name: Release SUB-OS

on:
  push:
    tags:
      - 'v*'
  workflow_dispatch:
    inputs:
      tag_name:
        description: 'Release Tag (e.g. v0.0.1-alpha)'
        required: true
        default: 'v0.0.1-alpha'

permissions:
  contents: write

jobs:
  build-and-release:
    name: Build & Publish Release
    runs-on: ubuntu-latest

    steps:
      - name: Checkout Code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Install Toolchain Dependencies
        run: |
          sudo apt-get update
          sudo apt-get install -y nasm gcc-x86-64-linux-gnu binutils-x86-64-linux-gnu make qemu-system-x86

      - name: Build SUB-OS Kernel & Bootable Disk Image
        run: |
          make clean
          make CROSS_COMPILE=x86_64-linux-gnu-

      - name: Verify Image and Prepare Release Artifacts
        run: |
          mkdir -p release-assets
          cp SUB-OS.img release-assets/
          cp build/kernel.elf release-assets/
          cp build/kernel.bin release-assets/
          cd release-assets
          sha256sum SUB-OS.img kernel.elf kernel.bin > SHA256SUMS.txt
          cat SHA256SUMS.txt
          cd ..

      - name: Determine Release Tag
        id: vars
        run: |
          if [ "${{ github.event_name }}" = "workflow_dispatch" ]; then
            TAG="${{ github.event.inputs.tag_name }}"
          else
            TAG="${GITHUB_REF#refs/tags/}"
          fi
          echo "tag=$TAG" >> $GITHUB_OUTPUT

      - name: Create GitHub Release
        uses: softprops/action-gh-release@v2
        with:
          tag_name: ${{ steps.vars.outputs.tag }}
          name: "SUB-OS ${{ steps.vars.outputs.tag }}"
          draft: false
          prerelease: true
          files: |
            release-assets/SUB-OS.img
            release-assets/kernel.elf
            release-assets/kernel.bin
            release-assets/SHA256SUMS.txt
          body: |
            # 🚀 SUB-OS ${{ steps.vars.outputs.tag }}
            
            Welcome to the first official alpha release of **SUB-OS**!
            
            **SUB-OS** is a 64-bit modular monolithic operating system built from scratch for the `x86_64` architecture, featuring modern Unix-like kernel architecture and the **LazyBox** multi-call userland binary suite.
            
            ---
            
            ### 🌟 Included Subsystems & Features
            
            - 🖥️ **64-Bit Bare-Metal Core**: Custom two-stage MBR bootloader with BIOS E820 memory mapping and 4GB 4-level PML4 identity paging.
            - ⚡ **Preemptive Scheduler**: 8254 PIT (100 Hz, 10ms resolution) driving Round-Robin task multitasking with atomic spinlocks & semaphores.
            - 🧠 **Memory Management**: 64-bit Physical Page Frame Allocator (4 KB bitmap) & Dynamic Kernel Heap (4 MB pool) with boundary tag coalescing.
            - 📁 **Virtual File System (VFS)**: POSIX-like VFS layer (`vfs_namei`), in-memory root RAMFS, synthetic `/dev` devfs, and `/proc` metrics procfs.
            - 🖧 **Hardware Drivers**:
              - **Char**: VGA Text mode, Virtual Terminals TTY1-4 with ANSI escape support, 16550 UART Serial (COM1), PS/2 Keyboard with scancode translation.
              - **Block**: ATA / IDE Hard Disk PIO driver (28-bit LBA).
              - **PCI**: Bus enumeration and BAR address space mapping.
              - **Network**: Intel 82540EM Gigabit Ethernet NIC with circular DMA RX/TX rings.
              - **Audio**: PC Speaker tone generator via PIT Channel 2.
            - 🌐 **Network Protocol Stack**: Ethernet L2, dynamic ARP table cache, IPv4 routing & checksums, and ICMP Echo client/server (`ping`).
            - 🔒 **Kernel Cryptography**: FIPS 180-4 SHA-256, RFC 1321 MD5, IEEE 802.3 CRC32, and Xorshift128+ CSPRNG.
            - 🧰 **LazyBox Multi-Call Userland**: 42 applets (`ls`, `cat`, `touch`, `mkdir`, `wc`, `ping`, `ifconfig`, `arp`, `sha256sum`, `md5sum`, `crc32`, `hdparm`, `uname`, `free`, `uptime`, `dmesg`, `sleep`, `clear`, `neofetch`, `echo`, `calc`) with command history and inline cursor editing.
            
            ---
            
            ### 🚀 Quick Start (Running with QEMU)
            
            Download `SUB-OS.img` attached below and launch using QEMU:
            
            ```bash
            qemu-system-x86_64 -drive format=raw,file=SUB-OS.img -nic model=e1000 -serial stdio
            ```
            
            ---
            
            ### 📦 Release Assets
            - `SUB-OS.img`: 1.5 MB bootable raw floppy/disk image.
            - `kernel.elf`: 64-bit Kernel ELF binary with symbol tables for debugging.
            - `kernel.bin`: Flat kernel binary payload loaded by stage 2 bootloader.
            - `SHA256SUMS.txt`: Cryptographic SHA-256 validation checksums.
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}