#!/usr/bin/env bash
# build_pack.sh - assemble ExilesPack-<YYYY.MM.DD>.zip (or ExilesPack-<tag>.zip with --tag)
#
# Reads manifest.yaml, fetches the latest release of every `include: true` repo
# from git.sub-net.at/Exiles, downloads the chosen zip asset(s), unpacks them
# into staging/, and rolls the combined result up into dist/ExilesPack-*.zip.
#
# We unpack the per-addon release zips (which contain just the addon folder,
# nothing else), so .git/.github/.gitea/README.md never enter the pack.
#
# Deps: bash, curl, jq, unzip, zip.   No yq needed - the manifest is parsed
# with a tiny awk pass tailored to its simple shape.

set -euo pipefail

# ---------------------------------------------------------------------------
# Paths + args
# ---------------------------------------------------------------------------
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
MANIFEST="$REPO_ROOT/manifest.yaml"
TMP_DIR="$REPO_ROOT/tmp"
STAGING_DIR="$REPO_ROOT/staging"
DIST_DIR="$REPO_ROOT/dist"

API="https://git.sub-net.at/api/v1"
ORG="Exiles"

TAG=""
while [ $# -gt 0 ]; do
  case "$1" in
    --tag) TAG="$2"; shift 2 ;;
    --tag=*) TAG="${1#--tag=}"; shift ;;
    -h|--help)
      cat <<USAGE
Usage: $0 [--tag <tag>]

Without --tag, the pack is named ExilesPack-<UTC YYYY.MM.DD>.zip.
With    --tag, the pack is named ExilesPack-<tag>.zip.
USAGE
      exit 0 ;;
    *) echo "unknown arg: $1" >&2; exit 2 ;;
  esac
done

if [ -z "$TAG" ]; then
  PACK_NAME="ExilesPack-$(date -u +%Y.%m.%d).zip"
else
  PACK_NAME="ExilesPack-${TAG}.zip"
fi

# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------
log()  { printf '[build_pack] %s\n' "$*"; }
warn() { printf '[build_pack] WARN: %s\n' "$*" >&2; }
die()  { printf '[build_pack] ERROR: %s\n' "$*" >&2; exit 1; }

# Parse manifest.yaml -> emit "<repo>" for every `include: true` entry.
# The manifest is a small fixed-shape YAML (no anchors, no nested lists), so a
# 20-line awk pass is more honest than pulling in a yq dependency.
manifest_includes() {
  awk '
    /^[[:space:]]*-[[:space:]]*repo:[[:space:]]*/ {
      sub(/^[[:space:]]*-[[:space:]]*repo:[[:space:]]*/, "")
      gsub(/[[:space:]]+$/, "")
      repo = $0
      include = ""
      next
    }
    /^[[:space:]]+include:[[:space:]]*/ {
      sub(/^[[:space:]]+include:[[:space:]]*/, "")
      gsub(/[[:space:]]+$/, "")
      include = $0
      if (repo != "" && include == "true") { print repo }
      repo = ""; include = ""
    }
  ' "$MANIFEST"
}

# Latest release JSON for a repo, or empty string if none.
latest_release_json() {
  local repo="$1" json
  json="$(curl -fsS "$API/repos/$ORG/$repo/releases?limit=1" 2>/dev/null || echo '[]')"
  # `releases?limit=1` returns an array. Strip the wrapper.
  if [ "$(printf '%s' "$json" | jq -r 'type')" = "array" ]; then
    printf '%s' "$json" | jq -c '.[0] // empty'
  else
    printf ''
  fi
}

# Download one URL with one retry. Stream to file.
fetch_with_retry() {
  local url="$1" out="$2"
  for attempt in 1 2; do
    if curl -fsSL --retry 0 -o "$out" "$url"; then
      return 0
    fi
    warn "download attempt $attempt failed for $url"
    sleep 2
  done
  return 1
}

# ---------------------------------------------------------------------------
# Reset workspace
# ---------------------------------------------------------------------------
rm -rf "$TMP_DIR" "$STAGING_DIR"
mkdir -p "$TMP_DIR" "$STAGING_DIR" "$DIST_DIR"

INCLUDED=0
SKIPPED=0
SKIPPED_REPOS=()

# ---------------------------------------------------------------------------
# Per-repo: pick assets, download, extract
# ---------------------------------------------------------------------------
while read -r repo; do
  [ -z "$repo" ] && continue
  log "processing $repo"

  rel="$(latest_release_json "$repo")"
  if [ -z "$rel" ] || [ "$rel" = "null" ]; then
    warn "$repo has no releases yet - skipping"
    SKIPPED=$((SKIPPED + 1))
    SKIPPED_REPOS+=("$repo")
    continue
  fi

  tag="$(printf '%s' "$rel" | jq -r '.tag_name')"
  log "  latest release: $tag"

  # Prefer <repo>-all.zip if present, otherwise take every *.zip asset.
  assets_all="$(printf '%s' "$rel" | jq -r --arg n "${repo}-all.zip" \
    '.assets[]? | select(.name == $n) | .browser_download_url')"
  if [ -n "$assets_all" ]; then
    download_urls="$assets_all"
    log "  using ${repo}-all.zip"
  else
    download_urls="$(printf '%s' "$rel" | jq -r \
      '.assets[]? | select(.name | endswith(".zip")) | .browser_download_url')"
  fi

  if [ -z "$download_urls" ]; then
    warn "$repo release $tag has no .zip assets - skipping"
    SKIPPED=$((SKIPPED + 1))
    SKIPPED_REPOS+=("$repo")
    continue
  fi

  mkdir -p "$TMP_DIR/$repo"
  any_ok=0
  while IFS= read -r url; do
    [ -z "$url" ] && continue
    name="$(basename "$url")"
    log "  downloading $name"
    if fetch_with_retry "$url" "$TMP_DIR/$repo/$name"; then
      if unzip -q -o "$TMP_DIR/$repo/$name" -d "$STAGING_DIR"; then
        any_ok=1
      else
        warn "  unzip failed for $name"
      fi
    else
      warn "  could not download $name after retry"
    fi
  done <<<"$download_urls"

  if [ "$any_ok" -eq 1 ]; then
    INCLUDED=$((INCLUDED + 1))
  else
    SKIPPED=$((SKIPPED + 1))
    SKIPPED_REPOS+=("$repo")
  fi
done < <(manifest_includes)

# ---------------------------------------------------------------------------
# Build the pack
# ---------------------------------------------------------------------------
if [ ! -d "$STAGING_DIR" ] || [ -z "$(ls -A "$STAGING_DIR" 2>/dev/null)" ]; then
  die "staging is empty - no addons were successfully fetched"
fi

OUT="$DIST_DIR/$PACK_NAME"
rm -f "$OUT"
( cd "$STAGING_DIR" && zip -qr "$OUT" . )

# ---------------------------------------------------------------------------
# Summary
# ---------------------------------------------------------------------------
ADDON_FOLDERS="$(cd "$STAGING_DIR" && find . -mindepth 1 -maxdepth 1 -type d | wc -l)"
SIZE="$(stat -c '%s' "$OUT")"
SHA="$(sha256sum "$OUT" | awk '{print $1}')"

echo
echo "============================================================"
echo " pack:        $PACK_NAME"
echo " path:        $OUT"
echo " addon dirs:  $ADDON_FOLDERS"
echo " size:        $SIZE bytes"
echo " sha256:      $SHA"
echo " repos in:    $INCLUDED"
echo " repos out:   $SKIPPED${SKIPPED_REPOS[*]:+ (${SKIPPED_REPOS[*]})}"
echo "============================================================"