#!/bin/bash
# build.sh — build the n-OS-tr live ISO
set -euo pipefail

REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
WORKSPACE_ISO_DIR="$REPO_ROOT/iso"
WORKSPACE_ISO="$WORKSPACE_ISO_DIR/live-image-amd64.hybrid.iso"
BUILD_LOG="$WORKSPACE_ISO_DIR/build.log"
ARTIFACTS_DIR="$WORKSPACE_ISO_DIR/config/includes.chroot_before_packages/live-artifacts"
BUILD_BINARIES_SCRIPT="$REPO_ROOT/scripts/build-binaries.sh"
ISSUE_TEMPLATE_PATH="$REPO_ROOT/iso/config/templates/issue.template"

CLEAN_REQUESTED=0
# Fast iteration defaults:
# - skip includes/ binary compilation
# - skip re-config if existing lb config is present
# - disallow network downloads during lb build
ISO_ONLY=1
RECONFIGURE=0
OFFLINE=1

usage() {
    cat >&2 <<'EOF'
usage: ./build.sh [options]

Default (no flags): fastest iteration build
  - no includes/ binary rebuild
  - no lb reconfigure if already configured
  - offline build (no new downloads)

options:
  --with-binaries   rebuild includes/ artifacts before ISO build
  --reconfigure     run lb config before build
  --online          allow network downloads during lb build
  --clean           remove iso/.build cache, chroot, binary outputs first
  --iso-only        compatibility alias (same as default fast mode)
  -h, --help        show this help
EOF
}

while [[ "$#" -gt 0 ]]; do
    case "$1" in
        --clean)
            CLEAN_REQUESTED=1
            shift
            ;;
        --iso-only)
            ISO_ONLY=1
            shift
            ;;
        --with-binaries)
            ISO_ONLY=0
            shift
            ;;
        --reconfigure)
            RECONFIGURE=1
            shift
            ;;
        --online)
            OFFLINE=0
            shift
            ;;
        -h|--help)
            usage
            exit 0
            ;;
        *)
            echo "[build.sh] unsupported arguments: $*" >&2
            usage
            exit 2
            ;;
    esac
done

home_opts="$(findmnt -n -o OPTIONS /home 2>/dev/null || true)"
if [[ "$home_opts" == *nodev* ]]; then
    NEED_BIND=1
else
    NEED_BIND=0
fi

cleanup_artifacts() {
    echo "[build.sh] cleaning prior build artifacts in $WORKSPACE_ISO_DIR"
    sudo rm -rf \
        "$WORKSPACE_ISO_DIR/.build" \
        "$WORKSPACE_ISO_DIR/cache" \
        "$WORKSPACE_ISO_DIR/chroot" \
        "$WORKSPACE_ISO_DIR/binary"

    sudo rm -f \
        "$WORKSPACE_ISO_DIR"/live-image-* \
        "$WORKSPACE_ISO_DIR"/chroot.* \
        "$WORKSPACE_ISO_DIR"/binary.modified_timestamps \
        "$WORKSPACE_ISO_DIR"/build.log
}

stage_slice_bc_artifacts() {
    echo "[build.sh] staging artifacts via $BUILD_BINARIES_SCRIPT"

    if [[ ! -x "$BUILD_BINARIES_SCRIPT" ]]; then
        echo "[build.sh] ERROR: missing or non-executable $BUILD_BINARIES_SCRIPT" >&2
        exit 1
    fi

    "$BUILD_BINARIES_SCRIPT"
}

determine_build_version() {
    local latest_tag
    latest_tag="$(git -C "$REPO_ROOT" tag -l 'v*.*.*' | sort -V | tail -n 1 || true)"

    if [[ -z "$latest_tag" ]]; then
        latest_tag="v0.0.0"
        echo "[build.sh] warning: no semantic git tags found; defaulting to $latest_tag"
    fi

    local short_hash
    short_hash="$(git -C "$REPO_ROOT" rev-parse --short HEAD)"

