/**
 * Main entry point for the coding agent CLI.
 *
 * This file handles CLI argument parsing and translates them into
 * createAgentSession() options. The SDK does the heavy lifting.
 */

import { createInterface } from "node:readline";
import { type ImageContent, modelsAreEqual } from "@earendil-works/pi-ai";
import { ProcessTerminal, setKeybindings, TUI } from "@earendil-works/pi-tui";
import chalk from "chalk";
import { type Args, type Mode, parseArgs, printHelp } from "./cli/args.ts";
import { processFileArguments } from "./cli/file-processor.ts";
import { buildInitialMessage } from "./cli/initial-message.ts";
import { listModels } from "./cli/list-models.ts";
import { selectSession } from "./cli/session-picker.ts";
import { ENV_SESSION_DIR, expandTildePath, getAgentDir, getPackageDir, VERSION } from "./config.ts";
import { type CreateAgentSessionRuntimeFactory, createAgentSessionRuntime } from "./core/agent-session-runtime.ts";
import {
	type AgentSessionRuntimeDiagnostic,
	createAgentSessionFromServices,
	createAgentSessionServices,
} from "./core/agent-session-services.ts";
import { formatNoModelsAvailableMessage } from "./core/auth-guidance.ts";
import { AuthStorage } from "./core/auth-storage.ts";
import { exportFromFile } from "./core/export-html/index.ts";
import { emitProjectTrustEvent } from "./core/extensions/runner.ts";
import type { ExtensionFactory, LoadExtensionsResult, ProjectTrustContext } from "./core/extensions/types.ts";
import { configureHttpDispatcher } from "./core/http-dispatcher.ts";
import { KeybindingsManager } from "./core/keybindings.ts";
import type { ModelRegistry } from "./core/model-registry.ts";
import { resolveCliModel, resolveModelScope, type ScopedModel } from "./core/model-resolver.ts";
import { restoreStdout, takeOverStdout } from "./core/output-guard.ts";
import type { CreateAgentSessionOptions } from "./core/sdk.ts";
import {
	formatMissingSessionCwdPrompt,
	getMissingSessionCwdIssue,
	MissingSessionCwdError,
	type SessionCwdIssue,
} from "./core/session-cwd.ts";
import { assertValidSessionId, SessionManager } from "./core/session-manager.ts";
import { SettingsManager } from "./core/settings-manager.ts";
import { printTimings, resetTimings, time } from "./core/timings.ts";
import { hasProjectTrustInputs, ProjectTrustStore } from "./core/trust-manager.ts";
import { runMigrations, showDeprecationWarnings } from "./migrations.ts";
import { InteractiveMode, runPrintMode, runRpcMode } from "./modes/index.ts";
import { ExtensionInputComponent } from "./modes/interactive/components/extension-input.ts";
import { ExtensionSelectorComponent } from "./modes/interactive/components/extension-selector.ts";
import { initTheme, stopThemeWatcher } from "./modes/interactive/theme/theme.ts";
import { handleConfigCommand, handlePackageCommand } from "./package-manager-cli.ts";
import { isLocalPath, normalizePath, resolvePath } from "./utils/paths.ts";
import { cleanupWindowsSelfUpdateQuarantine } from "./utils/windows-self-update.ts";

/**
 * Read all content from piped stdin.
 * Returns undefined if stdin is a TTY (interactive terminal).
 */
async function readPipedStdin(): Promise<string | undefined> {
	// If stdin is a TTY, we're running interactively - don't read stdin
	if (process.stdin.isTTY) {
		return undefined;
	}

	return new Promise((resolve) => {
		let data = "";
		process.stdin.setEncoding("utf8");
		process.stdin.on("data", (chunk) => {
			data += chunk;
		});
		process.stdin.on("end", () => {
			resolve(data.trim() || undefined);
		});
		process.stdin.resume();
	});
}

function collectSettingsDiagnostics(
	settingsManager: SettingsManager,
	context: string,
): AgentSessionRuntimeDiagnostic[] {
	return settingsManager.drainErrors().map(({ scope, error }) => ({
		type: "warning",
		message: `(${context}, ${scope} settings) ${error.message}`,
	}));
}

function reportDiagnostics(diagnostics: readonly AgentSessionRuntimeDiagnostic[]): void {
	for (const diagnostic of diagnostics) {
		const color = diagnostic.type === "error" ? chalk.red : diagnostic.type === "warning" ? chalk.yellow : chalk.dim;
		const prefix = diagnostic.type === "error" ? "Error: " : diagnostic.type === "warning" ? "Warning: " : "";
		console.error(color(`${prefix}${diagnostic.message}`));
	}
}

