#!/bin/bash
# Unit tests for netinfra/dns-cluster-setup/sync-zones.sh [#469]
# Verifies reload-on-change behavior: Technitium restart fires only when
# rsync actually changed zone files, and never on clean syncs.
set -euo pipefail

PROJECT_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
SCRIPT="$PROJECT_ROOT/netinfra/dns-cluster-setup/sync-zones.sh"

failed=0

TMP="$(mktemp -d)"
trap 'rm -rf "$TMP"' EXIT
export LOG_FILE="$TMP/sync.log"

# Script must exist and source cleanly (main guarded for sourcing)
if [[ -f "$SCRIPT" ]] && (source "$SCRIPT"); then
    echo "✅ script exists + sources cleanly"
else
    echo "❌ script missing or fails to source: $SCRIPT"
    exit 1
fi
# shellcheck disable=SC1091
source "$SCRIPT"

# Fake command log: record invocations of rsync / reload / find
FAKE_BIN="$TMP/bin"
mkdir -p "$FAKE_BIN"
export PATH="$FAKE_BIN:$PATH"

make_rsync() {
    # $1 = exit code, $2 = "changed" or "clean" (stdout of rsync)
    cat > "$FAKE_BIN/rsync" <<EOF
#!/bin/bash
echo "$2"
exit $1
EOF
    chmod +x "$FAKE_BIN/rsync"
}

make_reload() {
    cat > "$FAKE_BIN/reload" <<'EOF'
#!/bin/bash
echo "reload-fired" >> "$RELOAD_LOG"
EOF
    chmod +x "$FAKE_BIN/reload"
}

RELOAD_LOG="$TMP/reload.log"
touch "$RELOAD_LOG"
export RELOAD_LOG

# find: minimal fake so zone counting works
mkdir -p "$FAKE_BIN/find-dir"
cat > "$FAKE_BIN/find" <<'EOF'
#!/bin/bash
# report 3 fake zone files regardless of args
for i in 1 2 3; do echo "/zones/zone$i"; done
EOF
chmod +x "$FAKE_BIN/find"

test_reload_fires_on_change() {
    make_rsync 0 "knel.net.zone"
    make_reload
    RELOAD_CMD=("$FAKE_BIN/reload")
    export RELOAD_CMD
    if sync_and_reload >/dev/null 2>&1 && [[ "$(cat "$RELOAD_LOG")" == "reload-fired" ]]; then
        echo "✅ reload fires when rsync reports changed zones"
    else
        echo "❌ reload did not fire on changed sync"
        ((++failed))
    fi
    : > "$RELOAD_LOG"
}

test_no_reload_on_clean_sync() {
    make_rsync 0 ""
    make_reload
    RELOAD_CMD=("$FAKE_BIN/reload")
    export RELOAD_CMD
    if sync_and_reload >/dev/null 2>&1 && [[ ! -s "$RELOAD_LOG" ]]; then
        echo "✅ no reload on clean sync"
    else
        echo "❌ reload fired (or errored) on clean sync"
        ((++failed))
    fi
}

test_rsync_failure_propagates() {
    make_rsync 23 ""
    RELOAD_CMD=("$FAKE_BIN/reload")
    export RELOAD_CMD
    if ! sync_and_reload >/dev/null 2>&1; then
        echo "✅ rsync failure propagates non-zero rc"
    else
        echo "❌ rsync failure was swallowed"
        ((++failed))
    fi
    if [[ ! -s "$RELOAD_LOG" ]]; then
        echo "✅ no reload attempted after rsync failure"
    else
        echo "❌ reload fired despite rsync failure"
        ((++failed))
    fi
}

test_reload_failure_does_not_break_sync() {
    make_rsync 0 "knel.net.zone"
    RELOAD_CMD=("/bin/false")
    export RELOAD_CMD
    if sync_and_reload >/dev/null 2>&1; then
        echo "✅ reload failure does not fail the sync run"
    else
        echo "❌ reload failure failed the whole sync"
        ((++failed))
    fi
}

test_reload_fires_on_change
test_no_reload_on_clean_sync
test_rsync_failure_propagates
test_reload_failure_does_not_break_sync

if ((failed > 0)); then
    echo "❌ $failed sync-zones test(s) failed"
    exit 1
fi
echo "✅ all sync-zones tests passed"