package store

import (
	"context"
	"fmt"
	"strings"
	"time"
)

// MediaRequest is one viewer's ask, as recorded. It carries no status: see the schema
// comment on media_requests for why the state is derived per read rather than stored.
type MediaRequest struct {
	MediaType   string    `json:"mediaType"`
	ForeignID   int       `json:"foreignId"`
	Title       string    `json:"title"`
	Year        int       `json:"year,omitempty"`
	PosterURL   string    `json:"posterUrl,omitempty"`
	RequestedAt time.Time `json:"requestedAt"`
}

// MediaRequestLimit caps what one viewer's page will read back. A household that has been
// asking for things for two years should not turn the page into an unbounded query, and
// nobody scrolls past the most recent hundred by remote.
const MediaRequestLimit = 100

// SaveMediaRequest records an ask, or refreshes one already held.
//
// The repeat is deliberately an update rather than a no-op: asking again is how somebody
// says they still want it, and the page is ordered by when they asked.
func (s *Store) SaveMediaRequest(ctx context.Context, userID string, req MediaRequest) error {
	userID = strings.TrimSpace(userID)
	if userID == "" || req.ForeignID <= 0 {
		return fmt.Errorf("store: media request needs a user and a foreign id")
	}
	_, err := s.pool.Exec(ctx, `
		INSERT INTO media_requests
			(emby_user_id, media_type, foreign_id, title, year, poster_url, requested_at)
		VALUES ($1, $2, $3, $4, $5, $6, now())
		ON CONFLICT (emby_user_id, media_type, foreign_id) DO UPDATE
		SET title        = EXCLUDED.title,
		    year         = EXCLUDED.year,
		    poster_url   = EXCLUDED.poster_url,
		    requested_at = now()`,
		userID, req.MediaType, req.ForeignID, req.Title, req.Year, req.PosterURL)
	if err != nil {
		return fmt.Errorf("store: save media request: %w", err)
	}
	return nil
}

// MediaRequests returns one viewer's asks, most recent first.
func (s *Store) MediaRequests(ctx context.Context, userID string) ([]MediaRequest, error) {
	rows, err := s.pool.Query(ctx, `
		SELECT media_type, foreign_id, title, year, poster_url, requested_at
		FROM media_requests
		WHERE emby_user_id = $1
		ORDER BY requested_at DESC
		LIMIT $2`, strings.TrimSpace(userID), MediaRequestLimit)
	if err != nil {
		return nil, fmt.Errorf("store: read media requests: %w", err)
	}
	defer rows.Close()

	requests := []MediaRequest{}
	for rows.Next() {
		var req MediaRequest
		if err := rows.Scan(
			&req.MediaType, &req.ForeignID, &req.Title, &req.Year, &req.PosterURL, &req.RequestedAt,
		); err != nil {
			return nil, fmt.Errorf("store: scan media request: %w", err)
		}
		requests = append(requests, req)
	}
	return requests, rows.Err()
}

// DeleteMediaRequest removes a viewer's ask from their own page.
//
// It deliberately does not touch Radarr or Sonarr. The title may well have been downloaded
// by now, and other people may have asked for it too — this only says the viewer no longer
// wants it listed among theirs.
func (s *Store) DeleteMediaRequest(
	ctx context.Context, userID, mediaType string, foreignID int,
) error {
	_, err := s.pool.Exec(ctx, `
		DELETE FROM media_requests
		WHERE emby_user_id = $1 AND media_type = $2 AND foreign_id = $3`,
		strings.TrimSpace(userID), mediaType, foreignID)
	if err != nil {
		return fmt.Errorf("store: delete media request: %w", err)
	}
	return nil
}