#!/system/bin/sh
# Driver Manager v2 - Driver Integrity Protection
# Monitor system drivers for unauthorized changes

MODDIR=${MODDIR:-/data/adb/modules/driver-manager}
. "$MODDIR/scripts/core.sh"
log_init "$LOGDIR/protect.log"

BASELINE="$CONFIGDIR/baseline.json"
REGISTRY="$CONFIGDIR/drivers.json"
BACKUPDIR="$MODDIR/backup"
CHANGELOG="$LOGDIR/changes.log"

# --- Create SHA256 baseline of all protected drivers ---
create_baseline() {
    log "Creating protection baseline"
    [ ! -f "$REGISTRY" ] && { echo '{"error": "No driver registry. Run scan first."}'; return 1; }

    local tmp="$CONFIGDIR/.baseline_tmp.json"
    echo '{"baseline":[' > "$tmp"
    local first=true

    # Extract protected driver paths from registry
    local in_driver=false protected=false path="" hash=""

    while IFS= read -r line; do
        case "$line" in
            *'"path"'*)
                path=$(echo "$line" | sed 's/.*: *"\([^"]*\)".*/\1/')
                ;;
            *'"protected"'*true*)
                protected=true
                ;;
            *'"protected"'*false*)
                protected=false
                ;;
            *\}*)
                if [ "$protected" = true ] && [ -n "$path" ] && [ -f "$path" ]; then
                    local cur_hash=$(sha256 "$path")
                    local sz=$(file_size "$path")
                    local ctx=$(get_selinux_context "$path")

                    [ "$first" = true ] && first=false || echo "," >> "$tmp"
                    cat >> "$tmp" << ENTRY
  {
    "path": "$path",
    "hash": "$cur_hash",
    "size": $sz,
    "selinux": "$ctx",
    "time": "$(date -Iseconds 2>/dev/null || date)"
  }
ENTRY

                    # Backup the file
                    local bkdir="$BACKUPDIR/$(dirname "$path" | sed 's|^/||')"
                    mkdir -p "$bkdir"
                    cp -p "$path" "$bkdir/" 2>/dev/null
                fi
                path="" protected=false
                ;;
        esac
    done < "$REGISTRY"

    echo "" >> "$tmp"
    echo '], "created": "'"$(date -Iseconds 2>/dev/null || date)"'"}' >> "$tmp"
    mv "$tmp" "$BASELINE"

    local count=$(grep -c '"path"' "$BASELINE" 2>/dev/null || echo 0)
    log "Baseline created: $count drivers protected"
    echo "{\"status\": \"ok\", \"protected_count\": $count}"
}

# --- Check all protected drivers against baseline ---
check_integrity() {
    [ ! -f "$BASELINE" ] && { echo '{"error": "No baseline. Run baseline first."}'; return 1; }

    log "Running integrity check"
    local changes=0 checked=0 ok=0
    local results='{"results":['
    local first=true

    local path="" expected_hash=""

    while IFS= read -r line; do
        case "$line" in
            *'"path"'*)
                path=$(echo "$line" | sed 's/.*: *"\([^"]*\)".*/\1/')
                ;;
            *'"hash"'*)
                expected_hash=$(echo "$line" | sed 's/.*: *"\([^"]*\)".*/\1/')
                ;;
            *\}*)
                if [ -n "$path" ] && [ -n "$expected_hash" ]; then
                    checked=$((checked + 1))
                    local status="ok"

                    if [ ! -f "$path" ]; then
                        status="missing"
                        changes=$((changes + 1))
                        echo "[$(date)] MISSING: $path" >> "$CHANGELOG"
                        log_error "Protected driver missing: $path"
                    else
                        local cur_hash=$(sha256 "$path")
                        if [ "$cur_hash" != "$expected_hash" ]; then
                            status="changed"
                            changes=$((changes + 1))
                            echo "[$(date)] CHANGED: $path (expected: $expected_hash, got: $cur_hash)" >> "$CHANGELOG"
                            log_error "Protected driver changed: $path"

