package controller

import (
	"fmt"
	"net/http"
	"strconv"

	"github.com/fjurmanovic/sugarr/internal/model"
	"github.com/fjurmanovic/sugarr/internal/service"
	"github.com/fjurmanovic/sugarr/internal/utl/configs"
	"github.com/fjurmanovic/sugarr/internal/utl/httputil"
	"github.com/rs/zerolog/log"
)

type RecommendationsController struct {
	cfg *configs.Config
	rec *service.Recommender
}

func NewRecommendationsController(mux *http.ServeMux, cfg *configs.Config, rec *service.Recommender) *RecommendationsController {
	c := &RecommendationsController{cfg: cfg, rec: rec}
	mux.HandleFunc("GET /recommendations", c.handleList)
	mux.HandleFunc("POST /recommendations/search", c.handleSearch)
	return c
}

// handleList runs the recommendation pipeline and returns results as JSON.
// Query params: ?count=10&force_llm=true&force_tmdb=true
func (c *RecommendationsController) handleList(w http.ResponseWriter, r *http.Request) {
	count := c.cfg.RecommendCount
	if v := r.URL.Query().Get("count"); v != "" {
		if n, err := strconv.Atoi(v); err == nil && n > 0 {
			count = n
		}
	}

	// Temporarily override LLM flag for force_llm / force_tmdb params
	origLLM := c.cfg.LLMEnabled
	if r.URL.Query().Get("force_llm") == "true" {
		c.cfg.LLMEnabled = true
	} else if r.URL.Query().Get("force_tmdb") == "true" {
		c.cfg.LLMEnabled = false
	}

	recs, err := c.rec.RunWithCount(count)
	c.cfg.LLMEnabled = origLLM

	if err != nil {
		log.Error().Err(err).Msg("Recommendation pipeline failed")
		httputil.WriteError(w, http.StatusInternalServerError, err.Error())
		return
	}
	httputil.WriteJSON(w, http.StatusOK, recs)
}

// handleSearch performs a natural-language LLM search and resolves results via TMDb.
// Body: {"query": "sci-fi movies like Blade Runner but more recent"}
func (c *RecommendationsController) handleSearch(w http.ResponseWriter, r *http.Request) {
	if !c.cfg.LLMEnabled || c.rec.LLM() == nil {
		httputil.WriteError(w, http.StatusBadRequest, "LLM is not enabled")
		return
	}

	var body struct {
		Query string `json:"query"`
	}
	if err := decodeJSON(r, &body); err != nil || body.Query == "" {
		httputil.WriteError(w, http.StatusBadRequest, "body must be {\"query\": \"...\"}")
		return
	}

	prompt := fmt.Sprintf(
		"You are a movie recommendation engine. The user is looking for: %s\n\n"+
			"Return ONLY a JSON array of %d movies matching this request. No other text.\n"+
			"Each entry: {\"title\": \"Movie Title\", \"year\": 2024, \"reason\": \"brief reason\"}",
		body.Query, c.cfg.RecommendCount)

	suggestions, err := c.rec.LLM().Recommend(prompt)
	if err != nil {
		log.Error().Err(err).Msg("LLM search failed")
		httputil.WriteError(w, http.StatusInternalServerError, err.Error())
		return
	}

	library, _ := c.rec.Jellyfin().GetAllMovies()
	exclude := map[int]bool{}
	for _, m := range library {
		if id, err := strconv.Atoi(m.TMDbID); err == nil && id != 0 {
			exclude[id] = true
		}
	}

	var recs []model.Recommendation
	for _, sug := range suggestions {
		if len(recs) >= c.cfg.RecommendCount {
			break
		}
		tm, err := c.rec.TMDb().SearchMovie(sug.Title, sug.Year)
		if err != nil || tm == nil || exclude[tm.ID] {
			continue
		}
		exclude[tm.ID] = true
		recs = append(recs, model.Recommendation{
			Title:  tm.Title,
			Year:   tm.Year,
			TMDbID: tm.ID,
			Reason: sug.Reason,
		})
	}
	httputil.WriteJSON(w, http.StatusOK, recs)
}