function isTruthyEnvFlag(value: string | undefined): boolean {
	if (!value) return false;
	return value === "1" || value.toLowerCase() === "true" || value.toLowerCase() === "yes";
}

type AppMode = "interactive" | "print" | "json" | "rpc";

function resolveAppMode(parsed: Args, stdinIsTTY: boolean): AppMode {
	if (parsed.mode === "rpc") {
		return "rpc";
	}
	if (parsed.mode === "json") {
		return "json";
	}
	if (parsed.print || !stdinIsTTY) {
		return "print";
	}
	return "interactive";
}

function toPrintOutputMode(appMode: AppMode): Exclude<Mode, "rpc"> {
	return appMode === "json" ? "json" : "text";
}

async function prepareInitialMessage(
	parsed: Args,
	autoResizeImages: boolean,
	stdinContent?: string,
): Promise<{
	initialMessage?: string;
	initialImages?: ImageContent[];
}> {
	if (parsed.fileArgs.length === 0) {
		return buildInitialMessage({ parsed, stdinContent });
	}

	const { text, images } = await processFileArguments(parsed.fileArgs, { autoResizeImages });
	return buildInitialMessage({
		parsed,
		fileText: text,
		fileImages: images,
		stdinContent,
	});
}

/** Result from resolving a session argument */
type ResolvedSession =
	| { type: "path"; path: string } // Direct file path
	| { type: "local"; path: string } // Found in current project
	| { type: "global"; path: string; cwd: string } // Found in different project
	| { type: "not_found"; arg: string }; // Not found anywhere

/**
 * Resolve a session argument to a file path.
 * If it looks like a path, use as-is. Otherwise try to match as session ID prefix.
 */
async function findLocalSessionByExactId(
	sessionId: string,
	cwd: string,
	sessionDir?: string,
): Promise<{ type: "local"; path: string } | undefined> {
	const localSessions = await SessionManager.list(cwd, sessionDir);
	const localMatch = localSessions.find((s) => s.id === sessionId);
	return localMatch ? { type: "local", path: localMatch.path } : undefined;
}

async function resolveSessionPath(sessionArg: string, cwd: string, sessionDir?: string): Promise<ResolvedSession> {
	// If it looks like a file path, resolve it before handing it to the session manager.
	if (sessionArg.includes("/") || sessionArg.includes("\\") || sessionArg.endsWith(".jsonl")) {
		return { type: "path", path: resolvePath(sessionArg, cwd) };
	}

	// Try to match as session ID in current project first
	const localSessions = await SessionManager.list(cwd, sessionDir);
	const localMatch =
		localSessions.find((s) => s.id === sessionArg) ?? localSessions.find((s) => s.id.startsWith(sessionArg));

	if (localMatch) {
		return { type: "local", path: localMatch.path };
	}

	// Try global search across all projects
	const allSessions = await SessionManager.listAll(sessionDir);
	const globalMatch =
		allSessions.find((s) => s.id === sessionArg) ?? allSessions.find((s) => s.id.startsWith(sessionArg));

	if (globalMatch) {
		return { type: "global", path: globalMatch.path, cwd: globalMatch.cwd };
	}

	// Not found anywhere
	return { type: "not_found", arg: sessionArg };
}

/** Prompt user for yes/no confirmation */
async function promptConfirm(message: string): Promise<boolean> {
	return new Promise((resolve) => {
		const rl = createInterface({
			input: process.stdin,
			output: process.stdout,
		});
		rl.question(`${message} [y/N] `, (answer) => {
			rl.close();
			resolve(answer.toLowerCase() === "y" || answer.toLowerCase() === "yes");
		});
	});
}

function validateForkFlags(parsed: Args): void {
	if (!parsed.fork) return;

	const conflictingFlags = [
		parsed.session ? "--session" : undefined,
		parsed.continue ? "--continue" : undefined,
		parsed.resume ? "--resume" : undefined,
		parsed.noSession ? "--no-session" : undefined,
	].filter((flag): flag is string => flag !== undefined);

	if (conflictingFlags.length > 0) {
		console.error(chalk.red(`Error: --fork cannot be combined with ${conflictingFlags.join(", ")}`));
		process.exit(1);
	}
}

function validateSessionIdFlags(parsed: Args): void {
	if (parsed.sessionId === undefined) return;

	const conflictingFlags = [
		parsed.session ? "--session" : undefined,
		parsed.continue ? "--continue" : undefined,
		parsed.resume ? "--resume" : undefined,
		parsed.noSession ? "--no-session" : undefined,
	].filter((flag): flag is string => flag !== undefined);

