# Release, Go library. Runs on version tags (v1.2.3) pushed to main.
#
# A library ships no binaries, so there is no build matrix and no smoke test: the release
# carries the CHANGELOG section as its body and nothing else. The gates still run first,
# in their own job and once, minus the race detector: race never runs on a push path or a
# tag, and the local gate raced this tree before the tag was cut. The write permission
# sits on the release job alone, and the version contract these steps implement is in the
# `release` skill.
#
# Every step is one command, so the step that fails is the gate that failed, and no shell
# option has to be trusted for the run to stop. The scripted steps are Perl, not shell and
# not Python: Perl behaves the same on both runner images, there is no bashism to trip over
# on ash, and it is one language instead of two. The Perl uses builtins only, because
# Fedora packages the Perl modules separately and nothing beyond `perl` itself may be
# assumed present, which is why the release body is escaped by hand and curl is the
# transport.
name: Release

on:
  push:
    tags: ["v*"]

env:
  # The box is shared with the forge, so parallelism is bounded on purpose. The gates job
  # needs it most, since it runs the suite.
  GOFLAGS: -p=1
  GOMAXPROCS: "2"

jobs:
  gates:
    runs-on: fedora
    timeout-minutes: 10
    steps:
      - uses: actions/checkout@v7

      - uses: actions/setup-go@v6
        with:
          # The module is the source of truth for the version, so it cannot drift.
          go-version-file: go.mod
          cache: true

      - name: Install Perl
        # Perl for the steps below. The install is a no-op where the package
        # is already present.
        run: dnf install -y perl

      - name: Validate the tag
        env:
          VERSION: ${{ gitea.ref_name }}
        run: |
          perl -e '
            my $v = $ENV{VERSION} // q{};
            $v =~ m{^v[0-9]+(\.[0-9]+){0,2}([-+].*)?$}
              or die qq{ERROR: expected a semver tag like v1.2.3, got: $v\n};
            print qq{tag $v\n};
          '

      - name: Format
        run: |
          perl -e '
            open(my $g, q{-|}, q{gofmt}, q{-l}, q{.}) or die qq{gofmt: $!};
            my @bad = <$g>;
            close($g);
            print @bad;
            exit(@bad ? 1 : 0);
          '

      - name: Vet
        run: go vet ./...

      - name: Modernise
        # Exits non-zero when it has something to rewrite, so it needs no output capture.
        run: go fix -diff ./...

      - name: Build
        run: go build ./...

      - name: Tests
        # Keep the pattern equal to `packages` in the project's justfile.
        run: go test -count=1 -timeout 30m -coverprofile=coverage.out ./...

      - name: Coverage floor
        run: |
          perl -e '
            open(my $c, q{-|}, q{go}, q{tool}, q{cover}, q{-func=coverage.out}) or die qq{cover: $!};
            my $total;
            while (my $l = <$c>) { $total = $1 if $l =~ m{^total:\s+\S+\s+([0-9.]+)%} }
            close($c);
            die qq{no total line in coverage.out\n} unless defined $total;
            printf qq{Total coverage: %s%%\n}, $total;
            exit($total < 80 ? 1 : 0);
          '

  release:
    runs-on: fedora
    timeout-minutes: 15
    needs: gates
    permissions:
      # contents: read is required for the checkout: a job that declares any
      # permissions gets a token scoped to exactly those, and releases: write
      # alone leaves the fetch with no read access, which Gitea answers with
      # a 404 "Repository not found". Verified on the instance 2026-09-16.
      contents: read
      releases: write
    steps:
      - uses: actions/checkout@v7

      - name: Install Perl
        # The runner images are minimal and Perl is not guaranteed. The install is a
        # no-op where it is already present; drop this step once verified on the box.
        run: dnf install -y perl

