name: CI

on:
  push:
    branches: [main]
  pull_request:

env:
  CARGO_TERM_COLOR: always
  RUSTFLAGS: "-D warnings"

# Cancel a pull request's superseded runs instead of letting them burn
# to completion. This project rebases heavily — the ledger re-conflicts
# on nearly every merge — so a branch routinely takes several pushes
# while an earlier run is still going, and each of those runs is
# obsolete the moment the next push lands. macOS minutes are the
# expensive ones and the macOS leg is the critical path, so superseded
# runs are exactly where the waste concentrates.
#
# Scoped to pull requests deliberately. `github.event.pull_request.number`
# is empty for a push to `main`, so the fallback keys those runs by SHA:
# every `main` commit gets its own group and none can cancel another.
# Cancelling a `main` run would leave the branch-protection record
# ambiguous about a commit that has already landed — the one place this
# saving is not worth having.
concurrency:
  group: ci-${{ github.event.pull_request.number || github.sha }}
  cancel-in-progress: ${{ github.event_name == 'pull_request' }}

# Every job carries `timeout-minutes`. Without one a job inherits
# GitHub's 360-minute default, so a single hung test burns six hours —
# times four on the test matrix — and reports nothing useful at the end
# of it.
#
# The ceilings are justified against OBSERVED EXECUTION, and the
# numbers are a reading rather than a constant, so re-measure before
# trusting them:
#
#   * observed max, 25-run window: 17 min (macOS/luajit)
#   * observed max, 12-run window: 15.8 min (same job)
#   * every other job: under 4 min
#
# `timeout-minutes` counts EXECUTION, not queue time — a 33-minute
# wall-clock run in that window executed its longest job in 17 — so no
# run in the observed history would have been killed by these values.
#
# The exposure is the case the window does NOT contain: a COLD CACHE.
# A stable-toolchain bump invalidates Swatinem's key on every leg at
# once, and a cold macOS debug build of this workspace plus the suite is
# the plausible way a HEALTHY run exceeds its ceiling. The test job
# therefore gets 35 rather than 25 — roughly 2x its observed max — while
# everything else keeps 25 against a sub-4-minute observed max, except
# `m6-perf-gates`, which keeps its own tighter 15.
#
# DIAGNOSIS, WRITTEN BEFORE IT HAPPENS: four test legs timing out
# simultaneously, shortly after a Rust release, is a cold cache and not
# a hang. Rerun, or raise this number. A single leg timing out while its
# siblings pass is the hang case these ceilings exist to catch.
#
# This is also the gate that has to exist before the basedpyright-class
# hang can ever be armed — see `PMACS_REQUIRE_PYRIGHT`, deliberately
# never set, in the test job below. 35 still beats the 360-minute
# default by an order of magnitude.
jobs:
  fmt:
    name: Format
    runs-on: ubuntu-latest
    timeout-minutes: 25
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
        with:
          components: rustfmt
      - run: cargo fmt --all --check

  clippy:
    name: Lint (${{ matrix.lua }})
    runs-on: ubuntu-latest
    timeout-minutes: 25
    strategy:
      fail-fast: false
      matrix:
        # mlua's Lua-flavor features are mutually exclusive, so we can't
        # use --all-features. Run clippy under each supported flavor.
        lua: [luajit, lua54]
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
        with:
          components: clippy
      - uses: Swatinem/rust-cache@v2
      - run: cargo clippy --all-targets --no-default-features --features ${{ matrix.lua }} -- -D warnings
      # pmacs-gpu is Lua-flavor-independent (it depends on pmacs-protocol,
      # not pmacs), so the root-package clippy above never lints it. Lint
      # it explicitly or its warnings slip through CI (audit F-001).
      - run: cargo clippy -p pmacs-gpu --all-targets -- -D warnings
      # pmacs-protocol is likewise never linted by the root-package
      # clippy above: the workspace default member is only `pmacs`. The
      # local `--workspace` gate covers it, so it passes today — CI has
      # simply never checked, and a warning introduced through a
      # protocol-only PR would reach `main` unseen.
      - run: cargo clippy -p pmacs-protocol --all-targets -- -D warnings