	if (conflictingFlags.length > 0) {
		console.error(chalk.red(`Error: --session-id cannot be combined with ${conflictingFlags.join(", ")}`));
		process.exit(1);
	}

	try {
		assertValidSessionId(parsed.sessionId);
	} catch (error: unknown) {
		const message = error instanceof Error ? error.message : String(error);
		console.error(chalk.red(`Error: ${message}`));
		process.exit(1);
	}
}

function forkSessionOrExit(sourcePath: string, cwd: string, sessionDir?: string, sessionId?: string): SessionManager {
	try {
		return SessionManager.forkFrom(sourcePath, cwd, sessionDir, { id: sessionId });
	} catch (error: unknown) {
		const message = error instanceof Error ? error.message : String(error);
		console.error(chalk.red(`Error: ${message}`));
		process.exit(1);
	}
}

async function createSessionManager(
	parsed: Args,
	cwd: string,
	sessionDir: string | undefined,
	settingsManager: SettingsManager,
): Promise<SessionManager> {
	if (parsed.noSession || parsed.help || parsed.listModels !== undefined) {
		return SessionManager.inMemory(cwd);
	}

	if (parsed.fork) {
		if (parsed.sessionId) {
			const existingTarget = await findLocalSessionByExactId(parsed.sessionId, cwd, sessionDir);
			if (existingTarget) {
				console.error(chalk.red(`Session already exists with id '${parsed.sessionId}'`));
				process.exit(1);
			}
		}

		const resolved = await resolveSessionPath(parsed.fork, cwd, sessionDir);

		switch (resolved.type) {
			case "path":
			case "local":
			case "global":
				return forkSessionOrExit(resolved.path, cwd, sessionDir, parsed.sessionId);

			case "not_found":
				console.error(chalk.red(`No session found matching '${resolved.arg}'`));
				process.exit(1);
		}
	}

	if (parsed.session) {
		const resolved = await resolveSessionPath(parsed.session, cwd, sessionDir);

		switch (resolved.type) {
			case "path":
			case "local":
				return SessionManager.open(resolved.path, sessionDir);

			case "global": {
				console.log(chalk.yellow(`Session found in different project: ${resolved.cwd}`));
				const shouldFork = await promptConfirm("Fork this session into current directory?");
				if (!shouldFork) {
					console.log(chalk.dim("Aborted."));
					process.exit(0);
				}
				return forkSessionOrExit(resolved.path, cwd, sessionDir);
			}

			case "not_found":
				console.error(chalk.red(`No session found matching '${resolved.arg}'`));
				process.exit(1);
		}
	}

	if (parsed.resume) {
		initTheme(settingsManager.getTheme(), true);
		try {
			const selectedPath = await selectSession(
				(onProgress) => SessionManager.list(cwd, sessionDir, onProgress),
				(onProgress) => SessionManager.listAll(sessionDir, onProgress),
			);
			if (!selectedPath) {
				console.log(chalk.dim("No session selected"));
				process.exit(0);
			}
			return SessionManager.open(selectedPath, sessionDir);
		} finally {
			stopThemeWatcher();
		}
	}

	if (parsed.continue) {
		return SessionManager.continueRecent(cwd, sessionDir);
	}

	if (parsed.sessionId) {
		const existingSession = await findLocalSessionByExactId(parsed.sessionId, cwd, sessionDir);
		if (existingSession) {
			return SessionManager.open(existingSession.path, sessionDir);
		}
	}

	return SessionManager.create(cwd, sessionDir, { id: parsed.sessionId });
}

function buildSessionOptions(
	parsed: Args,
	scopedModels: ScopedModel[],
	hasExistingSession: boolean,
	modelRegistry: ModelRegistry,
	settingsManager: SettingsManager,
): {
	options: CreateAgentSessionOptions;
	cliThinkingFromModel: boolean;
	diagnostics: AgentSessionRuntimeDiagnostic[];
} {
	const options: CreateAgentSessionOptions = {};
	const diagnostics: AgentSessionRuntimeDiagnostic[] = [];
	let cliThinkingFromModel = false;

