package invidious

import (
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"strconv"
	"time"
)

func (c *Client) fetchVideo(videoId string) (*Video, int) {
	endpoint := fmt.Sprintf(videosEndpoint, c.Instance, url.QueryEscape(videoId))
	resp, err := c.http.Get(endpoint)
	if err != nil {
		logger.Error(err)
		return nil, http.StatusInternalServerError
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		logger.Warn("Invidious gave the following status code: ", resp.StatusCode)
		return nil, http.StatusNotFound
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		logger.Error(err)
		return nil, http.StatusInternalServerError
	}

	res := &Video{}
	err = json.Unmarshal(body, res)
	if err != nil {
		logger.Error(err)
		return nil, http.StatusInternalServerError
	}

	mp4Test := func(f Format) bool { return f.Container == "mp4" }
	res.Formats = filter(res.Formats, mp4Test)

	expireString := expireRegex.FindStringSubmatch(res.Formats[0].Url)
	expireTimestamp, err := strconv.ParseInt(expireString[1], 10, 64)
	if err != nil {
		logger.Error(err)
		return nil, http.StatusInternalServerError
	}
	res.Expire = time.Unix(expireTimestamp, 0)
	return res, http.StatusOK
}

func (c *Client) isNotTimedOut(instance string) bool {
	for i := range c.timeouts {
		cur := c.timeouts[i]
		if instance == cur.Instance {
			return false
		}
	}
	return true
}

func (c *Client) NewInstance() error {
	now := time.Now()

	timeoutsTest := func(t Timeout) bool { return now.Sub(t.Timestamp) < timeoutDuration }
	c.timeouts = filter(c.timeouts, timeoutsTest)
	c.timeouts = append(c.timeouts, Timeout{c.Instance, now})

	resp, err := c.http.Get(instancesEndpoint)
	if err != nil {
		return err
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return err
	}

	if resp.StatusCode != http.StatusOK {
		return HTTPError{resp.StatusCode}
	}

	var jsonArray [][]interface{}
	err = json.Unmarshal(body, &jsonArray)
	if err != nil {
		logger.Error("Could not unmarshal JSON response for instances.")
		return err
	}

	for i := range jsonArray {
		instance := jsonArray[i][0].(string)
		instanceTest := func(t Timeout) bool { return t.Instance == instance }
		result := filter(c.timeouts, instanceTest)
		if len(result) == 0 {
			c.Instance = instance
			logger.Info("Using new instance: ", c.Instance)
			return nil
		}
	}

	return fmt.Errorf("Cannot find a valid instance.")
}