package repository

import (
	"context"
	"errors"
	"fmt"
	"strings"

	"github.com/jackc/pgx/v5"
	"github.com/prabhupadasays/spsays-bff/internal/model"
)

var ErrBookmarkNotFound = errors.New("bookmark not found")
var ErrBookmarkExists = errors.New("bookmark already exists for this URL")

type BookmarkRepo struct{ pg *Postgres }

func NewBookmarkRepo(pg *Postgres) *BookmarkRepo { return &BookmarkRepo{pg: pg} }

// Create inserts a new bookmark. ErrBookmarkExists on (user_id, source_url) collision.
func (r *BookmarkRepo) Create(ctx context.Context, userID, sourceURL, sourceTitle string, excerpt, note *string) (*model.Bookmark, error) {
	b := &model.Bookmark{}
	err := r.pg.Pool.QueryRow(ctx, `
		INSERT INTO bookmarks (user_id, source_url, source_title, excerpt, note)
		VALUES ($1, $2, $3, $4, $5)
		RETURNING id, user_id, source_url, COALESCE(source_title, ''), excerpt, note, created_at`,
		userID, sourceURL, sourceTitle, excerpt, note,
	).Scan(&b.ID, &b.UserID, &b.SourceURL, &b.SourceTitle, &b.Excerpt, &b.Note, &b.CreatedAt)
	if err != nil {
		if strings.Contains(err.Error(), "23505") {
			return nil, ErrBookmarkExists
		}
		return nil, fmt.Errorf("create bookmark: %w", err)
	}
	return b, nil
}

// ListByUser returns all bookmarks for the caller, newest first.
func (r *BookmarkRepo) ListByUser(ctx context.Context, userID string) ([]model.Bookmark, error) {
	rows, err := r.pg.Pool.Query(ctx, `
		SELECT id, user_id, source_url, COALESCE(source_title, ''), excerpt, note, created_at
		FROM bookmarks WHERE user_id = $1 ORDER BY created_at DESC`, userID)
	if err != nil {
		return nil, fmt.Errorf("query bookmarks: %w", err)
	}
	defer rows.Close()
	out := []model.Bookmark{}
	for rows.Next() {
		var b model.Bookmark
		if err := rows.Scan(&b.ID, &b.UserID, &b.SourceURL, &b.SourceTitle,
			&b.Excerpt, &b.Note, &b.CreatedAt); err != nil {
			return nil, fmt.Errorf("scan bookmark: %w", err)
		}
		out = append(out, b)
	}
	return out, rows.Err()
}

// CountByUser is used by the plan-limit enforcer.
func (r *BookmarkRepo) CountByUser(ctx context.Context, userID string) (int, error) {
	var n int
	err := r.pg.Pool.QueryRow(ctx, `SELECT COUNT(*) FROM bookmarks WHERE user_id = $1`, userID).Scan(&n)
	if err != nil {
		return 0, fmt.Errorf("count bookmarks: %w", err)
	}
	return n, nil
}

// Delete removes a bookmark belonging to the caller.
func (r *BookmarkRepo) Delete(ctx context.Context, id, userID string) error {
	tag, err := r.pg.Pool.Exec(ctx,
		`DELETE FROM bookmarks WHERE id = $1 AND user_id = $2`, id, userID)
	if err != nil {
		return fmt.Errorf("delete bookmark: %w", err)
	}
	if tag.RowsAffected() == 0 {
		return ErrBookmarkNotFound
	}
	return nil
}

// FindByID returns one bookmark (used for the owner-check path).
func (r *BookmarkRepo) FindByID(ctx context.Context, id string) (*model.Bookmark, error) {
	b := &model.Bookmark{}
	err := r.pg.Pool.QueryRow(ctx, `
		SELECT id, user_id, source_url, COALESCE(source_title, ''), excerpt, note, created_at
		FROM bookmarks WHERE id = $1`, id,
	).Scan(&b.ID, &b.UserID, &b.SourceURL, &b.SourceTitle, &b.Excerpt, &b.Note, &b.CreatedAt)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			return nil, ErrBookmarkNotFound
		}
		return nil, fmt.Errorf("find bookmark: %w", err)
	}
	return b, nil
}