	// Model from CLI
	// - supports --provider <name> --model <pattern>
	// - supports --model <provider>/<pattern>
	if (parsed.model) {
		const resolved = resolveCliModel({
			cliProvider: parsed.provider,
			cliModel: parsed.model,
			modelRegistry,
		});
		if (resolved.warning) {
			diagnostics.push({ type: "warning", message: resolved.warning });
		}
		if (resolved.error) {
			diagnostics.push({ type: "error", message: resolved.error });
		}
		if (resolved.model) {
			options.model = resolved.model;
			// Allow "--model <pattern>:<thinking>" as a shorthand.
			// Explicit --thinking still takes precedence (applied later).
			if (!parsed.thinking && resolved.thinkingLevel) {
				options.thinkingLevel = resolved.thinkingLevel;
				cliThinkingFromModel = true;
			}
		}
	}

	if (!options.model && scopedModels.length > 0 && !hasExistingSession) {
		// Check if saved default is in scoped models - use it if so, otherwise first scoped model
		const savedProvider = settingsManager.getDefaultProvider();
		const savedModelId = settingsManager.getDefaultModel();
		const savedModel = savedProvider && savedModelId ? modelRegistry.find(savedProvider, savedModelId) : undefined;
		const savedInScope = savedModel ? scopedModels.find((sm) => modelsAreEqual(sm.model, savedModel)) : undefined;

		if (savedInScope) {
			options.model = savedInScope.model;
			// Use thinking level from scoped model config if explicitly set
			if (!parsed.thinking && savedInScope.thinkingLevel) {
				options.thinkingLevel = savedInScope.thinkingLevel;
			}
		} else {
			options.model = scopedModels[0].model;
			// Use thinking level from first scoped model if explicitly set
			if (!parsed.thinking && scopedModels[0].thinkingLevel) {
				options.thinkingLevel = scopedModels[0].thinkingLevel;
			}
		}
	}

	// Thinking level from CLI (takes precedence over scoped model thinking levels set above)
	if (parsed.thinking) {
		options.thinkingLevel = parsed.thinking;
	}

	// Scoped models for Ctrl+P cycling
	// Keep thinking level undefined when not explicitly set in the model pattern.
	// Undefined means "inherit current session thinking level" during cycling.
	if (scopedModels.length > 0) {
		options.scopedModels = scopedModels.map((sm) => ({
			model: sm.model,
			thinkingLevel: sm.thinkingLevel,
		}));
	}

	// API key from CLI - set in authStorage
	// (handled by caller before createAgentSession)

	// Tools
	if (parsed.noTools) {
		options.noTools = "all";
	} else if (parsed.noBuiltinTools) {
		options.noTools = "builtin";
	}
	if (parsed.tools) {
		options.tools = [...parsed.tools];
	}
	if (parsed.excludeTools) {
		options.excludeTools = [...parsed.excludeTools];
	}

	return { options, cliThinkingFromModel, diagnostics };
}

function resolveCliPaths(cwd: string, paths: string[] | undefined): string[] | undefined {
	return paths?.map((value) => (isLocalPath(value) ? resolvePath(value, cwd) : value));
}

function createStartupTui(settingsManager: SettingsManager): TUI {
	initTheme(settingsManager.getTheme());
	setKeybindings(KeybindingsManager.create());
	const ui = new TUI(new ProcessTerminal(), settingsManager.getShowHardwareCursor());
	ui.setClearOnShrink(settingsManager.getClearOnShrink());
	return ui;
}

async function clearStartupTui(ui: TUI): Promise<void> {
	ui.clear();
	ui.requestRender();
	await new Promise((resolve) => setTimeout(resolve, 25));
}

async function showStartupSelector<T>(
	settingsManager: SettingsManager,
	title: string,
	options: Array<{ label: string; value: T }>,
): Promise<T | undefined> {
	return new Promise((resolve) => {
		const ui = createStartupTui(settingsManager);

		let settled = false;
		const finish = async (result: T | undefined) => {
			if (settled) {
				return;
			}
			settled = true;
			await clearStartupTui(ui);
			ui.stop();
			resolve(result);
		};

		const selector = new ExtensionSelectorComponent(
			title,
			options.map((option) => option.label),
			(option) => void finish(options.find((entry) => entry.label === option)?.value),
			() => void finish(undefined),
			{ tui: ui },
		);
		ui.addChild(selector);
		ui.setFocus(selector);
		ui.start();
	});
}

async function showStartupInput(
	settingsManager: SettingsManager,
	title: string,
	placeholder?: string,
): Promise<string | undefined> {
	return new Promise((resolve) => {
		const ui = createStartupTui(settingsManager);

		let settled = false;
		const finish = async (result: string | undefined) => {
			if (settled) {
				return;
			}
			settled = true;
			input.dispose();
			await clearStartupTui(ui);
			ui.stop();
			resolve(result);
		};

		const input = new ExtensionInputComponent(
			title,
			placeholder,
			(value) => void finish(value),
			() => void finish(undefined),
			{
				tui: ui,
			},
		);
		ui.addChild(input);
		ui.setFocus(input);
		ui.start();
	});
}

async function promptForMissingSessionCwd(
	issue: SessionCwdIssue,
	settingsManager: SettingsManager,
): Promise<string | undefined> {
	return showStartupSelector(settingsManager, formatMissingSessionCwdPrompt(issue), [
		{ label: "Continue", value: issue.fallbackCwd },
		{ label: "Cancel", value: undefined },
	]);
}

