import { $ } from "bun"
import { homedir } from "os"
import { dirname } from "path"

const CONTAINER_NAME = "sandlot"
const USER = "ubuntu"
const CLAUDE_BIN = `/home/${USER}/.local/bin/claude`

/** Translate a host path to its corresponding container path. */
export function containerPath(hostPath: string): string {
  const home = homedir()
  if (hostPath.startsWith(`${home}/.sandlot`)) {
    return "/sandlot" + hostPath.slice(`${home}/.sandlot`.length)
  }
  if (hostPath.startsWith(`${home}/dev`)) {
    return "/host" + hostPath.slice(`${home}/dev`.length)
  }
  return hostPath
}

function requireContainer(): void {
  if (!Bun.which("container")) {
    console.error('✖ Apple Container is not installed. Install it with: brew install container')
    process.exit(1)
  }
}

/** Run a shell command, logging stderr on failure. */
async function run(cmd: ReturnType<typeof $>, step: string): Promise<void> {
  const result = await cmd.nothrow().quiet()
  if (result.exitCode !== 0) {
    const stderr = result.stderr.toString().trim()
    const stdout = result.stdout.toString().trim()
    const detail = stderr || stdout || "(no output)"
    throw new Error(`${step} failed (exit ${result.exitCode}):\n${detail}`)
  }
}

/** Create and provision the container from scratch. Fails if it already exists. */
export async function create(log?: (msg: string) => void): Promise<void> {
  requireContainer()

  const s = await status()
  if (s !== "missing") {
    throw new Error("Container already exists. Use 'sandlot vm destroy' first to recreate it.")
  }

  const home = homedir()
  log?.("Pulling image & creating container")
  await run(
    $`container run -d --name ${CONTAINER_NAME} -m 4G --mount type=bind,source=${home}/dev,target=/host,readonly -v ${home}/.sandlot:/sandlot ubuntu:24.04 sleep infinity`,
    "Container creation")

  // Provision (as root)
  log?.("Installing packages")
  await run(
    $`container exec ${CONTAINER_NAME} bash -c ${"apt update && apt install -y curl git neofetch fish unzip"}`,
    "Package installation")

  // Create symlinks so git worktree absolute paths from the host resolve inside the container
  await run(
    $`container exec ${CONTAINER_NAME} bash -c ${`mkdir -p '${home}' && ln -s /host '${home}/dev' && ln -s /sandlot '${home}/.sandlot'`}`,
    "Symlink creation")

  // Install Bun and Claude Code (as ubuntu user)
  log?.("Installing Bun")
  await run(
    $`container exec --user ${USER} ${CONTAINER_NAME} env BUN_INSTALL=/home/${USER}/.local bash -c ${"curl -fsSL https://bun.sh/install | bash"}`,
    "Bun installation")

  log?.("Installing Claude Code")
  await run(
    $`container exec --user ${USER} ${CONTAINER_NAME} bash -c ${"curl -fsSL https://claude.ai/install.sh | bash"}`,
    "Claude Code installation")

  log?.("Configuring environment")
  const gitName = (await $`git config user.name`.quiet().text()).trim()
  const gitEmail = (await $`git config user.email`.quiet().text()).trim()
  if (gitName) await $`container exec --user ${USER} ${CONTAINER_NAME} git config --global user.name ${gitName}`.quiet()
  if (gitEmail) await $`container exec --user ${USER} ${CONTAINER_NAME} git config --global user.email ${gitEmail}`.quiet()

  // Configure claude to use API key from host ~/.env (skip login prompt)
  let apiKey: string | undefined
  const envFile = Bun.file(`${home}/.env`)
  if (await envFile.exists()) {
    const envContent = await envFile.text()
    apiKey = envContent.match(/^(?:export\s+)?ANTHROPIC_API_KEY=["']?([^"'\s]+)["']?/m)?.[1]
  }

  if (!apiKey) {
    log?.("Warning: ANTHROPIC_API_KEY not found in ~/.env — claude will require manual login")
  }

  const activityBin = `/home/${USER}/.local/bin/sandlot-activity`
  const hooks = {
    UserPromptSubmit: [{ hooks: [{ type: "command", command: `${activityBin} active` }] }],
    Stop: [{ hooks: [{ type: "command", command: `${activityBin} idle` }] }],
  }
  const settingsJson = JSON.stringify(apiKey
    ? { apiKeyHelper: "~/.claude/api-key-helper.sh", skipDangerousModePermissionPrompt: true, hooks }
    : { skipDangerousModePermissionPrompt: true, hooks })
  const claudeJson = JSON.stringify({ hasCompletedOnboarding: true, effortCalloutDismissed: true })

  // Write the helper script to a temp file and copy it in so the key
  // never appears in a process argument visible in `ps`.
  if (apiKey) {
    const tmp = `${home}/.sandlot/.api-key-helper.tmp`
    await Bun.write(tmp, `#!/bin/sh\necho '${apiKey.replace(/'/g, "'\\''")}'\n`)
    await $`chmod +x ${tmp}`.quiet()
    await $`container exec --user ${USER} ${CONTAINER_NAME} bash -c ${"mkdir -p ~/.claude && cp /sandlot/.api-key-helper.tmp ~/.claude/api-key-helper.sh"}`.quiet()
    await Bun.file(tmp).unlink()
  }