    BUILD_VERSION_STRING="n-os-tr ${latest_tag} (${short_hash})"
}

stage_version_metadata() {
    determine_build_version

    local version_dir="$BUILD_DIR/config/includes.chroot/etc/n-os-tr"
    local version_file="$version_dir/version"
    local issue_file="$BUILD_DIR/config/includes.chroot/etc/issue"

    mkdir -p "$version_dir"
    printf '%s\n' "$BUILD_VERSION_STRING" > "$version_file"

    if [[ ! -f "$ISSUE_TEMPLATE_PATH" ]]; then
        echo "[build.sh] missing issue template: $ISSUE_TEMPLATE_PATH" >&2
        exit 1
    fi

    sed "s|__N_OS_TR_VERSION__|$BUILD_VERSION_STRING|g" "$ISSUE_TEMPLATE_PATH" > "$issue_file"

    echo "[build.sh] stamped version: $BUILD_VERSION_STRING"
    echo "[build.sh] wrote: $version_file"
    echo "[build.sh] rendered: $issue_file"
}

if [[ "$CLEAN_REQUESTED" -eq 1 ]]; then
    cleanup_artifacts
fi

SCRATCH=""
BUILD_DIR=""
CLEANUP() {
    if [[ -n "$SCRATCH" ]]; then
        if mountpoint -q "$SCRATCH"; then
            sudo umount -R "$SCRATCH" 2>/dev/null || sudo umount -l "$SCRATCH" || true
        fi
        rmdir "$SCRATCH" 2>/dev/null || true
    fi
}
trap CLEANUP EXIT

if [[ "$NEED_BIND" -eq 1 ]]; then
    echo "[build.sh] /home has nodev mount option; building via bind-mounted scratch workspace"
    SCRATCH="/var/tmp/n-os-tr-build-$$-$(date +%s)"
    mkdir -p "$SCRATCH"
    sudo mount --bind "$REPO_ROOT" "$SCRATCH"
    echo "[build.sh] remounting scratch bind with dev to allow chroot /dev/null usage"
    sudo mount -o remount,bind,dev "$SCRATCH"

    scratch_opts="$(findmnt -n -o OPTIONS "$SCRATCH" 2>/dev/null || true)"
    if [[ "$scratch_opts" == *nodev* ]]; then
        echo "[build.sh] ERROR: scratch bind still has nodev after remount: $scratch_opts" >&2
        echo "[build.sh] cannot safely run live-build chroot on a nodev mount" >&2
        exit 1
    fi

    BUILD_DIR="$SCRATCH/iso"
else
    echo "[build.sh] /home is not nodev; building directly in workspace"
    BUILD_DIR="$WORKSPACE_ISO_DIR"
fi

if [[ ! -d "$BUILD_DIR" ]]; then
    echo "[build.sh] build directory missing: $BUILD_DIR" >&2
    exit 1
fi

stage_version_metadata

if [[ "$ISO_ONLY" -eq 1 ]]; then
    echo "[build.sh] fast mode: skipping includes/ binary rebuild"
else
    stage_slice_bc_artifacts
fi

cd "$BUILD_DIR"

if [[ "$RECONFIGURE" -eq 1 || ! -f "$BUILD_DIR/config/bootstrap" ]]; then
    echo "[build.sh] running lb config"
    sudo "$REPO_ROOT/lb-wrapper.sh" config
else
    echo "[build.sh] skipping lb config (use --reconfigure to force)"
fi

if [[ "$OFFLINE" -eq 1 ]]; then
    echo "[build.sh] offline mode: network downloads disabled (use --online to allow)"
    sudo env http_proxy=http://127.0.0.1:9 https_proxy=http://127.0.0.1:9 ftp_proxy=http://127.0.0.1:9 no_proxy=localhost,127.0.0.1 "$REPO_ROOT/lb-wrapper.sh" build 2>&1 | tee "$BUILD_LOG"
else
    echo "[build.sh] online mode: network downloads allowed"
    sudo "$REPO_ROOT/lb-wrapper.sh" build 2>&1 | tee "$BUILD_LOG"
fi

if [[ ! -f "$WORKSPACE_ISO" ]]; then
    echo "[build.sh] build produced no ISO at $WORKSPACE_ISO; see $BUILD_LOG" >&2
    exit 1
fi

ls -lh "$WORKSPACE_ISO"