/**
 * Schema export endpoint for CLI sync
 *
 * GET /_emdash/api/schema - Export full schema (requires schema:read permission)
 *
 * This endpoint is used by:
 * - CLI `emdash types` to fetch schema and generate types
 * - Local dev server to sync schema from remote
 * - CI/CD to detect schema drift
 */

import type { APIRoute } from "astro";
import { hashString } from "emdash";

import { requirePerm } from "#api/authorize.js";
import { apiSuccess, handleError, requireDb } from "#api/error.js";
import { SchemaRegistry } from "#schema/registry.js";
import { generateTypeScript, uniqueInterfaceNames } from "#schema/zod-generator.js";

export const prerender = false;

export const GET: APIRoute = async ({ request, locals }) => {
	const { emdash, user } = locals;

	const dbErr = requireDb(emdash?.db);
	if (dbErr) return dbErr;

	const denied = requirePerm(user, "schema:read");
	if (denied) return denied;

	try {
		const registry = new SchemaRegistry(emdash.db);

		// Get all collections with their fields
		const collections = await registry.listCollections();
		const collectionsWithFields = await Promise.all(
			collections.map(async (c) => {
				const fields = await registry.listFields(c.id);
				return { ...c, fields };
			}),
		);

		// Check for format parameter
		const url = new URL(request.url);
		const format = url.searchParams.get("format");

		if (format === "typescript") {
			// Generate TypeScript definitions. Singularizing slugs can collapse
			// distinct collections onto the same interface name, so resolve names
			// up front to keep every emitted interface unique (`book` + `books`
			// would otherwise both emit `Book`).
			const interfaceNames = uniqueInterfaceNames(collectionsWithFields);
			const types = collectionsWithFields
				.map((c) => generateTypeScript(c, interfaceNames.get(c.slug)))
				.join("\n\n");

			const header = `// Generated by EmDash CLI
// Do not edit manually - run \`emdash types\` to regenerate

import type { PortableTextBlock } from "emdash";

`;

			return new Response(header + types, {
				status: 200,
				headers: {
					"Content-Type": "text/typescript",
					"Cache-Control": "private, no-store",
				},
			});
		}

		// Default: JSON format
		const schemaExport = {
			collections: collectionsWithFields.map((c) => ({
				slug: c.slug,
				label: c.label,
				labelSingular: c.labelSingular,
				description: c.description,
				icon: c.icon,
				supports: c.supports,
				fields: c.fields.map((f) => ({
					slug: f.slug,
					label: f.label,
					type: f.type,
					required: f.required,
					unique: f.unique,
					defaultValue: f.defaultValue,
					validation: f.validation,
					widget: f.widget,
					options: f.options,
				})),
			})),
		};

		const version = await hashString(JSON.stringify(schemaExport));

		const response = apiSuccess({
			...schemaExport,
			version,
		});
		response.headers.set("X-Schema-Version", version);
		return response;
	} catch (error) {
		return handleError(error, "Schema export failed", "SCHEMA_EXPORT_ERROR");
	}
};