package httpapi

import (
	"log/slog"
	"net/http"
	"strings"

	"github.com/mitbringsl/backend/internal/store"
)

// SuggestHandler handles the /api/suggestions endpoint.
type SuggestHandler struct {
	suggest *store.SuggestStore
}

// NewSuggestHandler creates a SuggestHandler backed by the given store.
func NewSuggestHandler(suggest *store.SuggestStore) *SuggestHandler {
	return &SuggestHandler{suggest: suggest}
}

type suggestResponse struct {
	Suggestions []string `json:"suggestions"`
}

// Search returns autocomplete suggestions for item names matching the query.
//
// GET /api/suggestions?q=<query>
func (h *SuggestHandler) Search(w http.ResponseWriter, r *http.Request) {
	q := strings.TrimSpace(r.URL.Query().Get("q"))
	if q == "" {
		renderError(w, http.StatusBadRequest, "Bad request", "Query parameter 'q' is required.")
		return
	}
	// Lowercase so the trgm index can match correctly.
	q = strings.ToLower(q)

	names, err := h.suggest.Search(r.Context(), q)
	if err != nil {
		slog.Error("suggest search failed", "error", err, "q", q)
		renderError(w, http.StatusInternalServerError, "Internal error", "Could not load suggestions.")
		return
	}
	if names == nil {
		names = []string{}
	}
	renderJSON(w, http.StatusOK, suggestResponse{Suggestions: names})
}