interface ProjectTrustPromptResult {
	trusted: boolean;
	remember: boolean;
}

const PROJECT_TRUST_PROMPT_OPTIONS: Array<{ label: string; value: ProjectTrustPromptResult }> = [
	{ label: "Trust", value: { trusted: true, remember: true } },
	{ label: "Trust (this session only)", value: { trusted: true, remember: false } },
	{ label: "Do not trust", value: { trusted: false, remember: true } },
	{ label: "Do not trust (this session only)", value: { trusted: false, remember: false } },
];

function formatProjectTrustPrompt(cwd: string): string {
	return `Trust project folder?\n${cwd}\n\nThis allows pi to read project instructions (AGENTS.md/CLAUDE.md), load .pi settings and resources, install missing project packages, and execute project extensions.`;
}

async function promptForProjectTrust(
	cwd: string,
	settingsManager: SettingsManager,
): Promise<ProjectTrustPromptResult | undefined> {
	return showStartupSelector(settingsManager, formatProjectTrustPrompt(cwd), PROJECT_TRUST_PROMPT_OPTIONS);
}

async function promptForProjectTrustWithContext(
	cwd: string,
	ctx: ProjectTrustContext,
): Promise<ProjectTrustPromptResult | undefined> {
	const selected = await ctx.ui.select(
		formatProjectTrustPrompt(cwd),
		PROJECT_TRUST_PROMPT_OPTIONS.map((option) => option.label),
	);
	return PROJECT_TRUST_PROMPT_OPTIONS.find((option) => option.label === selected)?.value;
}

function createProjectTrustContext(options: {
	cwd: string;
	mode: AppMode;
	settingsManager: SettingsManager;
	hasUI: boolean;
}): ProjectTrustContext {
	return {
		cwd: options.cwd,
		mode: options.mode === "interactive" ? "tui" : options.mode,
		hasUI: options.hasUI,
		ui: {
			select: async (title, selectOptions) => {
				if (!options.hasUI) {
					return undefined;
				}
				if (options.mode !== "interactive") {
					return undefined;
				}
				return showStartupSelector(
					options.settingsManager,
					title,
					selectOptions.map((option) => ({ label: option, value: option })),
				);
			},
			confirm: async (title, message) => {
				if (!options.hasUI) {
					return false;
				}
				if (options.mode !== "interactive") {
					return false;
				}
				return (
					(await showStartupSelector(options.settingsManager, `${title}\n${message}`, [
						{ label: "Yes", value: true },
						{ label: "No", value: false },
					])) ?? false
				);
			},
			input: async (title, placeholder) => {
				if (!options.hasUI) {
					return undefined;
				}
				if (options.mode !== "interactive") {
					return undefined;
				}
				return showStartupInput(options.settingsManager, title, placeholder);
			},
			notify: (message, type = "info") => {
				if (options.mode !== "interactive") {
					const color = type === "error" ? chalk.red : type === "warning" ? chalk.yellow : chalk.cyan;
					console.error(color(message));
				}
			},
		},
	};
}

async function resolveProjectTrusted(options: {
	cwd: string;
	trustStore: ProjectTrustStore;
	trustOverride?: boolean;
	appMode: AppMode;
	settingsManagerForPrompt: SettingsManager;
	extensionsResult?: LoadExtensionsResult;
	projectTrustContext?: ProjectTrustContext;
	onExtensionError?: (message: string) => void;
}): Promise<boolean> {
	if (options.trustOverride !== undefined) {
		return options.trustOverride;
	}
	if (!hasProjectTrustInputs(options.cwd)) {
		return true;
	}

	if (options.extensionsResult && options.projectTrustContext) {
		const { result, errors } = await emitProjectTrustEvent(
			options.extensionsResult,
			{ type: "project_trust", cwd: options.cwd },
			options.projectTrustContext,
		);
		for (const error of errors) {
			options.onExtensionError?.(`Extension "${error.extensionPath}" project_trust error: ${error.error}`);
		}
		if (result) {
			const trusted = result.trusted === "yes";
			if (result.remember === true) {
				options.trustStore.set(options.cwd, trusted);
			}
			return trusted;
		}
	}

	const decision = options.trustStore.get(options.cwd);
	if (decision !== null) {
		return decision;
	}
	if (options.projectTrustContext?.hasUI) {
		const selected = await promptForProjectTrustWithContext(options.cwd, options.projectTrustContext);
		if (selected !== undefined) {
			if (selected.remember) {
				options.trustStore.set(options.cwd, selected.trusted);
			}
			return selected.trusted;
		}
		return false;
	}
	if (options.appMode !== "interactive") {
		return false;
	}

