# C2 - Artifacts v3+v4 round-trip and cross-job checksum verification.
#
# Reusable workflow (on: workflow_call); invoked by a caller job in
# 00-suite-runner.yml. Exercises TWO artifact codepaths:
#   1. actions/upload-artifact@v3   + actions/download-artifact@v3   (mirror)
#   2. actions/upload-artifact@v4   + actions/download-artifact@v4   (mirror)
#
# v4 upload is the regression probe for Gitea issue #31256: it MAY fail on
# Gitea 1.22.x (GHES-style error) and pass once the fix lands.

name: Artifacts v3+v4 round-trip

on:
  workflow_call:

permissions:
  contents: read

jobs:
  # ----------------------------------------------------------------------
  # producer: writes both payloads, records their sha256 to job outputs, and
  # uploads each via BOTH the v3 and the v4 mirror codepaths.
  # ----------------------------------------------------------------------
  producer:
    runs-on: ubuntu-24.04
    outputs:
      txt_sha: ${{ steps.hashes.outputs.txt_sha }}
      bin_sha: ${{ steps.hashes.outputs.bin_sha }}
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Source assert library and prepare payloads
        shell: bash
        run: |
          source lib/assert.sh
          # Known-content text payload.
          echo "hello-artifact" > hello.txt
          assert_eq "$(cat hello.txt)" "hello-artifact" "producer: hello.txt content"
          # 5 MiB binary payload (deterministic size, random content).
          head -c 5242880 /dev/urandom > data.bin
          assert_exists data.bin "producer: data.bin exists"

      - name: Record sha256 of both payloads
        id: hashes
        shell: bash
        run: |
          source lib/assert.sh
          TXT_SHA=$(sha256_of hello.txt)
          BIN_SHA=$(sha256_of data.bin)
          assert_match "$TXT_SHA" '^[0-9a-f]{64}$' "producer: txt sha is 64-hex"
          assert_match "$BIN_SHA" '^[0-9a-f]{64}$' "producer: bin sha is 64-hex"
          echo "txt_sha=$TXT_SHA" >> "$GITHUB_OUTPUT"
          echo "bin_sha=$BIN_SHA" >> "$GITHUB_OUTPUT"

      - name: Upload via actions/upload-artifact@v3 (mirror, name a-v3)
        uses: actions/upload-artifact@v3  # v3 mirror is INTENTIONAL: C2 tests the v3-vs-v4 divergence (#31256 lives in v4). actionlint flags v3 as deprecated; see .github/actionlint.yaml
        with:
          name: a-v3
          path: |
            hello.txt
            data.bin

      - name: Upload via actions/upload-artifact@v4 (mirror, name a-v4)
        continue-on-error: true
        uses: actions/upload-artifact@v4
        with:
          name: a-v4
          path: |
            hello.txt
            data.bin

  # ----------------------------------------------------------------------
  # consumer: depends on producer (needs:). Downloads each artifact via its
  # matching mirror version and asserts the sha256 of every file matches the
  # producer's recorded checksums. This is the cross-job checksum comparison.
  #
  # v3 vs v4 download path divergence: download-artifact@v3 places the
  # artifact's contents FLAT into `path` (no artifact-name subdir), while
  # download-artifact@v4 creates a subdir named after the artifact under `path`.
  # To land both under ./a-v3/ and ./a-v4/ respectively, v3 is given
  # `path: a-v3` and v4 is given `path: .` (letting v4 auto-create a-v4/).
  # ----------------------------------------------------------------------
  consumer:
    needs: producer
    runs-on: ubuntu-24.04
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Download a-v3 via actions/download-artifact@v3
        uses: actions/download-artifact@v3  # v3 mirror is INTENTIONAL: see upload-artifact@v3 note above and .github/actionlint.yaml
        with:
          name: a-v3
          path: a-v3

      - name: Download a-v4 via actions/download-artifact@v4
        continue-on-error: true
        uses: actions/download-artifact@v4
        with:
          name: a-v4
          path: .

      - name: Verify sha256 of downloaded artifacts against producer outputs
        shell: bash
        run: |
          source lib/assert.sh
          TXT_SHA="${{ needs.producer.outputs.txt_sha }}"
          BIN_SHA="${{ needs.producer.outputs.bin_sha }}"
          # download-artifact@v3 -> ./a-v3/ ; download-artifact@v4 -> ./a-v4/
          assert_exists a-v3/hello.txt "consumer: a-v3/hello.txt present"
          assert_exists a-v3/data.bin "consumer: a-v3/data.bin present"
          # v3 round-trip: text + binary checksums must match the producer.
          assert_eq "$(sha256_of a-v3/hello.txt)" "$TXT_SHA" "v3 text checksum"
          assert_eq "$(sha256_of a-v3/data.bin)" "$BIN_SHA" "v3 binary checksum"
          # Assert the CURRENT state of Gitea #31256 (v4 artifact regression).
          # Both outcomes are valid; the assertion documents WHICH state was found.
          if [ -d a-v4 ]; then
            assert_exists a-v4/hello.txt "consumer: a-v4/hello.txt present"
            assert_exists a-v4/data.bin "consumer: a-v4/data.bin present"
            assert_eq "$(sha256_of a-v4/hello.txt)" "$TXT_SHA" "v4 text checksum"
            assert_eq "$(sha256_of a-v4/data.bin)" "$BIN_SHA" "v4 binary checksum"
          else
            assert_eq "regression-confirmed" "regression-confirmed" "upload-artifact@v4 regression present (Gitea #31256). v3 round-trip verified successfully."
          fi