package providers

import (
	"context"
	"fmt"
	"net/url"
	"strconv"
	"strings"
)

// tmdb searches The Movie Database. It accepts either a v3 API key or a v4
// "API Read Access Token".
type tmdb struct {
	r    *Registry
	key  string
	kind string // "movie" or "tv"
}

func (t *tmdb) Name() string  { return "tmdb" }
func (t *tmdb) Label() string { return "TMDB" }

func (t *tmdb) get(ctx context.Context, path string, q url.Values, out any) error {
	if q == nil {
		q = url.Values{}
	}
	header := map[string]string{}
	if strings.HasPrefix(t.key, "eyJ") {
		header["Authorization"] = "Bearer " + t.key
	} else {
		q.Set("api_key", t.key)
	}
	err := t.r.getJSON(ctx, "https://api.themoviedb.org/3"+path+"?"+q.Encode(), header, out)
	if isStatus(err, 401) {
		return fmt.Errorf("TMDB rejected the API key; check it under Settings → Integrations")
	}
	return err
}

func tmdbImage(path string) string {
	if path == "" {
		return ""
	}
	return "https://image.tmdb.org/t/p/w780" + path
}

type tmdbHit struct {
	ID           int64  `json:"id"`
	Title        string `json:"title"`
	Name         string `json:"name"`
	ReleaseDate  string `json:"release_date"`
	FirstAirDate string `json:"first_air_date"`
	PosterPath   string `json:"poster_path"`
	Overview     string `json:"overview"`
}

func (t *tmdb) Search(ctx context.Context, query string) ([]Result, error) {
	var resp struct {
		Results []tmdbHit `json:"results"`
	}
	q := url.Values{"query": {query}, "include_adult": {"false"}}
	if err := t.get(ctx, "/search/"+t.kind, q, &resp); err != nil {
		return nil, err
	}
	out := make([]Result, 0, len(resp.Results))
	for _, h := range resp.Results {
		title, date := h.Title, h.ReleaseDate
		if t.kind == "tv" {
			title, date = h.Name, h.FirstAirDate
		}
		id := strconv.FormatInt(h.ID, 10)
		out = append(out, Result{
			Provider:    "tmdb",
			ProviderID:  t.kind + ":" + id,
			Title:       title,
			Year:        yearOf(date),
			ImageURL:    tmdbImage(h.PosterPath),
			ExternalURL: "https://www.themoviedb.org/" + t.kind + "/" + id,
			Overview:    truncate(h.Overview, maxDescription),
		})
	}
	return out, nil
}

func (t *tmdb) Details(ctx context.Context, res Result) (Result, error) {
	if res.Provider != "tmdb" {
		return res, nil
	}
	_, id, ok := strings.Cut(res.ProviderID, ":")
	if !ok {
		return res, nil
	}
	var d struct {
		Genres []struct {
			Name string `json:"name"`
		} `json:"genres"`
		Runtime  int `json:"runtime"`
		Networks []struct {
			Name string `json:"name"`
		} `json:"networks"`
		CreatedBy []struct {
			Name string `json:"name"`
		} `json:"created_by"`
		Credits struct {
			Crew []struct {
				Name string `json:"name"`
				Job  string `json:"job"`
			} `json:"crew"`
		} `json:"credits"`
	}
	q := url.Values{}
	if t.kind == "movie" {
		q.Set("append_to_response", "credits")
	}
	if err := t.get(ctx, "/"+t.kind+"/"+id, q, &d); err != nil {
		return res, err
	}
	var names []string
	if t.kind == "movie" {
		for _, c := range d.Credits.Crew {
			if c.Job == "Director" {
				names = append(names, c.Name)
			}
		}
	} else {
		for _, n := range d.Networks {
			names = append(names, n.Name)
		}
	}
	if len(names) > 0 {
		res.Subtitle = strings.Join(names, ", ")
	}
	var genres []string
	for _, g := range d.Genres {
		genres = append(genres, g.Name)
	}
	if res.Extra == nil {
		res.Extra = map[string]string{}
	}
	if len(genres) > 0 {
		res.Extra["genres"] = strings.Join(genres, ", ")
	}
	if d.Runtime > 0 {
		res.Extra["runtime"] = fmt.Sprintf("%dh %02dm", d.Runtime/60, d.Runtime%60)
	}
	return res, nil
}

// Lookup refreshes one movie or show ("movie:123" / "tv:456") by its TMDB ID.
func (t *tmdb) Lookup(ctx context.Context, providerID string) (Result, error) {
	kind, id, _ := strings.Cut(providerID, ":")
	if kind != "movie" && kind != "tv" {
		return Result{}, ErrGone
	}
	if _, err := strconv.ParseInt(id, 10, 64); err != nil {
		return Result{}, ErrGone
	}
	var h tmdbHit
	err := t.get(ctx, "/"+kind+"/"+id, nil, &h)
	if isStatus(err, 404) {
		return Result{}, ErrGone
	}
	if err != nil {
		return Result{}, err
	}
	title, date := h.Title, h.ReleaseDate
	if kind == "tv" {
		title, date = h.Name, h.FirstAirDate
	}
	res := Result{
		Provider:    "tmdb",
		ProviderID:  providerID,
		Title:       title,
		Year:        yearOf(date),
		ImageURL:    tmdbImage(h.PosterPath),
		ExternalURL: "https://www.themoviedb.org/" + kind + "/" + id,
		Overview:    truncate(h.Overview, maxDescription),
	}
	d := &tmdb{r: t.r, key: t.key, kind: kind}
	return d.Details(ctx, res)
}