                            # Auto-restore in enforce mode
                            local mode=$(get_setting "protection_mode")
                            if [ "$mode" = "enforce" ]; then
                                local backup="$BACKUPDIR/${path#/}"
                                if [ -f "$backup" ]; then
                                    cp -p "$backup" "$path" 2>/dev/null
                                    log "Auto-restored: $path"
                                    echo "[$(date)] RESTORED: $path" >> "$CHANGELOG"
                                    status="restored"
                                else
                                    log_error "Cannot restore $path: no backup"
                                fi
                            fi
                        else
                            ok=$((ok + 1))
                        fi
                    fi

                    [ "$first" = true ] && first=false || results="$results,"
                    results="$results{\"path\":\"$path\",\"status\":\"$status\"}"
                fi
                path="" expected_hash=""
                ;;
        esac
    done < "$BASELINE"

    results="$results],\"checked\":$checked,\"ok\":$ok,\"changes\":$changes,\"time\":\"$(date -Iseconds 2>/dev/null || date)\"}"
    log "Integrity check: $checked checked, $ok ok, $changes changes"
    echo "$results"
}

# --- Get protection status ---
get_status() {
    local mode=$(get_setting "protection_mode")
    local protected=0 last_check="never"

    [ -f "$BASELINE" ] && protected=$(grep -c '"path"' "$BASELINE" 2>/dev/null || echo 0)

    # Get last check time from changelog
    if [ -f "$CHANGELOG" ]; then
        last_check=$(tail -1 "$CHANGELOG" 2>/dev/null | grep -o '^\[[^]]*\]' | tr -d '[]')
    fi

    local watcher_running="false"
    is_running "protect" && watcher_running="true"

    echo "{\"mode\": \"$mode\", \"protected_count\": $protected, \"last_check\": \"$last_check\", \"watcher_running\": $watcher_running}"
}

# --- Set protection mode ---
set_mode() {
    local mode="$1"
    case "$mode" in
        off|monitor|enforce)
            json_set "$CONFIGDIR/settings.json" "protection_mode" "$mode"
            log "Protection mode set to: $mode"

            if [ "$mode" = "off" ]; then
                kill_by_pidfile "protect"
            fi

            echo "{\"status\": \"ok\", \"mode\": \"$mode\"}"
            ;;
        *)
            echo '{"error": "Invalid mode. Use: off, monitor, enforce"}'
            ;;
    esac
}

# --- Toggle protection for a specific driver ---
set_driver_protection() {
    local driver_id="$1"
    local protected="$2"

    if [ -f "$REGISTRY" ]; then
        if [ "$protected" = "true" ]; then
            sed -i "/$driver_id/,/protected/{s/\"protected\": false/\"protected\": true/}" "$REGISTRY"
        else
            sed -i "/$driver_id/,/protected/{s/\"protected\": true/\"protected\": false/}" "$REGISTRY"
        fi
        log "Driver $driver_id protection: $protected"
        echo "{\"status\": \"ok\", \"driver\": \"$driver_id\", \"protected\": $protected}"
    else
        echo '{"error": "No driver registry"}'
    fi
}

# --- Watch loop (runs as background daemon) ---
watch_loop() {
    log "Protection watcher started"
    while true; do
        local interval=$(get_setting_raw "protection_interval")
        [ -z "$interval" ] && interval=300

        sleep "$interval"

        local mode=$(get_setting "protection_mode")
        [ "$mode" = "off" ] && { log "Protection disabled, watcher exiting"; break; }

        check_integrity > /dev/null 2>&1
    done
}

# --- Get change log ---
get_changelog() {
    local lines="${2:-50}"
    if [ -f "$CHANGELOG" ]; then
        tail -n "$lines" "$CHANGELOG"
    else
        echo "No changes detected"
    fi
}

# --- Main ---
case "$1" in
    baseline)   create_baseline ;;
    check)      check_integrity ;;
    status)     get_status ;;
    mode)       set_mode "$2" ;;
    protect)    set_driver_protection "$2" "$3" ;;
    watch)      watch_loop ;;
    changelog)  get_changelog "$2" ;;
    *)          echo "Usage: protect.sh {baseline|check|status|mode|protect|watch|changelog} [args]" ;;
esac