      - name: Extract the CHANGELOG section
        env:
          VERSION: ${{ gitea.ref_name }}
        run: |
          # Each step derives what it needs from the tag, so no value has to travel between
          # jobs. The separator after the version is never read, so the heading format's
          # separator stays free.
          perl -e '
            my $v = $ENV{VERSION} // q{};
            $v =~ s{^v}{};
            open(my $vout, q{>}, q{version-no-v.txt}) or die qq{version-no-v.txt: $!};
            print $vout $v;
            close($vout);
            open(my $in, q{<}, q{CHANGELOG.md}) or die qq{CHANGELOG.md: $!};
            my @lines = <$in>;
            close($in);
            my ($start, $end) = (-1, scalar @lines);
            for my $i (0 .. $#lines) {
              if ($start < 0) { $start = $i if $lines[$i] =~ m{^##\s+\[\Q$v\E\]} }
              elsif ($lines[$i] =~ m{^##\s+\[}) { $end = $i; last }
            }
            $start >= 0 or die qq{ERROR: no CHANGELOG section for $v, expected a heading like: ## [$v] - YYYY-MM-DD\n};
            my @body = grep { m{\S} } @lines[$start + 1 .. $end - 1];
            @body or die qq{ERROR: the CHANGELOG section for $v is empty\n};
            open(my $out, q{>}, q{release-body.md}) or die qq{release-body.md: $!};
            print $out @body;
            close($out);
            printf qq{notes for %s: %d lines\n}, $v, scalar @body;
          '

      - name: Build the release request
        run: |
          perl -e '
            open(my $vin, q{<}, q{version-no-v.txt}) or die qq{version-no-v.txt: $!};
            my $v = <$vin>;
            close($vin);
            chomp $v;
            open(my $in, q{<:raw}, q{release-body.md}) or die qq{release-body.md: $!};
            my $body = do { local $/; <$in> };
            close($in);
            # Byte-oriented escaping: JSON is UTF-8, so non-ASCII passes through and only the
            # characters JSON forbids are rewritten.
            $body =~ s/([\\"])/\\$1/g;
            $body =~ s/\t/\\t/g;
            $body =~ s/\r//g;
            $body =~ s/\n/\\n/g;
            $body =~ s/([\x00-\x08\x0b\x0c\x0e-\x1f])/sprintf(q{\u%04x}, ord($1))/ge;
            my $json = sprintf(qq{{"tag_name":"v%s","name":"v%s","body":"%s","draft":false,"prerelease":false}}, $v, $v, $body);
            open(my $out, q{>}, q{release.json}) or die qq{release.json: $!};
            print $out $json;
            close($out);
            print qq{release.json written for v$v\n};
          '

      - name: Create the release
        env:
          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
          GITEA_SERVER_URL: ${{ gitea.server_url }}
          GITEA_REPOSITORY: ${{ gitea.repository }}
        run: |
          perl -e '
            my @cmd = (q{curl}, q{-sS}, q{-o}, q{response.json}, q{-w}, q{%{http_code}},
              q{-H}, qq{Authorization: token $ENV{GITEA_TOKEN}},
              q{-H}, q{Content-Type: application/json},
              q{-X}, q{POST},
              qq{$ENV{GITEA_SERVER_URL}/api/v1/repos/$ENV{GITEA_REPOSITORY}/releases},
              q{--data-binary}, q{@release.json});
            open(my $curl, q{-|}, @cmd) or die qq{curl: $!};
            my $code = <$curl>;
            my $ok = close($curl);
            my $exit = $? >> 8;
            $code = defined $code ? $code : q{};
            $ok or die qq{ERROR: curl failed (exit $exit) calling $ENV{GITEA_SERVER_URL}\n};
            open(my $r, q{<:raw}, q{response.json}) or die qq{response.json: $!};
            my $body = do { local $/; <$r> };
            close($r);
            $code eq q{201} or die qq{ERROR: the release was not created, HTTP $code: $body\n};
            $body =~ m{"id"\s*:\s*([0-9]+)} or die qq{ERROR: no release id in the response: $body\n};
            print qq{release id $1\n};
          '