  gpu-render:
    name: GPU Render (headless)
    runs-on: ubuntu-latest
    timeout-minutes: 25
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2
      # The headless render harness (audit F-014) needs a Vulkan adapter;
      # the runner has no GPU, so install the mesa software rasterizer
      # (lavapipe). This job also runs pmacs-gpu's other tests, which the
      # workspace test job (root package only) never executes.
      - name: Install lavapipe (Vulkan software rasterizer)
        run: |
          sudo apt-get update
          sudo apt-get install -y mesa-vulkan-drivers vulkan-tools
      - name: Confirm a Vulkan adapter is present
        run: |
          ls -la /usr/share/vulkan/icd.d/ || true
          vulkaninfo --summary || true
      - name: pmacs-gpu tests (render harness included)
        env:
          # Force the Vulkan backend so wgpu uses lavapipe. Do NOT set
          # VK_ICD_FILENAMES — the loader's default ICD discovery already
          # finds lavapipe (vulkaninfo above proves it), and pinning a
          # path that doesn't match the runner hides every ICD. The
          # PMACS_REQUIRE_GPU guard turns a missing adapter into a hard
          # failure so a broken setup can't pass as a silent skip.
          WGPU_BACKEND: vulkan
          LIBGL_ALWAYS_SOFTWARE: "1"
          PMACS_REQUIRE_GPU: "1"
        run: cargo test -p pmacs-gpu -- --test-threads=1

  test:
    name: Test (${{ matrix.os }} / ${{ matrix.lua }})
    runs-on: ${{ matrix.os }}
    # 35, not 25: this is the only job whose observed max is minutes
    # rather than seconds, and the only one a cold cache can plausibly
    # push past a 25-minute ceiling on all four legs at once. See the
    # note above `jobs:` for the measurements and the cold-cache
    # diagnosis.
    timeout-minutes: 35
    strategy:
      fail-fast: false
      matrix:
        os: [ubuntu-latest, macos-latest]
        lua: [luajit, lua54]
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2
      # Arm the external-tool-gated tests (see `TEST_IMPROVEMENT.md`
      # §1.2). Before this step nothing installed these tools, so every
      # test guarded on them returned early and reported GREEN without
      # executing its body — a whole block of real-language-server and
      # multi-shell coverage that had never once run in CI. Installing
      # them is only half the fix; the `PMACS_REQUIRE_*` variables below
      # are what turn a future missing tool back into a failure instead
      # of silently restoring the vacuum.
      #
      # Linux only for now, deliberately. macOS would need the brew
      # equivalents and roughly doubles the install cost on the slowest
      # leg of the matrix; arming one platform already converts these
      # from never-executed to executed, and the second is incremental.
      # The tests still skip cleanly on macOS because the variables are
      # unset there.
      - name: Install external tools that gate acceptance tests (Linux)
        if: runner.os == 'Linux'
        run: |
          sudo apt-get update
          sudo apt-get install -y clangd zsh fish lua5.4
          # `locate_lua` looks for `lua` or `luajit` by name; the
          # distro package installs `lua5.4` only.
          sudo ln -sf "$(command -v lua5.4)" /usr/local/bin/lua
          # rust-analyzer belongs HERE, not on the shared toolchain
          # step. `components:` there applies to every matrix leg, so it
          # would install the binary on macOS too — and *presence*, not
          # PMACS_REQUIRE_LSP, is what decides whether a gated test body
          # runs. That would have executed the rust-analyzer tests on
          # macOS for the first time ever, on the legs that are both the
          # CI critical path and the documented flake surface, while
          # this lane's text claimed Linux only.
          rustup component add rust-analyzer
          # Versions are PINNED. `@latest` and bare `npm install -g`
          # make CI behaviour drift with upstream releases: a bad gopls
          # or yaml-language-server publish then breaks CI with no
          # commit in this repository to bisect against.
          go install golang.org/x/tools/gopls@v0.16.2
          echo "$(go env GOPATH)/bin" >> "$GITHUB_PATH"
          npm install -g vscode-langservers-extracted@4.10.0 \
                         yaml-language-server@1.15.0
      - run: cargo build --all-targets --no-default-features --features ${{ matrix.lua }}
      # Several acceptance binaries spawn real daemon / PTY child
      # processes. Keep the harness serial so macOS runners do not
      # expose cross-test process lifecycle races that are unrelated
      # to the behavior under test.
      #
      # PMACS_REQUIRE_* make a missing tool fatal rather than a silent
      # skip, exactly as PMACS_REQUIRE_GPU already does for the headless
      # render job. Set only where the install step ran.
      #
      # PMACS_REQUIRE_PYRIGHT is deliberately NOT set and basedpyright
      # is deliberately NOT installed: that test has no timeout and
      # hangs forever (root cause is the non-interruptible reader-thread
      # join in `RuntimeHandles::drop`, already a named deferral in
      # `src/process.rs`). This job has no `timeout-minutes`, so arming
      # it today would trade a vacuous green for a six-hour hang on four
      # legs. It gets armed after the hang fix and the CI timeouts land,
      # and its own variable exists so that flip is one line.
      - run: cargo test --all-targets --no-default-features --features ${{ matrix.lua }} -- --test-threads=1
        env:
          PMACS_REQUIRE_LSP: ${{ runner.os == 'Linux' && '1' || '' }}
          PMACS_REQUIRE_SHELLS: ${{ runner.os == 'Linux' && '1' || '' }}
          PMACS_REQUIRE_LUA: ${{ runner.os == 'Linux' && '1' || '' }}
      - run: cargo test --doc --no-default-features --features ${{ matrix.lua }}
      # The workspace default member is only the root `pmacs` package, so
      # the runs above never execute pmacs-protocol's own tests — the
      # shared wire format (encode/decode, transport framing) the daemon,
      # TUI, and GPU all depend on. Run them explicitly (Lua-flavor
      # independent, so once is enough; runs on every matrix leg cheaply
      # off the shared cache).
      - run: cargo test -p pmacs-protocol --all-targets