	const selected = await promptForProjectTrust(options.cwd, options.settingsManagerForPrompt);
	if (selected !== undefined) {
		if (selected.remember) {
			options.trustStore.set(options.cwd, selected.trusted);
		}
		return selected.trusted;
	}
	return false;
}

export interface MainOptions {
	extensionFactories?: ExtensionFactory[];
}

export async function main(args: string[], options?: MainOptions) {
	resetTimings();
	const offlineMode = args.includes("--offline") || isTruthyEnvFlag(process.env.PI_OFFLINE);
	if (offlineMode) {
		process.env.PI_OFFLINE = "1";
		process.env.PI_SKIP_VERSION_CHECK = "1";
	}

	if (process.platform === "win32") {
		cleanupWindowsSelfUpdateQuarantine(getPackageDir());
	}

	if (await handlePackageCommand(args)) {
		return;
	}

	if (await handleConfigCommand(args)) {
		return;
	}

	const parsed = parseArgs(args);
	if (parsed.diagnostics.length > 0) {
		for (const d of parsed.diagnostics) {
			const color = d.type === "error" ? chalk.red : chalk.yellow;
			console.error(color(`${d.type === "error" ? "Error" : "Warning"}: ${d.message}`));
		}
		if (parsed.diagnostics.some((d) => d.type === "error")) {
			process.exit(1);
		}
	}
	time("parseArgs");
	let appMode = resolveAppMode(parsed, process.stdin.isTTY);
	const shouldTakeOverStdout = appMode !== "interactive";
	if (shouldTakeOverStdout) {
		takeOverStdout();
	}

	if (parsed.version) {
		console.log(VERSION);
		process.exit(0);
	}

	if (parsed.export) {
		let result: string;
		try {
			const outputPath = parsed.messages.length > 0 ? parsed.messages[0] : undefined;
			result = await exportFromFile(parsed.export, outputPath);
		} catch (error: unknown) {
			const message = error instanceof Error ? error.message : "Failed to export session";
			console.error(chalk.red(`Error: ${message}`));
			process.exit(1);
		}
		console.log(`Exported to: ${result}`);
		process.exit(0);
	}

	if (parsed.mode === "rpc" && parsed.fileArgs.length > 0) {
		console.error(chalk.red("Error: @file arguments are not supported in RPC mode"));
		process.exit(1);
	}

	validateForkFlags(parsed);
	validateSessionIdFlags(parsed);

	// Run migrations (pass cwd for project-local migrations)
	const { migratedAuthProviders: migratedProviders, deprecationWarnings } = runMigrations(process.cwd());
	time("runMigrations");

	const cwd = process.cwd();
	const agentDir = getAgentDir();
	const startupSettingsManager = SettingsManager.create(cwd, agentDir);
	reportDiagnostics(collectSettingsDiagnostics(startupSettingsManager, "startup session lookup"));

	// Decide the final runtime cwd before creating cwd-bound runtime services.
	// --session and --resume may select a session from another project, so project-local
	// settings, resources, provider registrations, and models must be resolved only after
	// the target session cwd is known. The startup-cwd settings manager is used only for
	// sessionDir lookup during session selection.
	const envSessionDir = process.env[ENV_SESSION_DIR];
	const sessionDir =
		(parsed.sessionDir ? normalizePath(parsed.sessionDir) : undefined) ??
		(envSessionDir ? expandTildePath(envSessionDir) : undefined) ??
		startupSettingsManager.getSessionDir();
	let sessionManager = await createSessionManager(parsed, cwd, sessionDir, startupSettingsManager);
	const missingSessionCwdIssue = getMissingSessionCwdIssue(sessionManager, cwd);
	if (missingSessionCwdIssue) {
		if (appMode === "interactive") {
			const selectedCwd = await promptForMissingSessionCwd(missingSessionCwdIssue, startupSettingsManager);
			if (!selectedCwd) {
				process.exit(0);
			}
			sessionManager = SessionManager.open(missingSessionCwdIssue.sessionFile!, sessionDir, selectedCwd);
		} else {
			console.error(chalk.red(new MissingSessionCwdError(missingSessionCwdIssue).message));
			process.exit(1);
		}
	}
	if (parsed.name !== undefined) {
		const name = parsed.name.trim();
		if (!name) {
			console.error(chalk.red("Error: --name requires a non-empty value"));
			process.exit(1);
		}
		sessionManager.appendSessionInfo(name);
	}
	time("createSessionManager");

