#!/bin/bash
# validate-init-services.sh — Post-image init service validation
#
# Validates that init service files in a built image match expectations:
# 1. Config overrides in /etc/init.d/ differ from /usr/lib/init.d/ counterparts
# 2. No missing init service files that configs expected to create
# 3. Scheme-type services have corresponding binaries
# 4. No dependency cycles in service graph
#
# Requires: redoxfs FUSE mount (or ext4 mount)
#
# Usage:
#   scripts/validate-init-services.sh build/x86_64/redbear-full/harddrive.img
#   scripts/validate-init-services.sh build/x86_64/redbear-mini/harddrive.img
#
# Exit codes:
#   0 — All validations passed
#   1 — Validation failures found

set -euo pipefail

IMAGE_PATH="${1:?Usage: $0 <image-path>}"

if [ ! -f "$IMAGE_PATH" ]; then
    echo "ERROR: Image not found: $IMAGE_PATH" >&2
    exit 1
fi

MOUNT_DIR=$(mktemp -d /tmp/redbear-validate-XXXXXX)
failures=0

cleanup() {
    fusermount -u "$MOUNT_DIR" 2>/dev/null || true
    rmdir "$MOUNT_DIR" 2>/dev/null || true
}
trap cleanup EXIT

echo "=== Mounting image ==="
redoxfs "$IMAGE_PATH" "$MOUNT_DIR"
sleep 1

echo ""
echo "=== 1. Checking /etc/init.d/ override effectiveness ==="

if [ -d "$MOUNT_DIR/usr/lib/init.d" ] && [ -d "$MOUNT_DIR/etc/init.d" ]; then
    etc_count=$(find "$MOUNT_DIR/etc/init.d" -type f 2>/dev/null | wc -l)
    usr_count=$(find "$MOUNT_DIR/usr/lib/init.d" -type f 2>/dev/null | wc -l)
    echo "  /usr/lib/init.d/: $usr_count files"
    echo "  /etc/init.d/:     $etc_count files"

    for etc_file in "$MOUNT_DIR"/etc/init.d/*; do
        [ -f "$etc_file" ] || continue
        basename=$(basename "$etc_file")
        usr_file="$MOUNT_DIR/usr/lib/init.d/$basename"

        if [ -f "$usr_file" ]; then
            if diff -q "$etc_file" "$usr_file" > /dev/null 2>&1; then
                echo "  WARN: /etc/init.d/$basename identical to /usr/lib/init.d/$basename (redundant override)"
            else
                echo "  OK: /etc/init.d/$basename differs from /usr/lib/init.d/$basename (override active)"
            fi
        else
            echo "  OK: /etc/init.d/$basename (new service, no package counterpart)"
        fi
    done
else
    echo "  One or both init.d directories missing — skipping override check"
fi

echo ""
echo "=== 2. Checking scheme-type services have binaries ==="

if [ -d "$MOUNT_DIR/usr/lib/init.d" ] || [ -d "$MOUNT_DIR/etc/init.d" ]; then
    for svc_file in "$MOUNT_DIR"/usr/lib/init.d/*.service "$MOUNT_DIR"/etc/init.d/*.service; do
        [ -f "$svc_file" ] || continue

        scheme_name=$(grep -oP 'type\s*=\s*\{\s*scheme\s*=\s*"([^"]+)"' "$svc_file" 2>/dev/null | grep -oP '"[^"]+"' | tr -d '"' || true)
        if [ -n "$scheme_name" ]; then
            # Scheme daemon binaries use <name>d convention (e.g., scheme "evdev" -> binary "evdevd")
            found_binary=false
            for candidate in "$scheme_name" "${scheme_name}d" "redbear-$scheme_name"; do
                if [ -x "$MOUNT_DIR/usr/bin/$candidate" ]; then
                    echo "  OK: scheme '$scheme_name' has binary /usr/bin/$candidate"
                    found_binary=true
                    break
                fi
            done
            if [ "$found_binary" = "false" ]; then
                echo "  FAIL: scheme '$scheme_name' has NO binary at /usr/bin/$scheme_name, /usr/bin/${scheme_name}d, or /usr/bin/redbear-$scheme_name"
                failures=$((failures + 1))
            fi
        fi
    done
fi