  acceptance:
    name: M1 Acceptance Gates
    runs-on: ubuntu-latest
    timeout-minutes: 25
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2
      - name: perf, memory, and 30s fuzz gates
        run: cargo test --release --test acceptance -- --ignored --nocapture --test-threads=1

  m4-perf-gates:
    name: M4 Perf Gates
    runs-on: ubuntu-latest
    timeout-minutes: 25
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2
      - name: tree-sitter parse + highlight latency budgets
        run: cargo test --release --test m4_acceptance -- --ignored --nocapture --test-threads=1

  # m5-perf-gates: luajit-only by design.
  # The keystroke-to-render gate measures protocol-path latency (Unix
  # socket frontend ↔ daemon RTT plus the daemon's keymap-dispatch /
  # buffer-mutate / repaint pipeline). Lua flavor is irrelevant — the
  # measured path doesn't enter the Lua VM. Matrixing over flavors
  # doubles CI cost without adding signal. If a future perf gate
  # measures Lua-touching code paths (command dispatch via Lua,
  # hook invocation), revisit then.
  m5-perf-gates:
    name: M5 Perf Gates
    runs-on: ubuntu-latest
    timeout-minutes: 25
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2
      - name: keystroke-to-render p99 over loopback LocalSocket
        run: cargo test --release --test m5_perf_acceptance -- --ignored --nocapture

  # m6-perf-gates: luajit-only by design. The M6.6/M6.7 gates measure
  # rope-append throughput, RSS ceiling, cancel-response latency,
  # scrollback navigation latency, and scrollback search latency —
  # none of which exercise the Lua VM's hot path differently across
  # flavors. Same reasoning as m5-perf-gates above.
  #
  # --test-threads=1 is required: the M6.6 RSS-ceiling gate samples
  # process-wide /proc/self/status, and concurrent ingest / scrollback
  # populate from sibling tests inflate that reading. Serializing
  # gives each test a clean baseline. The wall-clock cost of serial
  # execution (~5 minutes) is acceptable for a perf-gates job that
  # only runs on push/PR.
  m6-perf-gates:
    name: M6 Perf Gates
    runs-on: ubuntu-latest
    timeout-minutes: 15
    steps:
      - uses: actions/checkout@v4
      - uses: dtolnay/rust-toolchain@stable
      - uses: Swatinem/rust-cache@v2
      - name: ingest rate, RSS ceiling, cancel p99, navigation p99, search p99
        env:
          # Full cancel profile remains the test default. Hosted CI has
          # an effective five-minute ceiling for this job and variable
          # PTY throughput, so keep the per-PR profile short and stable.
          PMACS_M6_INGEST_MIN_BYTES_PER_SEC: "67108864"
          PMACS_M6_CANCEL_TRIALS: "30"
          PMACS_M6_CANCEL_MAX_DELAY_MS: "500"
        run: cargo test --release --test m6_perf_acceptance -- --ignored --nocapture --test-threads=1