// Sends Discord webhook notifications for place-level events (access granted/denied, reader
// arm/disarm, reader enable/disable). Uses the runtime's built-in fetch() - no extra dependency.
//
// Each place has its own webhook config (see migrations/0009_discord_webhooks.sql):
//   webhookUrl            - the Discord webhook URL to POST to. If falsy, notifications are skipped.
//   webhookContent        - optional plain-text `content` sent alongside the embed (e.g. "@here" or
//                            a role/user mention). Purely cosmetic - never affects delivery logic.
//   webhookAccessGranted  - toggle for access_granted events
//   webhookAccessDenied   - toggle for access_denied events
//   webhookReaderArm      - toggle for both reader_armed and reader_disarmed events
//   webhookReaderEnable   - toggle for both reader_enabled and reader_disabled events
//
// Sending is entirely fire-and-forget: failures are logged but never thrown, so a broken/rate-limited
// webhook can never affect scan results or the dashboard's own API responses.

// Discord embed side colors (decimal), matching the dashboard's --success/--danger/--accent palette.
const COLORS = {
	GREEN: 0x3ecf8e,
	RED: 0xe5484d,
	BLUE: 0x4f7cff,
	ORANGE: 0xf5a623
};

// Maps each event type to the place column that gates it, plus how to render its embed.
const EVENT_CONFIG = {
	access_granted: {
		toggleColumn: 'webhookAccessGranted',
		title: '✅ Access granted',
		color: COLORS.GREEN
	},
	access_denied: {
		toggleColumn: 'webhookAccessDenied',
		title: '⛔ Access denied',
		color: COLORS.RED
	},
	reader_armed: {
		toggleColumn: 'webhookReaderArm',
		title: '🔒 Reader armed',
		color: COLORS.BLUE
	},
	reader_disarmed: {
		toggleColumn: 'webhookReaderArm',
		title: '🔓 Reader disarmed',
		color: COLORS.ORANGE
	},
	reader_enabled: {
		toggleColumn: 'webhookReaderEnable',
		title: '🟢 Reader enabled',
		color: COLORS.GREEN
	},
	reader_disabled: {
		toggleColumn: 'webhookReaderEnable',
		title: '🔴 Reader disabled',
		color: COLORS.RED
	}
};

// Builds the Discord embed `fields` array from a plain object, skipping any nullish values.
// Values are stringified and truncated to Discord's 1024-char field value limit.
function buildFields(data) {
	return Object.entries(data)
		.filter(([, value]) => value !== undefined && value !== null && value !== '')
		.map(([name, value]) => ({
			name,
			value: String(value).slice(0, 1024),
			inline: true
		}));
}

// POSTs a raw payload to a Discord webhook URL using the runtime's built-in fetch(). Returns
// `{ ok: true }` on a 2xx response, or `{ ok: false, message }` otherwise. Never throws.
async function postToDiscord(webhookUrl, payload) {
	try {
		const res = await fetch(webhookUrl, {
			method: 'POST',
			headers: { 'Content-Type': 'application/json' },
			body: JSON.stringify(payload)
		});
		if (!res.ok) {
			const body = await res.text().catch(() => '');
			return { ok: false, message: `Discord responded with ${res.status}${body ? `: ${body}` : ''}` };
		}
		return { ok: true };
	} catch (err) {
		return { ok: false, message: err.message };
	}
}

// Fires a Discord webhook for `eventType` on behalf of `place`, if it has a webhook URL configured
// and has that event type's toggle enabled. `fields` is a plain object of embed field name -> value
// (e.g. { Reader: 'Front Door', User: '123456' }). Never throws - logs and resolves on any failure.
async function sendPlaceWebhook(place, eventType, fields = {}) {
	const config = EVENT_CONFIG[eventType];
	if (!config) {
		console.error(`Unknown webhook event type: ${eventType}`);
		return;
	}

	if (!place || !place.webhookUrl || !place[config.toggleColumn]) {
		return; // No webhook configured, or this event type isn't enabled for this place.
	}

	const embed = {
		title: config.title,
		color: config.color,
		fields: buildFields(fields),
		footer: { text: place.name || place.id },
		timestamp: new Date().toISOString()
	};

	const payload = { embeds: [embed] };
	if (place.webhookContent) {
		payload.content = String(place.webhookContent);
	}

	const result = await postToDiscord(place.webhookUrl, payload);
	if (!result.ok) {
		console.error(`Discord webhook for place ${place.id} failed: ${result.message}`);
	}
}

// Sends a one-off test embed straight to `webhookUrl` (bypassing the place's toggles, since the
// user is explicitly asking to test it), optionally including `content`. Used by the dashboard's
// "Send test" button. Returns `{ ok, message }` so the caller can surface any failure to the user.
async function sendTestWebhook(webhookUrl, content) {
	if (!webhookUrl) {
		return { ok: false, message: 'No webhook URL configured' };
	}

	const payload = {
		embeds: [{
			title: '🔔 Test notification',
			description: 'This is a test alert from NOTXCS. If you can see this, your webhook is configured correctly.',
			color: COLORS.BLUE,
			timestamp: new Date().toISOString()
		}]
	};
	if (content) {
		payload.content = String(content);
	}

	return postToDiscord(webhookUrl, payload);
}

module.exports = { sendPlaceWebhook, sendTestWebhook, EVENT_CONFIG };