echo ""
echo "=== 3. Checking service dependency graph for cycles ==="

if [ -d "$MOUNT_DIR/usr/lib/init.d" ] || [ -d "$MOUNT_DIR/etc/init.d" ]; then
    # Collect all services
    services_dir=$(mktemp -d)
    for svc_file in "$MOUNT_DIR"/usr/lib/init.d/* "$MOUNT_DIR"/etc/init.d/*; do
        [ -f "$svc_file" ] || continue
        basename=$(basename "$svc_file")
        cp "$svc_file" "$services_dir/$basename" 2>/dev/null || true
    done

    # Simple cycle detection: build adjacency list, do DFS
    python3 -c "
import os, re, sys
from collections import defaultdict

svc_dir = '$services_dir'
graph = defaultdict(list)
all_nodes = set()

for f in os.listdir(svc_dir):
    all_nodes.add(f)
    content = open(os.path.join(svc_dir, f)).read()
    for dep in re.findall(r'requires_weak\s*=\s*\[([^\]]*)\]', content) + re.findall(r'requires\s*=\s*\[([^\]]*)\]', content):
        for d in re.findall(r'\"([^\"]+)\"', dep):
            graph[f].append(d)

# DFS cycle detection
WHITE, GRAY, BLACK = 0, 1, 2
color = {n: WHITE for n in all_nodes}
has_cycle = False

def dfs(node):
    global has_cycle
    color[node] = GRAY
    for neighbor in graph.get(node, []):
        if neighbor not in color:
            continue
        if color[neighbor] == GRAY:
            print(f'  CYCLE: {node} -> {neighbor}')
            has_cycle = True
        elif color[neighbor] == WHITE:
            dfs(neighbor)
    color[node] = BLACK

for node in sorted(all_nodes):
    if color[node] == WHITE:
        dfs(node)

if not has_cycle:
    print('  OK: No dependency cycles detected')
else:
    sys.exit(1)
" 2>&1 || {
        echo "  FAIL: Dependency cycle detected!"
        failures=$((failures + 1))
    }

    rm -rf "$services_dir"
fi

echo ""
echo "=== 4. Checking for missing dependencies ==="

if [ -d "$MOUNT_DIR/usr/lib/init.d" ] || [ -d "$MOUNT_DIR/etc/init.d" ]; then
    all_files=$(mktemp)
    for svc_file in "$MOUNT_DIR"/usr/lib/init.d/* "$MOUNT_DIR"/etc/init.d/*; do
        [ -f "$svc_file" ] || continue
        basename "$svc_file" >> "$all_files"
    done

    for svc_file in "$MOUNT_DIR"/usr/lib/init.d/* "$MOUNT_DIR"/etc/init.d/*; do
        [ -f "$svc_file" ] || continue
        svc_name=$(basename "$svc_file")
        for dep in $(grep -oP 'requires_weak\s*=\s*\[([^\]]*)\]' "$svc_file" 2>/dev/null | grep -oP '"[^"]+"' | tr -d '"' || true); do
            if ! grep -q "^${dep}$" "$all_files" 2>/dev/null; then
                echo "  WARN: $svc_name requires '$dep' but file not found in any init.d directory"
            fi
        done
        for dep in $(grep -oP 'requires\s*=\s*\[([^\]]*)\]' "$svc_file" 2>/dev/null | grep -oP '"[^"]+"' | tr -d '"' || true); do
            if ! grep -q "^${dep}$" "$all_files" 2>/dev/null; then
                echo "  FAIL: $svc_name requires '$dep' (hard dep) but file not found"
                failures=$((failures + 1))
            fi
        done
    done
    rm -f "$all_files"
fi

echo ""
echo "=== Validation complete ==="
if [ $failures -gt 0 ]; then
    echo "FAILED: $failures validation failure(s) found" >&2
    exit 1
else
    echo "PASSED: All validations passed"
fi