#!/usr/bin/env bash

set -Eeuo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/../../.." && pwd)"
DOWNLOAD_SCRIPT="$ROOT_DIR/scripts/download-geofabrik.sh"
TEST_ROOT="$(mktemp -d)"
FAKE_BIN="$TEST_ROOT/bin"
CALL_LOG="$TEST_ROOT/curl.log"
PBF_FIXTURE="$TEST_ROOT/snapshot.osm.pbf"
CHECKSUM_FIXTURE="$TEST_ROOT/snapshot.osm.pbf.md5"
trap 'rm -rf -- "$TEST_ROOT"' EXIT

mkdir -p "$FAKE_BIN"
printf 'verified geofabrik snapshot\n' >"$PBF_FIXTURE"

fail() {
  printf 'Fehler: %s\n' "$*" >&2
  exit 1
}

cat >"$FAKE_BIN/curl" <<'SH'
#!/usr/bin/env bash

set -Eeuo pipefail

is_head=false
output_path=""
url="${!#}"
for ((index = 1; index <= $#; index += 1)); do
  argument="${!index}"
  case "$argument" in
    --head)
      is_head=true
      ;;
    --output)
      index=$((index + 1))
      output_path="${!index}"
      ;;
  esac
done

if [[ "$is_head" == "true" ]]; then
  printf 'HEAD|%s\n' "$url" >>"$FAKE_CALL_LOG"
  printf '%s' "$FAKE_RESOLVED_URL"
  exit 0
fi

printf 'GET|%s\n' "$url" >>"$FAKE_CALL_LOG"
if [[ "$url" == "$FAKE_CHECKSUM_URL" ]]; then
  cp "$FAKE_CHECKSUM_FIXTURE" "$output_path"
  exit 0
fi
if [[ -n "${FAKE_PBF_URL:-}" && "$url" == "$FAKE_PBF_URL" ]]; then
  cp "$FAKE_PBF_FIXTURE" "$output_path"
  exit 0
fi

printf 'Unerwarteter Download: %s\n' "$url" >&2
exit 90
SH
chmod 0755 "$FAKE_BIN/curl"

snapshot_checksum="$(md5sum "$PBF_FIXTURE" | awk '{ print $1 }')"
printf '%s  germany-260728.osm.pbf\n' \
  "$snapshot_checksum" \
  >"$CHECKSUM_FIXTURE"

germany_output="$TEST_ROOT/germany"
germany_latest='https://download.example/europe/germany-latest.osm.pbf'
germany_mirror='https://mirror.example/geofabrik/germany-latest.osm.pbf'
PATH="$FAKE_BIN:$PATH" \
FAKE_CALL_LOG="$CALL_LOG" \
FAKE_RESOLVED_URL="$germany_mirror" \
FAKE_CHECKSUM_URL="$germany_mirror.md5" \
FAKE_CHECKSUM_FIXTURE="$CHECKSUM_FIXTURE" \
FAKE_PBF_URL="$germany_mirror" \
FAKE_PBF_FIXTURE="$PBF_FIXTURE" \
WATERMAPS_GEOFABRIK_DIR="$germany_output" \
WATERMAPS_GEOFABRIK_EUROPE_BASE_URL='https://download.example/europe' \
  "$DOWNLOAD_SCRIPT" germany

cmp --silent "$PBF_FIXTURE" "$germany_output/germany-latest.osm.pbf" ||
  fail "Der prüfsummengebundene Snapshot wurde nicht aktiviert."
grep -Fxq "GET|$germany_mirror.md5" "$CALL_LOG" ||
  fail "Die Prüfsumme wurde nicht vom effektiven Mirror gelesen."
grep -Fxq "GET|$germany_mirror" "$CALL_LOG" ||
  fail "Der PBF wurde nicht vom selben effektiven Mirror gelesen."
if grep -Fxq "GET|$germany_latest.md5" "$CALL_LOG"; then
  fail "Die potenziell veraltete Prüfsumme der ursprünglichen URL wurde verwendet."
fi

printf '%s  netherlands-260727.osm.pbf\n' \
  "$snapshot_checksum" \
  >"$CHECKSUM_FIXTURE"
: >"$CALL_LOG"
netherlands_output="$TEST_ROOT/netherlands"
mkdir -p "$netherlands_output"
printf 'previous valid snapshot\n' \
  >"$netherlands_output/netherlands-latest.osm.pbf"
netherlands_dated='https://mirror.example/geofabrik/netherlands-260728.osm.pbf'

set +e
PATH="$FAKE_BIN:$PATH" \
FAKE_CALL_LOG="$CALL_LOG" \
FAKE_RESOLVED_URL="$netherlands_dated" \
FAKE_CHECKSUM_URL="$netherlands_dated.md5" \
FAKE_CHECKSUM_FIXTURE="$CHECKSUM_FIXTURE" \
FAKE_PBF_URL='' \
FAKE_PBF_FIXTURE="$PBF_FIXTURE" \
WATERMAPS_GEOFABRIK_DIR="$netherlands_output" \
WATERMAPS_GEOFABRIK_EUROPE_BASE_URL='https://download.example/europe' \
  "$DOWNLOAD_SCRIPT" netherlands \
  >"$TEST_ROOT/mismatch.out" \
  2>&1
mismatch_status=$?
set -e

[[ "$mismatch_status" -ne 0 ]] ||
  fail "Eine Prüfsumme für einen anderen datierten Snapshot wurde akzeptiert."
grep -Fxq 'previous valid snapshot' \
  "$netherlands_output/netherlands-latest.osm.pbf" ||
  fail "Der bisherige Snapshot wurde nach einem Mismatch verändert."
if grep -Fxq "GET|$netherlands_dated" "$CALL_LOG"; then
  fail "Der PBF-Download begann trotz abweichendem Prüfsummendateinamen."
fi

printf 'Geofabrik-Download: Mirror-Bindung und datierter Mismatch: OK\n'