  // Install activity tracking hook script
  const activityTmp = `${home}/.sandlot/.sandlot-activity.tmp`
  await Bun.write(activityTmp, [
    '#!/bin/bash',
    'P="${CLAUDE_PROJECT_DIR%/}"',
    'echo "$1" > "$(dirname "$P")/.activity-$(basename "$P")"',
    '',
  ].join('\n'))
  await $`chmod +x ${activityTmp}`.quiet()
  await $`container exec --user ${USER} ${CONTAINER_NAME} bash -c ${"cp /sandlot/.sandlot-activity.tmp ~/.local/bin/sandlot-activity"}`.quiet()
  await Bun.file(activityTmp).unlink()

  await $`container exec --user ${USER} ${CONTAINER_NAME} bash -c ${`
mkdir -p ~/.claude
echo '${settingsJson}' > ~/.claude/settings.json
echo '${claudeJson}' > ~/.claude.json
`}`.quiet()
}

/** Start a stopped container. */
export async function start(): Promise<void> {
  requireContainer()
  const s = await status()
  if (s === "running") return
  if (s === "missing") throw new Error("Container does not exist. Use 'sandlot vm create' first.")
  await $`container start ${CONTAINER_NAME}`.quiet()
}

/** Ensure the sandlot container exists and is running. Creates and provisions on first use. */
export async function ensure(log?: (msg: string) => void): Promise<void> {
  requireContainer()

  // Ensure the container daemon is running
  await $`container system start`.nothrow().quiet()

  const s = await status()
  if (s === "running") return

  if (s === "stopped") {
    await start()
    return
  }

  await create(log)
}

/** Check container status. */
export async function status(): Promise<"running" | "stopped" | "missing"> {
  const result = await $`container list --format json --all`.nothrow().quiet().text()

  try {
    const containers = JSON.parse(result.trim())
    const container = containers.find((c: any) => c.configuration?.id === CONTAINER_NAME)
    if (!container) return "missing"
    return container.status?.toLowerCase() === "running" ? "running" : "stopped"
  } catch {
    return "missing"
  }
}

/** Launch claude in the container at the given workdir. */
export async function claude(workdir: string, opts?: { prompt?: string; print?: string }): Promise<string | void> {
  const cwd = containerPath(workdir)
  const systemPromptLines = [
    "You are running inside a sandlot container (Apple Container, ubuntu:24.04).",
    `Your working directory is ${cwd}, a git worktree managed by sandlot.`,
    "The host's ~/dev is mounted read-only at /host.",
    "The host's ~/.sandlot is mounted at /sandlot.",
    "Bun is installed at ~/.local/bin/bun. Use bun instead of node/npm.",
  ]
  if (opts?.print) {
    systemPromptLines.push("IMPORTANT: Do not use plan mode. Do not call the EnterPlanMode tool. Proceed directly with the task.")
  }
  const systemPrompt = systemPromptLines.join("\n")

  const term = process.env.TERM || "xterm-256color"
  const args = ["container", "exec", "-it", "--user", USER, "--workdir", cwd, CONTAINER_NAME, "env", `TERM=${term}`, CLAUDE_BIN, "--dangerously-skip-permissions", "--model", "claude-opus-4-6", "--append-system-prompt", systemPrompt]
  if (opts?.print) args.push("-p", opts.print)
  else if (opts?.prompt) args.push(opts.prompt)

  if (opts?.print) {
    const proc = Bun.spawn(args, { stdin: "inherit", stdout: "pipe", stderr: "inherit" })
    const output = await new Response(proc.stdout).text()
    await proc.exited
    return output
  }

  const proc = Bun.spawn(args, { stdin: "inherit", stdout: "inherit", stderr: "inherit" })
  await proc.exited
}

/** Open an interactive fish shell in the container, optionally in a specific directory. */
export async function shell(workdir?: string): Promise<void> {
  const args = ["container", "exec", "-it", "--user", USER]
  if (workdir) args.push("--workdir", containerPath(workdir))
  args.push(CONTAINER_NAME, "env", "TERM=xterm-256color", "fish", "--login")
  const proc = Bun.spawn(args, { stdin: "inherit", stdout: "inherit", stderr: "inherit" })
  await proc.exited
}

/** Run neofetch in the container. */
export async function info(): Promise<void> {
  const proc = Bun.spawn(
    ["container", "exec", "--user", USER, CONTAINER_NAME, "neofetch"],
    { stdin: "inherit", stdout: "inherit", stderr: "inherit" },
  )
  await proc.exited
}

/** Run a bash command in the container at the given workdir, capturing output. */
export async function exec(workdir: string, command: string): Promise<{ exitCode: number; stdout: string; stderr: string }> {
  const result = await $`container exec --user ${USER} --workdir ${containerPath(workdir)} ${CONTAINER_NAME} bash -c ${"export PATH=$HOME/.local/bin:$PATH; " + command}`.nothrow().quiet()
  return {
    exitCode: result.exitCode,
    stdout: result.stdout.toString().trim(),
    stderr: result.stderr.toString().trim(),
  }
}

/** Check if Claude is actively working in the given worktree (based on activity hook). */
export async function isClaudeActive(worktree: string, branch: string): Promise<boolean> {
  const file = `${dirname(worktree)}/.activity-${branch}`
  try {
    const content = await Bun.file(file).text()
    return content.trim() === "active"
  } catch {
    return false
  }
}

/** Remove the activity marker file for a worktree. */
export async function clearActivity(worktree: string, branch: string): Promise<void> {
  const file = `${dirname(worktree)}/.activity-${branch}`
  await Bun.file(file).unlink().catch(() => {})
}

/** Stop the container. */
export async function stop(): Promise<void> {
  await $`container stop ${CONTAINER_NAME}`.nothrow().quiet()
}

/** Stop and delete the container. */
export async function destroy(): Promise<void> {
  await stop()
  await $`container delete ${CONTAINER_NAME}`.nothrow().quiet()
}