/**
 * Structured logger powered by LogTape (@logtape/logtape).
 *
 * Two tiers of logging:
 * - **logger**  — general-purpose logging (suppressed in production for security)
 *   - Dev:  `trace`, `debug`, `info`, `warn`, `error`  (configurable via PUBLIC_APP_LOG_LEVEL)
 *   - Prod: `info` by default (or what PUBLIC_APP_LOG_LEVEL says)
 * - **inspector** — error-only logging, ALWAYS active (never suppressed).
 *   Use for security-critical events that must appear in the browser
 *   developer console (e.g. auth failures, API errors).
 *
 * API (100 % backward compatible):
 *   logger.info('message', arg1, …)
 *   logger.error('Failed:', err)
 *   inspector.error('auth failure', uid)   // always visible
 */
import { configureSync, getConfig, getConsoleSink, withFilter, getLogger } from '@logtape/logtape';
import type { LogLevel } from '@logtape/logtape';

// ---------------------------------------------------------------------------
// LogTape configuration (idempotent — uses getConfig() not a local flag)
// ---------------------------------------------------------------------------

/**
 * Resolve the log level lazily (not at module-eval time).
 *
 * import.meta.env is undefined when Vite loads vite.config.ts, so we
 * must not read it at the top level.  Deferring to first use ensures
 * Vite has finished initialising by the time we read it.
 */
function resolveLogLevel(): LogLevel {
	const env = import.meta.env as Record<string, string | boolean | undefined> | undefined;
	const isDev = env?.DEV ?? (typeof process !== 'undefined' && process.env?.NODE_ENV !== 'production');
	const configured = env?.PUBLIC_APP_LOG_LEVEL as string | undefined;
	return (configured || (isDev ? 'trace' : 'info')) as LogLevel;
}

function ensureConfigured() {
	// Vite evaluates the config module twice during build (SSR + client).
	// A local `_configured` boolean resets between evaluations, so we
	// rely on LogTape's own global state instead.
	if (getConfig() !== null) return;
	configureSync({
		sinks: {
			console: getConsoleSink(),
			errorsOnly: withFilter(getConsoleSink(), 'error'),
		},
		loggers: [
			{
				category: ['supra-app'],
				sinks: ['console'],
				lowestLevel: resolveLogLevel(),
			},
			{
				category: ['supra-app', 'inspector'],
				sinks: ['errorsOnly'],
				lowestLevel: 'error',
			},
			{
				category: ['logtape', 'meta'],
				sinks: ['console'],
				lowestLevel: 'error',
			},
		],
	});
}

// ---------------------------------------------------------------------------
// Internal LogTape loggers (lazy-init)
// ---------------------------------------------------------------------------

function getBaseLogger() {
	ensureConfigured();
	return getLogger(['supra-app']);
}

function getInspectorLogger() {
	ensureConfigured();
	return getLogger(['supra-app', 'inspector']);
}

// ---------------------------------------------------------------------------
// ---------------------------------------------------------------------------

function isRecord(v: unknown): v is Record<string, unknown> {
	return typeof v === 'object' && v !== null && !(v instanceof Error) && !Array.isArray(v);
}

/**
 * Convert variadic args into a flat message string + optional extras.
 *
 * Patterns handled:
 *   logger.info('text')                     → message, no props
 *   logger.info('text', obj)                → message, obj as props     if obj is a plain Record
 *   logger.info('text', error)              → error overload
 *   logger.info('text', arg1, arg2, …)      → concatenated message
 */
function normalize(
	args: unknown[],
): { message: string; error?: Error; properties?: Record<string, unknown> } {
	if (args.length === 0) return { message: '' };

	const first = args[0];
	if (args.length === 1) {
		if (first instanceof Error) return { message: first.message, error: first };
		return { message: String(first) };
	}

	if (args.length === 2 && isRecord(args[1])) {
		return { message: String(first), properties: args[1] };
	}

	// error overload: logger.warn(msg, error) / logger.error('msg', err)
	if (args.length === 2 && args[1] instanceof Error) {
		return { message: String(first), error: args[1] as Error };
	}

	// multi-arg: concatenate
	return {
		message: args.map((a) => (typeof a === 'object' ? safeStringify(a) : String(a))).join(' '),
	};
}

function safeStringify(v: unknown): string {
	if (v instanceof Error) return `${v.name}: ${v.message}`;
	try {
		return JSON.stringify(v);
	} catch {
		return String(v);
	}
}

// ---------------------------------------------------------------------------
// ---------------------------------------------------------------------------
// ---------------------------------------------------------------------------

export const logger = {
	trace(...args: unknown[]) {
		const { message } = normalize(args);
		getBaseLogger().trace(message);
	},

	debug(...args: unknown[]) {
		const { message, properties } = normalize(args);
		if (properties) {
			getBaseLogger().debug(message, properties);
		} else {
			getBaseLogger().debug(message);
		}
	},

	info(...args: unknown[]) {
		const { message, properties } = normalize(args);
		if (properties) {
			getBaseLogger().info(message, properties);
		} else {
			getBaseLogger().info(message);
		}
	},

	warn(...args: unknown[]) {
		const { message, error, properties } = normalize(args);
		if (properties) {
			getBaseLogger().warn(message, properties);
		} else if (error) {
			getBaseLogger().warn(message, error);
		} else {
			getBaseLogger().warn(message);
		}
	},

	error(...args: unknown[]) {
		const { message, error, properties } = normalize(args);
		if (error && properties) {
			getBaseLogger().error(error, properties);
		} else if (error) {
			getBaseLogger().error(error);
		} else if (properties) {
			getBaseLogger().error(message, properties);
		} else {
			getBaseLogger().error(message);
		}
	},
};

// ---------------------------------------------------------------------------
// ---------------------------------------------------------------------------
// ---------------------------------------------------------------------------

/**
 * Inspector logger — always active, error-only, never suppressed.
 * Messages are written via the same LogTape infrastructure but on a
 * separate category (supra-app → inspector) whose sink is hard-filtered to
 * `error` / `fatal` so security-sensitive events are always visible.
 */
export const inspector = {
	error(...args: unknown[]) {
		const { message, error, properties } = normalize(args);
		if (error && properties) {
			getInspectorLogger().error(error, properties);
		} else if (error) {
			getInspectorLogger().error(error);
		} else if (properties) {
			getInspectorLogger().error(message, properties);
		} else {
			getInspectorLogger().error(message);
		}
	},

	warn(...args: unknown[]) {
		const { message, error } = normalize(args);
		// inspector only logs errors; escalate to error level
		if (error) {
			getInspectorLogger().error(error);
		} else if (message) {
			getInspectorLogger().error(message);
		}
	},

	info(...args: unknown[]) {
		const { message } = normalize(args);
		// promote to error so it passes the filter
		if (message) getInspectorLogger().error(message);
	},
};