export type Severity = 'error' | 'warning';
export type Target = 'source' | 'SKILL.md' | 'AGENTS.md' | 'MCP-SERVER.md';
export type MaybeTarget = Target | 'auto';
export type ExitCode = 0 | 1 | 2 | 3 | 4;

export type Diagnostic = {
	code: string;
	message: string;
	severity: Severity;
	path?: string;
	rule?: string;
	schema?: string;
	instancePath?: string;
};

export type Globals = {
	json: boolean;
	quiet: boolean;
	verbose: boolean;
	color: boolean;
	noNext: boolean;
};

export type Artifact = {
	path?: string;
	kind: string;
	target?: Target | 'source';
	digest?: string;
};

export type NextAction = {
	id: string;
	required: boolean;
	reason: string;
	command?: string;
	external?: string;
};

export type ExtractResult =
	| { kind: 'ok'; frontmatter: unknown; body: string; normalizedText: string }
	| { kind: 'no-frontmatter'; body: string; normalizedText: string }
	| { kind: 'error'; code: string; message: string };

export type CommandResult = Record<string, unknown> & {
	ok: boolean;
	command: string;
	exitCode: ExitCode;
	summary: string;
	artifacts: Artifact[];
	diagnostics: Diagnostic[];
	nextActions: NextAction[];
};

export const EXIT = {
	ok: 0 as const,
	failure: 1 as const,
	usage: 2 as const,
	io: 3 as const,
	internal: 4 as const,
};

export const TARGETS: Target[] = ['source', 'SKILL.md', 'AGENTS.md', 'MCP-SERVER.md'];
export const MDA_EXTENDED = [
	'doc-id',
	'title',
	'version',
	'requires',
	'depends-on',
	'author',
	'tags',
	'created-date',
	'updated-date',
	'relationships',
];
export const TARGET_ORDER: Target[] = ['SKILL.md', 'AGENTS.md', 'MCP-SERVER.md'];
export const MCP_BOUNDARY = '\n--MDA-FILE-BOUNDARY--\n';

export function commandResult(
	ok: boolean,
	command: string,
	exitCode: ExitCode,
	diagnostics: Diagnostic[],
	extra: Record<string, unknown> = {},
): CommandResult {
	const stableDiagnostics = diagnostics.map(stabilizeDiagnosticCode);
	return {
		ok,
		command,
		exitCode,
		summary: ok ? `${command} completed` : `${command} failed`,
		artifacts: [],
		diagnostics: stableDiagnostics,
		nextActions: [],
		...extra,
	};
}

export function diag(code: string, message: string, extra: Partial<Diagnostic> = {}): Diagnostic {
	return { code, message, severity: 'error', ...extra };
}

function stabilizeDiagnosticCode(diagnostic: Diagnostic): Diagnostic {
	return { ...diagnostic, code: stableDiagnosticCode(diagnostic.code) };
}

function stableDiagnosticCode(code: string): string {
	if (/^(input|schema|integrity|signature|trust_policy|sigstore|rekor|did_web|llmix|release|compat|filesystem|conformance)\./.test(code)) {
		return code;
	}
	const mapped = DIAGNOSTIC_CODE_MAP[code];
	if (mapped) return mapped;
	return `input.${
		code
			.replace(/[^a-zA-Z0-9]+/g, '_')
			.replace(/^_+|_+$/g, '')
			.toLowerCase() || 'unknown'
	}`;
}

const DIAGNOSTIC_CODE_MAP: Record<string, string> = {
	'usage-error': 'input.usage',
	'invalid-encoding': 'input.invalid_encoding',
	'unterminated-frontmatter': 'input.unterminated_frontmatter',
	'frontmatter-yaml-parse-error': 'input.frontmatter_yaml_parse',
	'missing-required-frontmatter': 'input.missing_required_frontmatter',
	'missing-required-body': 'input.missing_required_body',
	'invalid-json': 'input.invalid_json',
	'io-error': 'filesystem.io',
	'rollback-error': 'filesystem.rollback',
	'schema-validation-error': 'schema.validation',
	'relationship-footnote-json-parse-error': 'schema.relationship_footnote_json_parse',
	'missing-required-sidecar': 'integrity.missing_required_sidecar',
	'missing-required-integrity': 'integrity.missing_required',
	'unsupported-integrity-algorithm': 'integrity.unsupported_algorithm',
	'integrity-mismatch': 'integrity.mismatch',
	'missing-required-signature': 'signature.missing_required',
	'signature-digest-mismatch': 'signature.digest_mismatch',
	'signature-verification-unavailable': 'signature.verification_unavailable',
	'signing-unavailable': 'signature.signing_unavailable',
	'trust-policy-violation': 'trust_policy.violation',
	'no-trusted-signature': 'trust_policy.no_trusted_signature',
	'insufficient-trusted-signatures': 'trust_policy.insufficient_trusted_signatures',
	'fixture-missing': 'conformance.fixture_missing',
	'conformance-manifest-invalid': 'conformance.manifest_invalid',
	'extraction-mismatch': 'conformance.extraction_mismatch',
	'expected-error-mismatch': 'conformance.expected_error_mismatch',
	'compile-fixture-unavailable': 'conformance.compile_fixture_unavailable',
	'internal-error': 'input.internal_error',
};

export function usage(command: string, message: string, extra: Record<string, unknown> = {}): CommandResult {
	return commandResult(false, command, EXIT.usage, [diag('usage-error', message)], {
		summary: `${command} usage error`,
		nextActions: [
			{
				id: 'show-help',
				required: true,
				reason: 'Review command usage',
				command: 'mda --help',
			},
		],
		...extra,
	});
}

export function ioError(command: string, message: string, extra: Record<string, unknown> = {}): CommandResult {
	return commandResult(false, command, EXIT.io, [diag('io-error', message)], {
		summary: `${command} IO error`,
		nextActions: [
			{
				id: 'fix-filesystem',
				required: true,
				reason: 'Fix the filesystem path or permissions and retry',
				command: `mda ${command}`,
			},
		],
		...extra,
	});
}