import { BrowserView, Utils } from "electrobun/bun";
import type { AppRPC } from "../shared/rpc";
import { effectiveConcurrency, type Result } from "../shared/types";
import { readFileText, writeFileText, type EditManager } from "./edits";
import type { SessionRegistry } from "./fs/registry";
import { SftpProvider } from "./fs/sftp";
import type { ConnectionStore } from "./store/connections";
import type { SettingsStore } from "./store/settings";
import type { TransferEngine } from "./transfers/engine";
import { removeRecursive } from "./transfers/walk";

// SFTP ops can be slow (big listings, recursive deletes) — the 1s electrobun
// default would cut them off.
const MAX_REQUEST_TIME_MS = 10 * 60_000;

export interface AppDeps {
	registry: SessionRegistry;
	engine: TransferEngine;
	store: ConnectionStore;
	settings: SettingsStore;
	edits: EditManager;
	/** Assigned after the rpc object exists (it needs rpc.send). */
	events: {
		sessionClosed: (info: { sessionId: string; reason: string }) => void;
		connectionsChanged: () => void;
	};
}

async function wrap<T extends object>(fn: () => Promise<T> | T): Promise<Result<T>> {
	try {
		return { ok: true, ...(await fn()) };
	} catch (error) {
		return { ok: false, error: error instanceof Error ? error.message : String(error) };
	}
}

export function createAppRPC({ registry, engine, store, settings, edits, events }: AppDeps) {
	return BrowserView.defineRPC<AppRPC>({
		maxRequestTime: MAX_REQUEST_TIME_MS,
		handlers: {
			requests: {
				// ---- sessions ----
				connect: ({ config }) =>
					wrap(async () => {
						let sessionId = "";
						const provider = await SftpProvider.connect(config, (reason) => {
							if (!sessionId) return;
							registry.drop(sessionId);
							engine.failSession(sessionId, reason);
							edits.stopForSession(sessionId);
							events.sessionClosed({ sessionId, reason });
						});
						sessionId = registry.add(provider);
						const homeDir = await provider.homeDir();
						console.log(`[rpc] connected ${sessionId} -> ${config.username}@${config.host}`);
						return { sessionId, homeDir, fsKey: provider.fsKey };
					}),

				disconnect: ({ sessionId }) =>
					wrap(async () => {
						edits.stopForSession(sessionId);
						await registry.remove(sessionId);
						console.log(`[rpc] disconnected ${sessionId}`);
						return {};
					}),

				// ---- filesystem ----
				listDir: ({ sessionId, path }) =>
					wrap(async () => {
						const fs = registry.get(sessionId);
						const dir = fs.normalize(path ?? (await fs.homeDir()));
						return { path: dir, entries: await fs.list(dir) };
					}),

				mkdir: ({ sessionId, path }) =>
					wrap(async () => {
						await registry.get(sessionId).mkdir(path);
						return {};
					}),

				createFile: ({ sessionId, path }) =>
					wrap(async () => {
						await registry.get(sessionId).createEmptyFile(path);
						return {};
					}),

				rename: ({ sessionId, oldPath, newPath }) =>
					wrap(async () => {
						await registry.get(sessionId).rename(oldPath, newPath);
						return {};
					}),

				deleteEntries: ({ sessionId, entries }) =>
					wrap(async () => {
						const fs = registry.get(sessionId);
						for (const { path, type } of entries) {
							await removeRecursive(fs, path, type);
						}
						return {};
					}),

				chmod: ({ sessionId, paths, mode }) =>
					wrap(async () => {
						const fs = registry.get(sessionId);
						for (const path of paths) {
							await fs.chmod(path, mode);
						}
						return {};
					}),

				// ---- transfers ----
				enqueueTransfers: (params) =>
					wrap(async () => ({ jobIds: engine.enqueue(params) })),

				cancelTransfer: ({ jobId }) =>
					wrap(async () => {
						engine.cancel(jobId);
						return {};
					}),

				dismissTransfer: ({ jobId }) =>
					wrap(async () => {
						engine.dismiss(jobId);
						return {};
					}),

				// ---- connection store ----
				getConnections: () => wrap(async () => ({ store: await store.load() })),

				upsertConnection: ({ connection }) =>
					wrap(async () => {
						const id = await store.upsertConnection(connection);
						events.connectionsChanged();
						return { id };
					}),

				deleteConnection: ({ id }) =>
					wrap(async () => {
						await store.deleteConnection(id);
						events.connectionsChanged();
						return {};
					}),

				upsertFolder: ({ folder }) =>
					wrap(async () => {
						const id = await store.upsertFolder(folder);
						events.connectionsChanged();
						return { id };
					}),

				deleteFolder: ({ id }) =>
					wrap(async () => {
						await store.deleteFolder(id);
						events.connectionsChanged();
						return {};
					}),

				// ---- settings ----
				getSettings: () => wrap(async () => ({ settings: await settings.load() })),

				saveSettings: ({ settings: next }) =>
					wrap(async () => {
						await settings.save(next);
						engine.setConcurrency(effectiveConcurrency(next));
						return {};
					}),

				// ---- file editing ----
				readFile: ({ sessionId, path }) =>
					wrap(async () => ({
						content: await readFileText(registry.get(sessionId), path),
					})),

				writeFile: ({ sessionId, path, content }) =>
					wrap(async () => {
						await writeFileText(registry.get(sessionId), path, content);
						return {};
					}),

				editExternal: ({ sessionId, path }) =>
					wrap(() => edits.editExternal(sessionId, path)),

				pickEditorApp: () =>
					wrap(async () => {
						const picked = await Utils.openFileDialog({
							startingFolder: "/Applications",
							allowedFileTypes: "app",
							canChooseFiles: true,
							canChooseDirectory: false,
							allowsMultipleSelection: false,
						});
						const path = picked.find((p) => p.trim().length > 0) ?? null;
						return { path };
					}),

				getEditLeftovers: () =>
					wrap(async () => ({ names: await edits.listLeftovers() })),

				clearEditLeftovers: () =>
					wrap(async () => {
						await edits.clearLeftovers();
						return {};
					}),
			},
		},
	});
}