#!/usr/bin/env node

// ./script/cargo is a transparent wrapper around cargo that:
// - When running in a clone of `./zed-industries/zed`
// - outputs build timings to the ZED_DATA_DIR/build_timings
// When Zed starts for staff-members it uploads the build timings to Snowflake
// To use it:
//  ./script/cargo --init
// This will add a wrapper to your shell configuration files.
// (Otherwise set up an alias `cargo=PATH_TO_THIS_FILE`)

// We need to ignore SIGINT in this process so that we can continue
// processing timing files after the child cargo process exits.
// The signal will still be delivered to the child process.
process.on("SIGINT", () => {});

const { spawn, spawnSync } = require("child_process");
const fs = require("fs");
const os = require("os");
const path = require("path");
const readline = require("readline");

const SUBCOMMANDS_WITH_TIMINGS = new Set(["build", "check", "run", "test"]);

// Built-in cargo aliases
const CARGO_ALIASES = {
  b: "build",
  c: "check",
  t: "test",
  r: "run",
  d: "doc",
};

function expandAlias(subcommand) {
  return CARGO_ALIASES[subcommand] || subcommand;
}

function detectShell() {
  // Check for PowerShell first (works when running from pwsh)
  if (process.env.PSModulePath && !process.env.BASH_VERSION) {
    return "powershell";
  }

  const shell = process.env.SHELL || "";
  if (shell.endsWith("/zsh")) return "zsh";
  if (shell.endsWith("/bash")) return "bash";
  if (shell.endsWith("/fish")) return "fish";
  if (shell.endsWith("/pwsh") || shell.endsWith("/powershell")) return "powershell";
  return path.basename(shell) || "unknown";
}

function getShellConfigPath(shell) {
  const home = os.homedir();
  switch (shell) {
    case "zsh":
      return path.join(process.env.ZDOTDIR || home, ".zshrc");
    case "bash":
      // Prefer .bashrc, fall back to .bash_profile
      const bashrc = path.join(home, ".bashrc");
      if (fs.existsSync(bashrc)) return bashrc;
      return path.join(home, ".bash_profile");
    case "fish":
      return path.join(home, ".config", "fish", "config.fish");
    case "powershell":
      if (process.platform === "win32") {
        // Spawn PowerShell to get the real $PROFILE path, since os.homedir() doesn't account
        // for OneDrive folder redirection, and the subdirectory differs between Windows PowerShell
        // 5.x ("WindowsPowerShell") and PowerShell Core ("PowerShell").
        const psModulePath = process.env.PSModulePath || "";
        const psExe = psModulePath.toLowerCase().includes("\\windowspowershell\\") ? "powershell" : "pwsh";
        const result = spawnSync(psExe, ["-NoProfile", "-Command", "$PROFILE"], {
          encoding: "utf-8",
          stdio: ["pipe", "pipe", "pipe"],
          timeout: 5000,
        });
        if (result.status === 0 && result.stdout.trim()) {
          return result.stdout.trim();
        }
        // Fallback if spawning fails
        return path.join(home, "Documents", "PowerShell", "Microsoft.PowerShell_profile.ps1");
      } else {
        return path.join(home, ".config", "powershell", "Microsoft.PowerShell_profile.ps1");
      }
    default:
      return null;
  }
}

function generateAlias(shell, scriptDir) {
  const cargoWrapper = path.join(scriptDir, "cargo");

  switch (shell) {
    case "zsh":
    case "bash":
      return `\n# Zed cargo timing wrapper\ncargo() { local w="${cargoWrapper}"; if [[ -x "$w" ]]; then "$w" "$@"; else command cargo "$@"; fi; }\n`;
    case "fish":
      return `\n# Zed cargo timing wrapper\nfunction cargo\n    set -l w "${cargoWrapper}"\n    if test -x "$w"\n        "$w" $argv\n        return $status\n    else\n        command cargo $argv\n    end\nend\n`;
    case "powershell":
      return `\n# Zed cargo timing wrapper\nfunction cargo {\n    \$wrapper = "${cargoWrapper}"\n    if (Test-Path \$wrapper) {\n        node \$wrapper @args\n    } else {\n        & (Get-Command -Name cargo -CommandType Application | Select-Object -First 1).Source @args\n    }\n}\n`;
    default:
      return `cargo() { local w="${cargoWrapper}"; if [[ -x "$w" ]]; then "$w" "$@"; else command cargo "$@"; fi; }`;
  }
}

function aliasBlockRegex(shell) {
  switch (shell) {
    case "zsh":
    case "bash":
      // Comment line + single-line cargo() { ... } function
      return /\n?# Zed cargo timing wrapper\ncargo\(\) \{[^\n]*\}\n/;
    case "fish":
      // Comment line + multi-line function cargo...end block
      return /\n?# Zed cargo timing wrapper\nfunction cargo\n[\s\S]*?\nend\n/;
    case "powershell":
      // Comment line + multi-line function cargo {...} block
      return /\n?# Zed cargo timing wrapper\nfunction cargo \{[\s\S]*?\n\}\n/;
    default:
      return null;
  }
}

function initShellAlias() {
  const scriptDir = __dirname;
  const shell = detectShell();
  const configPath = getShellConfigPath(shell);
  const alias = generateAlias(shell, scriptDir);

  if (!configPath) {
    console.log(`Unsupported shell: ${shell}`);
    console.log("\nAdd the following to your shell configuration:\n");
    console.log(alias);
    return;
  }

