#!/usr/bin/env bash
# publish-apk <apk> <published-name> [--host tungsten] [--dir /site/static.terst.org/public/files]
#
# Publishes a built APK to the static site, verifying every step that has gone wrong before:
# the host, that the file is really an APK, that what landed is byte-identical to what was
# tested, and that the web server actually serves it.
#
# Exists because publishing is where a silent mistake is most expensive. A stale published APK
# once sat for eight weeks while the repo moved on; installing it over current data threw
# "A migration from 11 to 6 was required but not found" and the app refused to start. The cost
# wasn't the bug, it was that nothing in the publish step had ever checked.
set -uo pipefail

die() { echo "publish-apk: $1" >&2; exit 2; }

EXPECT_HOST="tungsten"
DEST_DIR="/site/static.terst.org/public/files"

[ $# -ge 2 ] || die "usage: publish-apk <apk> <published-name> [--host H] [--dir D]"
APK="$1"; NAME="$2"; shift 2
while [ $# -gt 0 ]; do
    case "$1" in
        --host) EXPECT_HOST="$2"; shift 2 ;;
        --dir)  DEST_DIR="$2"; shift 2 ;;
        *) die "unknown option '$1'" ;;
    esac
done

case "$NAME" in
    */*) die "published name must be a bare filename, got '$NAME'" ;;
    *.apk) ;;
    *) die "published name should end in .apk, got '$NAME'" ;;
esac

# Publishing from a box that merely resembles the deploy host is how a previous session
# "deployed" to a sandbox and had to unwind it.
ACTUAL_HOST=$(hostname)
[ "$ACTUAL_HOST" = "$EXPECT_HOST" ] \
    || die "host is '$ACTUAL_HOST', expected '$EXPECT_HOST'. Build and test here, publish there."

[ -f "$APK" ] || die "no such file: $APK"
# An .apk is a zip; an HTML error page or a truncated copy is not.
head -c 2 "$APK" | grep -q "PK" || die "$APK is not a zip archive — not a real APK"
unzip -l "$APK" 2>/dev/null | grep -q "AndroidManifest.xml" \
    || die "$APK has no AndroidManifest.xml — not an APK"

[ -d "$DEST_DIR" ] || die "no such directory: $DEST_DIR"
DEST="$DEST_DIR/$NAME"

echo "=== publish-apk ==="
echo "host    : $ACTUAL_HOST"
echo "source  : $APK ($(stat -c%s "$APK") bytes)"
echo "dest    : $DEST"

if [ -f "$DEST" ]; then
    BACKUP="$DEST.$(date +%Y%m%d-%H%M%S).bak"
    cp "$DEST" "$BACKUP" || die "could not back up the existing file"
    echo "backup  : $BACKUP"
else
    echo "backup  : none needed (new file)"
fi

cp "$APK" "$DEST" || die "copy failed"
chmod 644 "$DEST" || die "chmod failed"
chown root:root "$DEST" 2>/dev/null || true

# The whole point: what is served must be what was tested.
if cmp -s "$APK" "$DEST"; then
    echo "identity: published copy is byte-identical to the source"
else
    die "published copy differs from the source — do not trust it"
fi

URL="https://static.terst.org/files/$NAME"
REMOTE_LEN=$(curl -sI "$URL" 2>/dev/null | tr -d '\r' | awk 'tolower($1)=="content-length:"{print $2}')
LOCAL_LEN=$(stat -c%s "$DEST")

if [ -z "$REMOTE_LEN" ]; then
    echo "serving : COULD NOT VERIFY (no content-length from $URL)"
    echo "result  : PARTIAL — the file is in place but the web server did not confirm it"
    exit 1
fi

echo "url     : $URL"
echo "serving : $REMOTE_LEN bytes"
if [ "$REMOTE_LEN" = "$LOCAL_LEN" ]; then
    echo "result  : PASS — served bytes match the tested build"
else
    echo "result  : FAIL — server reports $REMOTE_LEN, on disk $LOCAL_LEN"
    exit 1
fi