#!/bin/bash
#
# stage-usb-share.sh - Put everything Build-PxeUsb.ps1 needs into a folder
# on a share, so a Windows PC can build the installer USB from it.
#
# Usage:
#   scripts/stage-usb-share.sh [--iso FILE] [--payload-root DIR] [DEST]
#
# DEST defaults to ~/pxe-images/pxe-usb (the [pxe-images] Samba share; on
# the work PC: \\<this PC>\pxe-images\pxe-usb, usually Z:\pxe-usb). It gets:
#   - the repo as committed (git archive HEAD: uncommitted edits are NOT
#     staged, so the stick matches a commit);
#   - the payload folders (offline-packages, pip-wheels, boot-files,
#     boot-tools, enrollment, bios-staging, drivers-staging, site-content)
#     as hard links, so they cost no extra disk space;
#   - the Ubuntu ISO offline-packages/ was built for (hard link);
#   - STAGED.txt: commit, date, sizes.
# Then on the work PC: copy the folder to a local disk (C:\pxe-usb) and
# double-click Build-PxeUsb.cmd (KB: docs/kb/How_To_Deploy_PXE_Server_New_Site.html).
#
# The new copy is built beside the old one and swapped in when complete.
# Run capture-site-content.sh --apply first so site-content/ is current.

set -euo pipefail

REPO_ROOT="$(cd "$(dirname "$0")"/.. && pwd)"
PAYLOAD_ROOT="$REPO_ROOT"
ISO=""
DEST=""

while [ $# -gt 0 ]; do
    case "$1" in
        --iso) ISO="${2:?}"; shift 2 ;;
        --payload-root) PAYLOAD_ROOT="$(cd "${2:?}" && pwd)"; shift 2 ;;
        -h|--help) sed -n '2,/^$/p' "$0" | sed 's/^# \{0,1\}//'; exit 0 ;;
        -*) echo "unknown option $1" >&2; exit 2 ;;
        *) DEST="$1"; shift ;;
    esac
done
DEST="${DEST:-$HOME/pxe-images/pxe-usb}"
mkdir -p "$(dirname "$DEST")"
DEST="$(cd "$(dirname "$DEST")" && pwd)/$(basename "$DEST")"

# Only ever replace a folder this script made (it is swapped and deleted).
if [ -e "$DEST" ] && [ ! -f "$DEST/STAGED.txt" ]; then
    echo "ERROR: $DEST exists and was not made by this script (no STAGED.txt); refusing to replace it" >&2
    exit 1
fi

# The ISO the offline set was resolved for (BUILD-INFO names it).
if [ -z "$ISO" ]; then
    name=$(sed -n 's/.*--iso \([^ ]*\.iso\).*/\1/p' "$PAYLOAD_ROOT/offline-packages/BUILD-INFO.txt" 2>/dev/null | head -1)
    name=$(basename "${name:-}")
    for d in "$PAYLOAD_ROOT" "$PAYLOAD_ROOT/iso" "${PXETEST_CACHE:-$HOME/.cache/pxetest}"; do
        [ -n "$name" ] && [ -f "$d/$name" ] && { ISO="$d/$name"; break; }
    done
    [ -n "$ISO" ] || { echo "ERROR: give --iso FILE (the offline set was built for ${name:-an unknown ISO})" >&2; exit 1; }
fi
[ -f "$ISO" ] || { echo "ERROR: ISO not found: $ISO" >&2; exit 1; }

same_fs() { [ "$(stat -c %d "$1")" = "$(stat -c %d "$2")" ]; }

NEW="$DEST.new.$$"
OLD="$DEST.old.$$"
cleanup() { [ -d "$NEW" ] && rm -rf -- "$NEW"; return 0; }
trap cleanup EXIT
mkdir -p "$NEW"

cd "$REPO_ROOT"
COMMIT=$(git rev-parse --short HEAD)
if ! git diff --quiet HEAD -- autoinstall playbook scripts webapp; then
    echo "NOTE: uncommitted changes in autoinstall/playbook/scripts/webapp are NOT staged (HEAD $COMMIT is)."
fi
echo "Repo $COMMIT -> $NEW"
git archive HEAD | tar -x -C "$NEW"

link_or_copy() {   # SRC DST
    if same_fs "$1" "$(dirname "$2")"; then cp -al "$1" "$2"; else cp -a "$1" "$2"; fi
}
for d in offline-packages pip-wheels boot-files boot-tools enrollment bios-staging drivers-staging site-content; do
    src="$PAYLOAD_ROOT/$d"
    [ -d "$src" ] || { echo "    $d: not in $PAYLOAD_ROOT (skipped)"; continue; }
    # git archive brings the tracked bits of boot-files/ and boot-tools/; the
    # payload folder replaces them whole.
    rm -rf -- "${NEW:?}/$d"
    link_or_copy "$src" "$NEW/$d"
    printf '    %-17s %s\n' "$d" "$(du -sh "$NEW/$d" | cut -f1)"
done
link_or_copy "$ISO" "$NEW/$(basename "$ISO")"
echo "    ISO               $(basename "$ISO")"

{
    echo "Staged by scripts/stage-usb-share.sh $(date -Is)"
    echo "Commit: $(git log -1 --format='%h %s')"
    echo "ISO: $(basename "$ISO")"
    echo "Payload root: $PAYLOAD_ROOT"
    echo
    echo "On the Windows PC:"
    echo "  1. Copy this whole folder to a local disk, e.g. C:\\pxe-usb"
    echo "  2. Double-click C:\\pxe-usb\\Build-PxeUsb.cmd (asks for admin, lists USB disks)"
    echo "  Instructions: docs\\kb\\How_To_Deploy_PXE_Server_New_Site.html"
} >"$NEW/STAGED.txt"

if [ -e "$DEST" ]; then mv -- "$DEST" "$OLD"; fi
mv -- "$NEW" "$DEST"
[ -e "$OLD" ] && rm -rf -- "$OLD"
trap - EXIT
echo "Staged: $DEST ($(du -sh "$DEST" | cut -f1) apparent, hard-linked payload)"