package bot

import (
	"context"
	"database/sql"
	"encoding/json"
	"fmt"
	"strings"
	"time"
)

// ConfessConfig: "channel_id" is where anonymous confessions land.
type ConfessConfig struct {
	ChannelID string `json:"channel_id"`
}

// ConfessBot watches for /confess messages, deletes the original, reposts anonymously.
func ConfessBot(ctx context.Context, db *sql.DB, raw json.RawMessage, send SendMessageFunc) {
	var cfg ConfessConfig
	if err := json.Unmarshal(raw, &cfg); err != nil || cfg.ChannelID == "" {
		return
	}

	lastID := ""
	ticker := time.NewTicker(10 * time.Second)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
			confessPoll(db, cfg.ChannelID, &lastID, send)
		}
	}
}

func confessPoll(db *sql.DB, targetChannel string, lastID *string, send SendMessageFunc) {
	q := `SELECT id, channel_id, content FROM messages
		WHERE content ILIKE '/confess%' AND bot_id IS NULL
		ORDER BY created_at ASC LIMIT 10`
	if *lastID != "" {
		q = `SELECT id, channel_id, content FROM messages
			WHERE content ILIKE '/confess%' AND bot_id IS NULL AND created_at::text > (SELECT created_at::text FROM messages WHERE id = $1)
			ORDER BY created_at ASC LIMIT 10`
	}

	var rows *sql.Rows
	var err error
	if *lastID != "" {
		rows, err = db.QueryContext(context.Background(), q, *lastID)
	} else {
		rows, err = db.QueryContext(context.Background(), q)
	}
	if err != nil {
		return
	}
	defer rows.Close()

	for rows.Next() {
		var id, channelID, content string
		if err := rows.Scan(&id, &channelID, &content); err != nil {
			continue
		}
		*lastID = id

		// Strip "/confess" prefix
		text := strings.TrimSpace(strings.TrimPrefix(content, "/confess"))
		if text == "" {
			continue
		}

		// Delete the original message
		db.ExecContext(context.Background(), `DELETE FROM messages WHERE id = $1`, id)

		// Repost anonymously
		send(targetChannel, fmt.Sprintf("🕵️ **anonymous confession:** %s", text))
	}
}