/**
 * sproutclaw / mengya 命令安装扩展
 *
 * 在 Linux 和 Windows 上分别创建/更新以下命令：
 * - mengya：源码版（Linux: ./pi-test.sh，Windows: pi-test.bat）
 * - sproutclaw：构建版（Linux: ./pi-built.sh，Windows: pi-built.bat）
 *
 * Linux 命令安装到 /usr/local/bin/。
 * Windows 批处理文件创建在项目根目录，需要把项目根目录加入 PATH 后全局使用。
 *
 * 命令 /install-commands 可随时手动重装。
 */

import { existsSync, writeFileSync, chmodSync, readFileSync } from "node:fs";
import { dirname, join } from "node:path";
import { fileURLToPath } from "node:url";
import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";

const extensionDir = typeof __dirname !== "undefined" ? __dirname : dirname(fileURLToPath(import.meta.url));
const SPROUTCLAW_DIR = dirname(dirname(dirname(dirname(extensionDir))));
const LINUX_BIN_DIR = "/usr/local/bin";

// ---------------------------- Linux scripts ----------------------------

function linuxMengyaScript(): string {
	return `#!/usr/bin/env bash
set -euo pipefail
cd "${SPROUTCLAW_DIR}"
exec ./pi-test.sh "$@"
`;
}

function linuxSproutclawScript(): string {
	return `#!/usr/bin/env bash
set -euo pipefail
cd "${SPROUTCLAW_DIR}"

case "\${1:-}" in
\tbuild)
\t\tshift
\t\texec npm run build "$@"
\t\t;;
\trun)
\t\tshift
\t\texec ./pi-built.sh "$@"
\t\t;;
\thelp|-h|--help)
\t\tcat <<'EOF'
sproutclaw - SproutClaw pi 构建版启动器

用法:
  sproutclaw              启动 pi（构建版）
  sproutclaw run [args]   同 sproutclaw
  sproutclaw build        从源码构建所有包

其余参数透传给 pi，例如: sproutclaw --version
EOF
\t\t;;
\t*)
\t\texec ./pi-built.sh "$@"
\t\t;;
esac
`;
}

// ---------------------------- Windows scripts ----------------------------

function windowsMengyaBat(): string {
	return `@echo off
setlocal
set "SCRIPT_DIR=%~dp0"
if "%SCRIPT_DIR:~-1%"=="\" set "SCRIPT_DIR=%SCRIPT_DIR:~0,-1%"
if not defined PI_CODING_AGENT_DIR (
    set "PI_CODING_AGENT_DIR=%SCRIPT_DIR%\.pi\agent"
)
call "%SCRIPT_DIR%\pi-test.bat" %*
exit /b %ERRORLEVEL%
`;
}

function windowsSproutclawBat(): string {
	return `@echo off
setlocal
set "SCRIPT_DIR=%~dp0"
if "%SCRIPT_DIR:~-1%"=="\" set "SCRIPT_DIR=%SCRIPT_DIR:~0,-1%"
if not defined PI_CODING_AGENT_DIR (
    set "PI_CODING_AGENT_DIR=%SCRIPT_DIR%\.pi\agent"
)

if "%~1"=="" goto run
if /I "%~1"=="run" (
    shift
    goto run
)
if /I "%~1"=="build" (
    shift
    npm run build %*
    exit /b %ERRORLEVEL%
)
if /I "%~1"=="help" goto help
if "%~1"=="-h" goto help
if "%~1"=="--help" goto help

:run
call "%SCRIPT_DIR%\pi-built.bat" %*
exit /b %ERRORLEVEL%

:help
echo sproutclaw - SproutClaw pi 构建版启动器
echo.
echo 用法:
echo   sproutclaw              启动 pi（构建版）
echo   sproutclaw run [args]   同 sproutclaw
echo   sproutclaw build        从源码构建所有包
echo.
echo 其余参数透传给 pi，例如: sproutclaw --version
exit /b 0
`;
}

// ---------------------------- Install helpers ----------------------------

function writeIfChanged(path: string, content: string, mode?: number): boolean {
	if (existsSync(path)) {
		try {
			const current = readFileSync(path, "utf-8");
			if (current === content) return false;
		} catch {
			// Rewrite unreadable or invalid files below.
		}
	}
	writeFileSync(path, content, "utf-8");
	if (mode !== undefined) chmodSync(path, mode);
	return true;
}

function installLinuxCommands(): string[] {
	const created: string[] = [];
	if (writeIfChanged(join(LINUX_BIN_DIR, "mengya"), linuxMengyaScript(), 0o755)) {
		created.push("/usr/local/bin/mengya");
	}
	if (writeIfChanged(join(LINUX_BIN_DIR, "sproutclaw"), linuxSproutclawScript(), 0o755)) {
		created.push("/usr/local/bin/sproutclaw");
	}
	return created;
}

function installWindowsCommands(): string[] {
	const created: string[] = [];
	if (writeIfChanged(join(SPROUTCLAW_DIR, "mengya.bat"), windowsMengyaBat())) {
		created.push(join(SPROUTCLAW_DIR, "mengya.bat"));
	}
	if (writeIfChanged(join(SPROUTCLAW_DIR, "sproutclaw.bat"), windowsSproutclawBat())) {
		created.push(join(SPROUTCLAW_DIR, "sproutclaw.bat"));
	}
	return created;
}

// ---------------------------- Extension entry ----------------------------

export default function (pi: ExtensionAPI) {
	const isWindows = process.platform === "win32";

	function install(): string[] {
		return isWindows ? installWindowsCommands() : installLinuxCommands();
	}

	const created = install();
	for (const path of created) {
		console.log(`[sproutclaw-setup] Created/updated ${path}`);
	}

	pi.registerCommand("install-commands", {
		description: isWindows
			? "Install mengya.bat (source) and sproutclaw.bat (built) to the repo root"
			: "Install mengya (source) and sproutclaw (built) to /usr/local/bin",
		handler: async (_args, ctx) => {
			const paths = install();
			if (paths.length > 0) {
				ctx.ui.notify(`Installed/updated ${paths.length} command(s):\n${paths.join("\n")}`, "success");
			} else {
				ctx.ui.notify("Commands already up to date", "info");
			}
			if (isWindows) {
				ctx.ui.notify(`请把项目目录加入 PATH 以全局使用：\n${SPROUTCLAW_DIR}`, "info");
			}
		},
	});
}