import { $ } from "bun"
import { constants, setPriority } from "node:os"
import { join } from "node:path"
import { fileURLToPath } from "node:url"
import { prepareDevElectron } from "./dev-electron"
import { downloadCliToResources, windowsify } from "./utils"

type ServerSource = { type: "build" } | { type: "download"; version: string }

type DevOptions = { server: ServerSource; electron: string[] }

async function main() {
  process.env.OPENCODE_CHANNEL = "local"
  process.env.OPENCODE_VERSION ??= `2.0.0-local-${Date.now()}`
  process.env.OPENCODE_DISABLE_CHANNEL_DB = "0"
  const options = selectOptions()

  if (options.server.type === "build") process.env.OPENCODE_DESKTOP_SERVER_CHANNEL = "local"
  process.env.OPENCODE_DESKTOP_ISOLATED_SERVER ??= "1"
  await prepareDesktop()
  await prepareServer(options.server)
  await startDesktop(options.electron)
}

async function prepareDesktop() {
  await Promise.all([
    $`bun run install-electron`,
    $`bun ./scripts/copy-icons.ts ${process.env.OPENCODE_CHANNEL ?? "dev"}`,
  ])

  if (process.platform === "darwin") process.env.ELECTRON_EXEC_PATH = await prepareDevElectron()
}

function selectOptions(): DevOptions {
  const args = process.argv.slice(2)
  const build = args.indexOf("--build-server")
  const download = args.indexOf("--download-server")

  if (build >= 0 && download >= 0) {
    throw new Error("--build-server and --download-server cannot be used together")
  }

  if (download >= 0 && !args[download + 1]) throw new Error("--download-server requires a version")
  const consumed = new Set([build, download, download >= 0 ? download + 1 : -1])

  return {
    server: download >= 0 ? { type: "download", version: args[download + 1] } : { type: "build" },
    electron: args.filter((_, index) => !consumed.has(index)),
  }
}

async function prepareServer(source: ServerSource) {
  if (source.type === "download")
    return downloadCliToResources(source.version, windowsify("resources/opencode-cli-dev"))
  buildWebUi()
  process.env.OPENCODE_DESKTOP_CLI_DEV = join(import.meta.dirname, "../../cli")

  if (process.platform !== "win32") return
  process.env.OPENCODE_DESKTOP_WSL_CLI_BUILD = join(import.meta.dirname, "../../cli/script/build.ts")
  process.env.OPENCODE_DESKTOP_WSL_CLI_OUTPUT = join(import.meta.dirname, "../resources/opencode-cli-wsl")
}

// The source CLI serves packages/app/dist only to paired devices, and nothing on the way to the
// desktop window reads it, so it builds alongside startup instead of before it. Idle priority also
// lowers its disk and memory priority on Windows; below-normal still delayed the window by seconds.
function buildWebUi() {
  const started = performance.now()

  const build = Bun.spawn(["bun", "run", "build"], {
    cwd: join(import.meta.dirname, "../../app"),
    env: { ...process.env, VITE_OPENCODE_SERVER_MODE: "origin" },
    stdio: ["ignore", "ignore", "ignore"],
  })

  setPriority(build.pid, constants.priority.PRIORITY_LOW)
  build.unref()
  void build.exited.then((code) =>
    console.log(
      code === 0
        ? `Built the pairing web UI in ${((performance.now() - started) / 1000).toFixed(1)} s`
        : `Pairing web UI build failed with code ${code}; run 'bun run --cwd packages/app build' to see why`,
    ),
  )
}

async function startDesktop(args: string[]) {
  // Bun's implicit spawn environment omits values set during preparation.
  process.exitCode = await Bun.spawn(
    ["node", fileURLToPath(new URL("../bin/electron-vite.js", import.meta.resolve("electron-vite"))), "dev", ...args],
    { env: process.env, stdio: ["inherit", "inherit", "inherit"] },
  ).exited
}

await main()