name: Firmware CI

on:
  push:
    paths:
      - 'firmware/**'
      - '.github/workflows/firmware-ci.yml'
  pull_request:
    paths:
      - 'firmware/**'
      - '.github/workflows/firmware-ci.yml'

jobs:
  build:
    name: Build ESP32-S3 Firmware
    runs-on: ubuntu-latest
    container:
      image: espressif/idf:v5.2

    steps:
      - uses: actions/checkout@v4

      - name: Build firmware
        working-directory: firmware/esp32-csi-node
        run: |
          . $IDF_PATH/export.sh
          idf.py set-target esp32s3
          idf.py build

      - name: Verify binary size (< 950 KB gate)
        working-directory: firmware/esp32-csi-node
        run: |
          BIN=build/esp32-csi-node.bin
          SIZE=$(stat -c%s "$BIN")
          MAX=$((950 * 1024))
          echo "Binary size: $SIZE bytes ($(( SIZE / 1024 )) KB)"
          echo "Size limit:  $MAX bytes (950 KB — includes Tier 3 WASM runtime)"
          if [ "$SIZE" -gt "$MAX" ]; then
            echo "::error::Firmware binary exceeds 950 KB size gate ($SIZE > $MAX)"
            exit 1
          fi
          echo "Binary size OK: $SIZE <= $MAX"

      - name: Verify flash image integrity
        working-directory: firmware/esp32-csi-node
        run: |
          ERRORS=0
          BIN=build/esp32-csi-node.bin

          # Check binary exists and is non-empty.
          if [ ! -s "$BIN" ]; then
            echo "::error::Binary not found or empty"
            exit 1
          fi

          # Check partition table magic (0xAA50 at offset 0).
          PT=build/partition_table/partition-table.bin
          if [ -f "$PT" ]; then
            MAGIC=$(xxd -l2 -p "$PT")
            if [ "$MAGIC" != "aa50" ]; then
              echo "::warning::Partition table magic mismatch: $MAGIC (expected aa50)"
              ERRORS=$((ERRORS + 1))
            fi
          fi

          # Check bootloader exists.
          BL=build/bootloader/bootloader.bin
          if [ ! -s "$BL" ]; then
            echo "::warning::Bootloader binary missing or empty"
            ERRORS=$((ERRORS + 1))
          fi

          # Verify non-zero data in binary (not all 0xFF padding).
          NONZERO=$(xxd -l 1024 -p "$BIN" | tr -d 'f' | wc -c)
          if [ "$NONZERO" -lt 100 ]; then
            echo "::error::Binary appears to be mostly padding (non-zero chars: $NONZERO)"
            ERRORS=$((ERRORS + 1))
          fi

          if [ "$ERRORS" -gt 0 ]; then
            echo "::warning::Flash image verification completed with $ERRORS warning(s)"
          else
            echo "Flash image integrity verified"
          fi

      - name: Check QEMU ESP32-S3 support status
        run: |
          echo "::notice::ESP32-S3 QEMU support is experimental in ESP-IDF v5.4. "
          echo "Full smoke testing requires QEMU 8.2+ with xtensa-esp32s3 target."
          echo "See: https://github.com/espressif/qemu/wiki"

      - name: Upload firmware artifact
        uses: actions/upload-artifact@v4
        with:
          name: esp32-csi-node-firmware
          path: |
            firmware/esp32-csi-node/build/esp32-csi-node.bin
            firmware/esp32-csi-node/build/bootloader/bootloader.bin
            firmware/esp32-csi-node/build/partition_table/partition-table.bin
          retention-days: 30