	const trustStore = new ProjectTrustStore(agentDir);
	const sessionCwd = sessionManager.getCwd();
	const autoTrustOnReloadCwd =
		parsed.projectTrustOverride === undefined && !hasProjectTrustInputs(sessionCwd) ? sessionCwd : undefined;
	const trustPromptMode: AppMode = parsed.help || parsed.listModels !== undefined ? "print" : appMode;
	const projectTrustByCwd = new Map<string, boolean>();

	const resolvedExtensionPaths = resolveCliPaths(cwd, parsed.extensions);
	const resolvedSkillPaths = resolveCliPaths(cwd, parsed.skills);
	const resolvedPromptTemplatePaths = resolveCliPaths(cwd, parsed.promptTemplates);
	const resolvedThemePaths = resolveCliPaths(cwd, parsed.themes);
	const authStorage = AuthStorage.create();
	const createRuntime: CreateAgentSessionRuntimeFactory = async ({
		cwd,
		agentDir,
		sessionManager,
		sessionStartEvent,
		projectTrustContext,
	}) => {
		const isInitialRuntime = sessionStartEvent === undefined;
		const projectTrustDiagnostics: AgentSessionRuntimeDiagnostic[] = [];
		const cachedProjectTrust = projectTrustByCwd.get(cwd);
		const hasTrustInputs = hasProjectTrustInputs(cwd);
		const shouldResolveProjectTrust =
			parsed.projectTrustOverride === undefined && cachedProjectTrust === undefined && hasTrustInputs;
		const projectTrusted = shouldResolveProjectTrust
			? false
			: (cachedProjectTrust ?? parsed.projectTrustOverride ?? (!hasTrustInputs || trustStore.get(cwd) === true));
		const runtimeSettingsManager = SettingsManager.create(cwd, agentDir, { projectTrusted });
		const services = await createAgentSessionServices({
			cwd,
			agentDir,
			authStorage,
			settingsManager: runtimeSettingsManager,
			extensionFlagValues: parsed.unknownFlags,
			resourceLoaderReloadOptions: shouldResolveProjectTrust
				? {
						resolveProjectTrust: async ({ extensionsResult }) => {
							const trusted = await resolveProjectTrusted({
								cwd,
								trustStore,
								trustOverride: parsed.projectTrustOverride,
								appMode: isInitialRuntime ? trustPromptMode : "print",
								settingsManagerForPrompt: startupSettingsManager,
								extensionsResult,
								projectTrustContext:
									projectTrustContext ??
									createProjectTrustContext({
										cwd,
										mode: isInitialRuntime ? trustPromptMode : appMode,
										settingsManager: startupSettingsManager,
										hasUI: isInitialRuntime && trustPromptMode === "interactive",
									}),
								onExtensionError: (message) => projectTrustDiagnostics.push({ type: "warning", message }),
							});
							projectTrustByCwd.set(cwd, trusted);
							return trusted;
						},
					}
				: undefined,
			resourceLoaderOptions: {
				additionalExtensionPaths: resolvedExtensionPaths,
				additionalSkillPaths: resolvedSkillPaths,
				additionalPromptTemplatePaths: resolvedPromptTemplatePaths,
				additionalThemePaths: resolvedThemePaths,
				noExtensions: parsed.noExtensions,
				noSkills: parsed.noSkills,
				noPromptTemplates: parsed.noPromptTemplates,
				noThemes: parsed.noThemes,
				noContextFiles: parsed.noContextFiles,
				systemPrompt: parsed.systemPrompt,
				appendSystemPrompt: parsed.appendSystemPrompt,
				extensionFactories: options?.extensionFactories,
			},
		});
		const { settingsManager, modelRegistry, resourceLoader } = services;
		const diagnostics: AgentSessionRuntimeDiagnostic[] = [
			...projectTrustDiagnostics,
			...services.diagnostics,
			...collectSettingsDiagnostics(settingsManager, "runtime creation"),
			...resourceLoader.getExtensions().errors.map(({ path, error }) => ({
				type: "error" as const,
				message: `Failed to load extension "${path}": ${error}`,
			})),
		];

		const modelPatterns = parsed.models ?? settingsManager.getEnabledModels();
		const scopedModels =
			modelPatterns && modelPatterns.length > 0 ? await resolveModelScope(modelPatterns, modelRegistry) : [];
		const {
			options: sessionOptions,
			cliThinkingFromModel,
			diagnostics: sessionOptionDiagnostics,
		} = buildSessionOptions(
			parsed,
			scopedModels,
			sessionManager.buildSessionContext().messages.length > 0,
			modelRegistry,
			settingsManager,
		);
		diagnostics.push(...sessionOptionDiagnostics);

