string {
	return jelly._authHeader(jelly.accesstoken)
}

func (jelly Jelly) _authHeader(token string) string {
	return fmt.Sprintf("MediaBrowser Token=%q, Client=%q, Version=%q, DeviceId=%q, Device=%q", token, "client", "version", "deviceId"+jelly.u, "device")
}

func (jelly Jelly) post(ctx context.Context, url string, body any, headers ...string) (*http.Response, error) {
	t := http.Transport{
		DisableKeepAlives: true,
	}
	c := http.Client{
		Timeout:   time.Minute,
		Transport: &t,
	}

	b, _ := json.Marshal(body)
	req, err := http.NewRequest(http.MethodPost, url, bytes.NewReader(b))
	if err != nil {
		return nil, err
	}

	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("Authorization", jelly.authHeader())
	req = req.WithContext(ctx)
	for i := 0; i+1 < len(headers); i += 2 {
		req.Header.Set(headers[i], headers[i+1])
	}

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

	b, _ = io.ReadAll(resp.Body)
	resp.Body = io.NopCloser(bytes.NewReader(b))

	if resp.StatusCode >= 400 {
		return nil, fmt.Errorf("(%d) %s", resp.StatusCode, b)
	}

	return resp, nil
}