defmodule Mix.Tasks.LiveInteractionContracts.Test do
  @shortdoc "Run the LiveView interaction conformance harness and assert the fuse"
  @moduledoc """
  Boots a bundled LiveView fixture app against a chosen LiveView version, drives
  it with Playwright in real browsers, and asserts the frozen classification
  (green machines green, red fixtures red, deterministic). Exits non-zero on any
  regression — this is the fuse.

      mix live_interaction_contracts.test
      mix live_interaction_contracts.test --browser chromium
      mix live_interaction_contracts.test --suite combobox
      mix live_interaction_contracts.test --lv "github:phoenixframework/phoenix_live_view#main"

  Options:

    * `--suite`   harness | cursor | combobox | dialog-adapter | popover | menu |
      tooltip | island  (default: harness — the one with the ledger + fuse)
    * `--browser` chromium | firefox | webkit  (default: all three)
    * `--lv`      LiveView version spec (default: host project's version, else 1.2.7)
    * `--port`    fixture HTTP port (default per suite)

  Requires `elixir`, `node`, and Playwright browsers (`npx playwright install`)
  on PATH. Intended for `only: [:dev, :test]` use.
  """
  use Mix.Task

  @suites %{
    "harness" => %{dir: "harness", app: "app.exs", driver: "suite.mjs", result: "results.json", port: 4123, assert: true, ledger: true},
    "cursor" => %{dir: "cursor-spike", app: "app.exs", driver: "spike.mjs", port: 4126, assert: false, ledger: false},
    "combobox" => %{dir: "combobox-spike", app: "app.exs", driver: "spike.mjs", port: 4127, assert: false, ledger: false},
    # Adapter suite: the driver self-asserts 7/7 (its own fuse), so exit code carries it.
    "dialog-adapter" => %{dir: "dialog-adapter-spike", app: "app.exs", driver: "spike.mjs", port: 4128, assert: false, ledger: false},
    # Reference component: dogfoods the shipped <.popover> + hook; self-asserts 6/6.
    "popover" => %{dir: "popover-reference", app: "app.exs", driver: "driver.mjs", port: 4129, assert: false, ledger: false},
    # Reference component: dogfoods the shipped <.menu> + hook (popover + cursor); self-asserts 7/7.
    "menu" => %{dir: "menu-reference", app: "app.exs", driver: "driver.mjs", port: 4130, assert: false, ledger: false},
    # Reference component: dogfoods the shipped <.tooltip> + hook (popover + hover/focus trigger); self-asserts 7/7.
    "tooltip" => %{dir: "tooltip-reference", app: "app.exs", driver: "driver.mjs", port: 4131, assert: false, ledger: false},
    "select" => %{dir: "select-reference", app: "app.exs", driver: "driver.mjs", port: 4134, assert: false, ledger: false},
    # Reference component: dogfoods the shipped <.combobox> + hook + Channel guard; self-asserts 9/9.
    "combobox-reference" => %{dir: "combobox-reference", app: "app.exs", driver: "driver.mjs", port: 4135, assert: false, ledger: false},
    # Contract proof: client-built children need phx-update=ignore or any patch wipes them.
    "island" => %{dir: "island-survival-spike", app: "app.exs", driver: "driver.mjs", port: 4132, assert: false, ledger: false}
  }

  @impl true
  def run(argv) do
    {opts, _, _} =
      OptionParser.parse(argv,
        strict: [suite: :string, browser: :string, lv: :string, port: :integer]
      )

    suite_name = opts[:suite] || "harness"
    suite =
      @suites[suite_name] ||
        Mix.raise("unknown --suite #{suite_name} (#{@suites |> Map.keys() |> Enum.sort() |> Enum.join("|")})")
    lv = LiveInteractionContracts.resolve_lv_spec(opts[:lv])
    port = opts[:port] || suite.port
    browser = opts[:browser]

    priv = LiveInteractionContracts.priv_dir()
    fixture = Path.join(priv, suite.dir)
    # Generated ledger goes to the invocation cwd (the consuming project root),
    # never into _build where priv resolves.
    root = File.cwd!()

