package tenant

import (
	"context"
	"database/sql"
)

func (q *Queries) ListReactions(ctx context.Context, postSlug string) ([]Reaction, error) {
	rows, err := q.db.QueryContext(ctx, `SELECT id, user_id, anon_id, post_slug, emoji, created_at
		FROM reactions WHERE post_slug = ?`, postSlug)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var reactions []Reaction
	for rows.Next() {
		r, err := scanReaction(rows)
		if err != nil {
			return nil, err
		}
		reactions = append(reactions, r)
	}
	return reactions, rows.Err()
}

func (q *Queries) GetReactionCounts(ctx context.Context, postSlug string) (map[string]int, error) {
	rows, err := q.db.QueryContext(ctx, `SELECT emoji, COUNT(*) as count FROM reactions WHERE post_slug = ? GROUP BY emoji`, postSlug)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	counts := make(map[string]int)
	for rows.Next() {
		var emoji string
		var count int64
		if err := rows.Scan(&emoji, &count); err != nil {
			return nil, err
		}
		counts[emoji] = int(count)
	}
	return counts, rows.Err()
}

func (q *Queries) ToggleReaction(ctx context.Context, userID, anonID, postSlug, emoji string) (bool, error) {
	var exists bool

	if userID != "" {
		var dummy int64
		err := q.db.QueryRowContext(ctx, `SELECT 1 FROM reactions WHERE user_id = ? AND post_slug = ? AND emoji = ?`,
			userID, postSlug, emoji).Scan(&dummy)
		exists = err == nil
	} else if anonID != "" {
		var dummy int64
		err := q.db.QueryRowContext(ctx, `SELECT 1 FROM reactions WHERE anon_id = ? AND post_slug = ? AND emoji = ?`,
			anonID, postSlug, emoji).Scan(&dummy)
		exists = err == nil
	} else {
		return false, nil
	}

	if !exists {
		if userID != "" {
			_, err := q.db.ExecContext(ctx, `INSERT INTO reactions (user_id, post_slug, emoji) VALUES (?, ?, ?)`,
				userID, postSlug, emoji)
			return true, err
		}
		_, err := q.db.ExecContext(ctx, `INSERT INTO reactions (anon_id, post_slug, emoji) VALUES (?, ?, ?)`,
			anonID, postSlug, emoji)
		return true, err
	}

	if userID != "" {
		_, err := q.db.ExecContext(ctx, `DELETE FROM reactions WHERE user_id = ? AND post_slug = ? AND emoji = ?`,
			userID, postSlug, emoji)
		return false, err
	}
	_, err := q.db.ExecContext(ctx, `DELETE FROM reactions WHERE anon_id = ? AND post_slug = ? AND emoji = ?`,
		anonID, postSlug, emoji)
	return false, err
}

func (q *Queries) GetUserReactions(ctx context.Context, userID, postSlug string) ([]string, error) {
	rows, err := q.db.QueryContext(ctx, `SELECT emoji FROM reactions WHERE user_id = ? AND post_slug = ?`, userID, postSlug)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var emojis []string
	for rows.Next() {
		var emoji string
		if err := rows.Scan(&emoji); err != nil {
			return nil, err
		}
		emojis = append(emojis, emoji)
	}
	return emojis, rows.Err()
}

func (q *Queries) GetAnonReactions(ctx context.Context, anonID, postSlug string) ([]string, error) {
	rows, err := q.db.QueryContext(ctx, `SELECT emoji FROM reactions WHERE anon_id = ? AND post_slug = ?`, anonID, postSlug)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var emojis []string
	for rows.Next() {
		var emoji string
		if err := rows.Scan(&emoji); err != nil {
			return nil, err
		}
		emojis = append(emojis, emoji)
	}
	return emojis, rows.Err()
}

func (q *Queries) HasUserReacted(ctx context.Context, userID, postSlug string) (bool, error) {
	var dummy int64
	err := q.db.QueryRowContext(ctx, `SELECT 1 FROM reactions WHERE user_id = ? AND post_slug = ? LIMIT 1`,
		userID, postSlug).Scan(&dummy)
	if err == sql.ErrNoRows {
		return false, nil
	}
	if err != nil {
		return false, nil
	}
	return true, nil
}

func (q *Queries) HasAnonReacted(ctx context.Context, anonID, postSlug string) (bool, error) {
	var dummy int64
	err := q.db.QueryRowContext(ctx, `SELECT 1 FROM reactions WHERE anon_id = ? AND post_slug = ? LIMIT 1`,
		anonID, postSlug).Scan(&dummy)
	if err == sql.ErrNoRows {
		return false, nil
	}
	if err != nil {
		return false, nil
	}
	return true, nil
}

func scanReaction(s scanner) (Reaction, error) {
	var r Reaction
	var userID, anonID, createdAt sql.NullString

	err := s.Scan(&r.ID, &userID, &anonID, &r.PostSlug, &r.Emoji, &createdAt)
	if err != nil {
		return r, err
	}

	r.UserID = userID.String
	r.AnonID = anonID.String
	r.CreatedAt = parseTime(createdAt.String)
	return r, nil
}