  // Check if alias already exists; if so, replace it in-place
  if (fs.existsSync(configPath)) {
    const content = fs.readFileSync(configPath, "utf-8");
    if (content.includes("Zed cargo timing wrapper")) {
      const blockRegex = aliasBlockRegex(shell);
      const updated = blockRegex ? content.replace(blockRegex, "") : content;
      fs.writeFileSync(configPath, updated + alias);
      console.log(`Updated cargo timing alias in ${configPath}`);
      if (shell === "powershell") {
        console.log(`\nRestart PowerShell or run: . "${configPath}"`);
      } else {
        console.log(`\nRestart your shell or run: source ${configPath}`);
      }
      return;
    }
  }

  // Create parent directory if needed (for PowerShell on Linux/macOS)
  const configDir = path.dirname(configPath);
  if (!fs.existsSync(configDir)) {
    fs.mkdirSync(configDir, { recursive: true });
  }

  // Append alias to config file
  fs.appendFileSync(configPath, alias);
  console.log(`Added cargo timing alias to ${configPath}`);

  if (shell === "powershell") {
    console.log(`\nRestart PowerShell or run: . "${configPath}"`);
  } else {
    console.log(`\nRestart your shell or run: source ${configPath}`);
  }
}

function isZedRepo() {
  try {
    const result = spawnSync("git", ["remote", "-v"], {
      encoding: "utf-8",
      stdio: ["pipe", "pipe", "pipe"],
      timeout: 5000,
    });
    if (result.status !== 0 || !result.stdout) {
      return false;
    }
    return result.stdout.includes("zed-industries/zed");
  } catch {
    return false;
  }
}

function findSubcommand(args) {
  for (let i = 0; i < args.length; i++) {
    const arg = args[i];
    // Skip flags and their values
    if (arg.startsWith("-")) {
      // If this flag takes a value and it's not using = syntax, skip the next arg too
      if (!arg.includes("=") && i + 1 < args.length && !args[i + 1].startsWith("-")) {
        i++;
      }
      continue;
    }
    // First non-flag argument is the subcommand
    return { subcommand: arg, index: i };
  }
  return null;
}

function findLatestTimingFile(targetDir) {
  const timingsDir = path.join(targetDir, "cargo-timings");
  if (!fs.existsSync(timingsDir)) {
    return null;
  }

  const files = fs
    .readdirSync(timingsDir)
    .filter((f) => f.startsWith("cargo-timing-") && f.endsWith(".html") && f !== "cargo-timing.html")
    .map((f) => ({
      name: f,
      path: path.join(timingsDir, f),
      mtime: fs.statSync(path.join(timingsDir, f)).mtime.getTime(),
    }))
    .sort((a, b) => b.mtime - a.mtime);

  return files.length > 0 ? files[0].path : null;
}

function getTargetDir(args) {
  // Check for --target-dir flag
  for (let i = 0; i < args.length; i++) {
    if (args[i] === "--target-dir" && i + 1 < args.length) {
      return args[i + 1];
    }
    if (args[i].startsWith("--target-dir=")) {
      return args[i].substring("--target-dir=".length);
    }
  }
  // Default target directory
  return "target";
}

function runCargoPassthrough(args) {
  const cargoCmd = process.env.CARGO || "cargo";
  const result = spawnSync(cargoCmd, args, {
    stdio: "inherit",
    shell: false,
  });
  process.exit(result.status ?? 1);
}

async function main() {
  const args = process.argv.slice(2);

  // Handle --init flag
  if (args[0] === "--init") {
    if (process.env.NIX_WRAPPER === "1") {
      console.error("`--init` not supported when going through the nix wrapper");
      process.exit(1);
    }
    initShellAlias();
    return;
  }

  // If not in zed repo, just pass through to cargo
  if (!isZedRepo()) {
    runCargoPassthrough(args);
    return;
  }

  const cargoCmd = process.env.CARGO || "cargo";
  const subcommandInfo = findSubcommand(args);
  const expandedSubcommand = subcommandInfo ? expandAlias(subcommandInfo.subcommand) : null;
  const shouldAddTimings = expandedSubcommand && SUBCOMMANDS_WITH_TIMINGS.has(expandedSubcommand);

  // Build the final args array
  let finalArgs = [...args];
  if (shouldAddTimings) {
    // Check if --timings is already present
    const hasTimings = args.some((arg) => arg === "--timings" || arg.startsWith("--timings="));
    if (!hasTimings) {
      // Insert --timings after the subcommand
      finalArgs.splice(subcommandInfo.index + 1, 0, "--timings");
    }
  }

  // Run cargo asynchronously so we can handle signals properly
  const child = spawn(cargoCmd, finalArgs, {
    stdio: "inherit",
    shell: false,
  });

  // Wait for the child to exit
  const result = await new Promise((resolve) => {
    child.on("exit", (code, signal) => {
      resolve({ status: code, signal });
    });
  });

  // If we added timings, try to process the timing file (regardless of cargo's exit status)
  if (shouldAddTimings) {
    const targetDir = getTargetDir(args);
    const timingFile = findLatestTimingFile(targetDir);

    if (timingFile) {
      // Run cargo-timing-info.js in the background
      const scriptDir = __dirname;
      const timingScript = path.join(scriptDir, "cargo-timing-info.js");

      if (fs.existsSync(timingScript)) {
        const timingChild = spawn(process.execPath, [timingScript, timingFile, `cargo ${expandedSubcommand}`], {
          detached: true,
          stdio: "ignore",
        });
        timingChild.unref();
      }
    }
  }

  // Exit with cargo's exit code, or re-raise the signal if it was killed
  if (result.signal) {
    // Reset signal handler and re-raise so parent sees the signal
    process.removeAllListeners(result.signal);
    process.kill(process.pid, result.signal);
  } else {
    process.exit(result.status ?? 1);
  }
}

main();