    Mix.shell().info("== live_interaction_contracts: suite=#{suite_name} lv=#{lv} browser=#{browser || "all"} port=#{port}")
    Mix.shell().info("== fixture: #{fixture}")

    script = orchestration(fixture, suite, port, lv, browser, root)

    case System.cmd("bash", ["-c", script], into: IO.stream(:stdio, :line), stderr_to_stdout: true) do
      {_, 0} -> Mix.shell().info("== conformance fuse OK")
      {_, code} -> Mix.raise("conformance fuse tripped (exit #{code})")
    end
  end

  # Reuse the proven boot/drive/assert/teardown shell pattern. Kills by port so no
  # orphaned BEAM node survives the fixture's Mix.install launcher.
  defp orchestration(fixture, suite, port, lv, browser, root) do
    only = if browser, do: "ONLY_BROWSER=#{sh(browser)}", else: ""
    assert_step = if suite.assert, do: "node ci-assert.mjs; ASSERT=$?", else: "ASSERT=$SUITE"
    result_cleanup = if suite[:result], do: "rm -f #{sh(suite.result)}", else: ":"
    # Ledger failure trips the fuse too: a green fuse with a stale/missing ledger
    # would be a false pass (the README promises test == run + regenerate + assert).
    ledger_step = if suite.ledger, do: "LEDGER_DIR=#{sh(root)} RESULTS_FILE=#{sh(suite.result)} node ledger.mjs; LEDGER=$?", else: "LEDGER=0"

    """
    set -o pipefail
    cd #{sh(fixture)}
    # Wait until the port is GENUINELY free before booting. A dying BEAM can still
    # hold the port (and briefly answer curl) for more than a second after SIGTERM;
    # booting into that race gave an :eaddrinuse crash + a stale-server goto timeout.
    port_free() { for i in $(seq 1 60); do lsof -nP -t -iTCP:#{port} -sTCP:LISTEN >/dev/null 2>&1 || return 0; sleep 0.5; done; return 1; }
    kill $(lsof -nP -t -iTCP:#{port} -sTCP:LISTEN) 2>/dev/null || true
    port_free || { echo "PORT #{port} STILL IN USE AFTER 30s"; exit 3; }
    LV_SPEC=#{sh(lv)} PORT=#{port} VERSIONS_OUT=versions.json elixir #{suite.app} > server.log 2>&1 &
    APP_PID=$!
    # Only the server we just booted can answer now (port was confirmed free).
    for i in $(seq 1 120); do curl -sf -o /dev/null http://127.0.0.1:#{port}/ && break; kill -0 $APP_PID 2>/dev/null || { echo "FIXTURE PROCESS DIED"; tail -30 server.log; exit 2; }; sleep 2; done
    if ! curl -sf -o /dev/null http://127.0.0.1:#{port}/; then echo "FIXTURE FAILED TO BOOT"; tail -30 server.log; exit 2; fi
    #{result_cleanup}
    #{only} PORT=#{port} node #{suite.driver}; SUITE=$?
    #{ledger_step}
    #{assert_step}
    kill $(lsof -nP -t -iTCP:#{port} -sTCP:LISTEN) 2>/dev/null || true
    port_free || true   # leave the port clean for the next suite invocation
    RESULT=$SUITE
    if [ "$RESULT" -eq 0 ]; then RESULT=${ASSERT:-0}; fi
    if [ "$RESULT" -eq 0 ] && [ "$LEDGER" -ne 0 ]; then echo "LEDGER GENERATION FAILED (exit $LEDGER)"; RESULT=$LEDGER; fi
    exit $RESULT
    """
  end

  # Single-quote a value for safe interpolation into the bash script (paths with
  # spaces, lv specs with # / &, etc.).
  defp sh(value), do: "'" <> String.replace(to_string(value), "'", "'\\''") <> "'"
end