package torrent

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

	"github.com/rs/zerolog/log"
)

type QbittorrentClient struct {
	baseURL string
	client  *http.Client
	sid     string
}

func NewQbittorrentClient(baseURL string) *QbittorrentClient {
	return &QbittorrentClient{
		baseURL: strings.TrimRight(baseURL, "/"),
		client: &http.Client{
			Timeout: 10 * time.Second,
		},
	}
}

func (c *QbittorrentClient) Login(username string, password string) (string, error) {
	log.Trace().Str("url", c.baseURL).Str("username", username).Msg("qbittorrent login attempt")

	data := url.Values{
		"username": {username},
		"password": {password},
	}

	start := time.Now()
	resp, err := c.client.PostForm(c.baseURL+"/api/v2/auth/login", data)
	if err != nil {
		log.Error().Err(err).Str("url", c.baseURL).Msg("qbittorrent login request failed")
		return "", fmt.Errorf("login request failed: %w", err)
	}
	defer resp.Body.Close()

	log.Trace().Int("status", resp.StatusCode).Dur("duration", time.Since(start)).Msg("qbittorrent login response")

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		log.Error().Err(err).Msg("qbittorrent reading login response failed")
		return "", fmt.Errorf("reading login response: %w", err)
	}

	if resp.StatusCode == http.StatusForbidden {
		log.Warn().Msg("qbittorrent login forbidden: too many failed attempts")
		return "", fmt.Errorf("login forbidden: too many failed attempts")
	}

	if string(body) != "Ok." {
		log.Warn().Str("response", string(body)).Msg("qbittorrent login rejected")
		return "", fmt.Errorf("login failed: %s", string(body))
	}

	for _, cookie := range resp.Cookies() {
		if cookie.Name == "SID" {
			c.sid = cookie.Value
			log.Info().Str("url", c.baseURL).Msg("qbittorrent login successful")
			log.Trace().Str("sid", c.sid).Msg("qbittorrent session ID acquired")
			return c.sid, nil
		}
	}

	log.Error().Msg("qbittorrent login succeeded but no SID cookie returned")
	return "", fmt.Errorf("login succeeded but no SID cookie returned")
}

func (c *QbittorrentClient) List() ([]TorrentInfo, error) {
	log.Trace().Msg("qbittorrent listing torrents")

	req, err := http.NewRequest("GET", c.baseURL+"/api/v2/torrents/info", nil)
	if err != nil {
		log.Error().Err(err).Msg("qbittorrent creating list request failed")
		return nil, fmt.Errorf("creating list request: %w", err)
	}
	req.AddCookie(&http.Cookie{Name: "SID", Value: c.sid})

	start := time.Now()
	resp, err := c.client.Do(req)
	if err != nil {
		log.Error().Err(err).Msg("qbittorrent list request failed")
		return nil, fmt.Errorf("list request failed: %w", err)
	}
	defer resp.Body.Close()

	log.Trace().Int("status", resp.StatusCode).Dur("duration", time.Since(start)).Msg("qbittorrent list response")

	if resp.StatusCode != http.StatusOK {
		log.Error().Int("status", resp.StatusCode).Msg("qbittorrent list returned non-OK status")
		return nil, fmt.Errorf("list request returned status %d", resp.StatusCode)
	}

	var items []QbittorrentListItem
	if err := json.NewDecoder(resp.Body).Decode(&items); err != nil {
		log.Error().Err(err).Msg("qbittorrent decoding list response failed")
		return nil, fmt.Errorf("decoding list response: %w", err)
	}

	torrents := make([]TorrentInfo, len(items))
	for i, item := range items {
		torrents[i] = item.toTorrentInfo()
	}

	log.Debug().Int("count", len(torrents)).Msg("qbittorrent torrents listed")

	return torrents, nil
}

type QbittorrentListItem struct {
	Hash         string  `json:"hash"`
	Name         string  `json:"name"`
	Size         int64   `json:"size"`
	Progress     float64 `json:"progress"`
	DlSpeed      int64   `json:"dlspeed"`
	UpSpeed      int64   `json:"upspeed"`
	NumSeeds     int32   `json:"num_seeds"`
	NumLeechs    int32   `json:"num_leechs"`
	State        string  `json:"state"`
	ETA          int64   `json:"eta"`
	Ratio        float64 `json:"ratio"`
	Category     string  `json:"category"`
	Tags         string  `json:"tags"`
	AddedOn      int64   `json:"added_on"`
	CompletionOn int64   `json:"completion_on"`
	SavePath     string  `json:"save_path"`
	ContentPath  string  `json:"content_path"`
	Downloaded   int64   `json:"downloaded"`
	Uploaded     int64   `json:"uploaded"`
	Tracker      string  `json:"tracker"`
	SeedingTime  int64   `json:"seeding_time"`
	AmountLeft   int64   `json:"amount_left"`
	Availability float64 `json:"availability"`
}

func (t *QbittorrentListItem) toTorrentInfo() TorrentInfo {
	return TorrentInfo{
		Hash:         t.Hash,
		Name:         t.Name,
		Size:         t.Size,
		Progress:     t.Progress,
		DlSpeed:      t.DlSpeed,
		UpSpeed:      t.UpSpeed,
		NumSeeds:     t.NumSeeds,
		NumLeechs:    t.NumLeechs,
		State:        t.State,
		ETA:          t.ETA,
		Ratio:        t.Ratio,
		Category:     t.Category,
		Tags:         t.Tags,
		AddedOn:      t.AddedOn,
		CompletionOn: t.CompletionOn,
		SavePath:     t.SavePath,
		ContentPath:  t.ContentPath,
		Downloaded:   t.Downloaded,
		Uploaded:     t.Uploaded,
		Tracker:      t.Tracker,
		SeedingTime:  t.SeedingTime,
		AmountLeft:   t.AmountLeft,
		Availability: t.Availability,
	}
}