#!/usr/bin/env bash
# download-leaflet.sh — Vendor Leaflet + leaflet.markercluster into static/leaflet/.
#
# The /photography/map/ page (build/Photography.hs photographyMapRules)
# loads Leaflet from /leaflet/ to render a map of geo-tagged photos.
# This vendoring keeps the page CDN-independent: the assets ship with
# the site, no third-party request at view time.
#
# Run once before deploying. The vendored copy is gitignored
# (~150 KB total); re-running is safe — files that already exist AND
# match their pinned checksum are skipped; anything missing or
# mismatched is re-fetched.
#
# To bump the pinned versions, set LEAFLET_VERSION / MARKERCLUSTER_VERSION,
# re-run, then update tools/leaflet-checksums.sha256 with the new hashes.

set -euo pipefail

REPO_ROOT="$(cd "$(dirname "$0")/.." && pwd)"
LEAFLET_DIR="$REPO_ROOT/static/leaflet"
CHECKSUMS="$REPO_ROOT/tools/leaflet-checksums.sha256"

LEAFLET_VERSION="${LEAFLET_VERSION:-1.9.4}"
MARKERCLUSTER_VERSION="${MARKERCLUSTER_VERSION:-1.5.3}"

UNPKG_LEAFLET="https://unpkg.com/leaflet@${LEAFLET_VERSION}/dist"
UNPKG_MC="https://unpkg.com/leaflet.markercluster@${MARKERCLUSTER_VERSION}/dist"

# Files to vendor: (URL_BASE LOCAL_PATH SOURCE_FILENAME PIN_KEY)
# PIN_KEY is the version-prefixed name in the checksum file so future
# version bumps don't accidentally accept files matching an older hash.
files_to_fetch=(
    "$UNPKG_LEAFLET|leaflet.js|leaflet-${LEAFLET_VERSION}-leaflet.js"
    "$UNPKG_LEAFLET|leaflet.css|leaflet-${LEAFLET_VERSION}-leaflet.css"
    "$UNPKG_LEAFLET/images|images/marker-icon.png|leaflet-${LEAFLET_VERSION}-marker-icon.png"
    "$UNPKG_LEAFLET/images|images/marker-icon-2x.png|leaflet-${LEAFLET_VERSION}-marker-icon-2x.png"
    "$UNPKG_LEAFLET/images|images/marker-shadow.png|leaflet-${LEAFLET_VERSION}-marker-shadow.png"
    "$UNPKG_MC|leaflet.markercluster.js|leaflet.markercluster-${MARKERCLUSTER_VERSION}-leaflet.markercluster.js"
    "$UNPKG_MC|MarkerCluster.css|leaflet.markercluster-${MARKERCLUSTER_VERSION}-MarkerCluster.css"
    "$UNPKG_MC|MarkerCluster.Default.css|leaflet.markercluster-${MARKERCLUSTER_VERSION}-MarkerCluster.Default.css"
)

mkdir -p "$LEAFLET_DIR/images"

verify_or_warn() {
    local file="$1"
    local pin_key="$2"
    if [ ! -f "$CHECKSUMS" ]; then
        echo "leaflet: $CHECKSUMS not found — skipping sha256 verification" >&2
        return 0
    fi
    local want
    want="$(awk -v p="$pin_key" '$2 == p { print $1; exit }' "$CHECKSUMS")"
    if [ -z "$want" ]; then
        echo "leaflet: no pinned checksum for $pin_key — skipping verification" >&2
        return 0
    fi
    local got
    got="$(sha256sum "$file" | awk '{ print $1 }')"
    if [ "$got" != "$want" ]; then
        echo "leaflet: sha256 mismatch for $pin_key" >&2
        echo "         expected $want" >&2
        echo "         got      $got" >&2
        return 1
    fi
}

# Per-file skip: existing files are skipped only after re-verifying
# their checksum, so a partial or tampered file from an interrupted
# earlier run can never be silently accepted. Downloads land in a
# .part temp and are only moved into place after verification — a
# failed verification leaves nothing at the final path.
for entry in "${files_to_fetch[@]}"; do
    IFS='|' read -r url_base local_path pin_key <<<"$entry"
    src_name="${local_path##*/}"
    target="$LEAFLET_DIR/$local_path"
    mkdir -p "$(dirname "$target")"

    if [ -f "$target" ]; then
        if verify_or_warn "$target" "$pin_key"; then
            echo "leaflet: $local_path present and verified (skipping)"
            continue
        fi
        echo "leaflet: $local_path failed verification — re-fetching" >&2
        rm -f "$target"
    fi

    echo "leaflet: fetching $local_path ($pin_key)"
    tmp="$target.part"
    curl -fsSL --progress-bar "$url_base/$src_name" -o "$tmp"
    if ! verify_or_warn "$tmp" "$pin_key"; then
        rm -f "$tmp"
        echo "leaflet: refusing to vendor unverified $local_path" >&2
        exit 1
    fi
    mv "$tmp" "$target"
done

echo "leaflet: vendored to $LEAFLET_DIR"