		if (parsed.apiKey) {
			if (!sessionOptions.model) {
				diagnostics.push({
					type: "error",
					message: "--api-key requires a model to be specified via --model, --provider/--model, or --models",
				});
			} else {
				authStorage.setRuntimeApiKey(sessionOptions.model.provider, parsed.apiKey);
			}
		}

		const created = await createAgentSessionFromServices({
			services,
			sessionManager,
			sessionStartEvent,
			model: sessionOptions.model,
			thinkingLevel: sessionOptions.thinkingLevel,
			scopedModels: sessionOptions.scopedModels,
			tools: sessionOptions.tools,
			excludeTools: sessionOptions.excludeTools,
			noTools: sessionOptions.noTools,
			customTools: sessionOptions.customTools,
		});
		const cliThinkingOverride = parsed.thinking !== undefined || cliThinkingFromModel;
		if (created.session.model && cliThinkingOverride) {
			created.session.setThinkingLevel(created.session.thinkingLevel);
		}

		return {
			...created,
			services,
			diagnostics,
		};
	};
	time("createRuntime");
	const runtime = await createAgentSessionRuntime(createRuntime, {
		cwd: sessionManager.getCwd(),
		agentDir,
		sessionManager,
	});
	time("createAgentSessionRuntime");
	const { services, session, modelFallbackMessage } = runtime;
	const { settingsManager, modelRegistry, resourceLoader } = services;
	configureHttpDispatcher(settingsManager.getHttpIdleTimeoutMs());

	if (parsed.help) {
		const extensionFlags = resourceLoader
			.getExtensions()
			.extensions.flatMap((extension) => Array.from(extension.flags.values()));
		printHelp(extensionFlags);
		process.exit(0);
	}

	if (parsed.listModels !== undefined) {
		const searchPattern = typeof parsed.listModels === "string" ? parsed.listModels : undefined;
		await listModels(modelRegistry, searchPattern);
		process.exit(0);
	}

	// Read piped stdin content (if any) - skip for RPC mode which uses stdin for JSON-RPC
	let stdinContent: string | undefined;
	if (appMode !== "rpc") {
		stdinContent = await readPipedStdin();
		if (stdinContent !== undefined && appMode === "interactive") {
			appMode = "print";
		}
	}
	time("readPipedStdin");

	const { initialMessage, initialImages } = await prepareInitialMessage(
		parsed,
		settingsManager.getImageAutoResize(),
		stdinContent,
	);
	time("prepareInitialMessage");
	initTheme(settingsManager.getTheme(), appMode === "interactive");
	time("initTheme");

	// Show deprecation warnings in interactive mode
	if (appMode === "interactive" && deprecationWarnings.length > 0) {
		await showDeprecationWarnings(deprecationWarnings);
	}

	time("resolveModelScope");
	reportDiagnostics(runtime.diagnostics);
	if (runtime.diagnostics.some((diagnostic) => diagnostic.type === "error")) {
		process.exit(1);
	}
	time("createAgentSession");

	if (appMode !== "interactive" && !session.model) {
		console.error(chalk.red(formatNoModelsAvailableMessage()));
		process.exit(1);
	}

	const startupBenchmark = isTruthyEnvFlag(process.env.PI_STARTUP_BENCHMARK);
	if (startupBenchmark && appMode !== "interactive") {
		console.error(chalk.red("Error: PI_STARTUP_BENCHMARK only supports interactive mode"));
		process.exit(1);
	}

	if (appMode === "rpc") {
		printTimings();
		await runRpcMode(runtime);
	} else if (appMode === "interactive") {
		const interactiveMode = new InteractiveMode(runtime, {
			migratedProviders,
			modelFallbackMessage,
			autoTrustOnReloadCwd,
			initialMessage,
			initialImages,
			initialMessages: parsed.messages,
			verbose: parsed.verbose,
		});
		if (startupBenchmark) {
			await interactiveMode.init();
			time("interactiveMode.init");
			printTimings();
			interactiveMode.stop();
			stopThemeWatcher();
			if (process.stdout.writableLength > 0) {
				await new Promise<void>((resolve) => process.stdout.once("drain", resolve));
			}
			if (process.stderr.writableLength > 0) {
				await new Promise<void>((resolve) => process.stderr.once("drain", resolve));
			}
			return;
		}

		printTimings();
		await interactiveMode.run();
	} else {
		printTimings();
		const exitCode = await runPrintMode(runtime, {
			mode: toPrintOutputMode(appMode),
			messages: parsed.messages,
			initialMessage,
			initialImages,
		});
		stopThemeWatcher();
		restoreStdout();
		if (exitCode !== 0) {
			process.exitCode = exitCode;
		}
		return;
	}
}