#!/bin/bash

# Function to display help
show_help() {
    echo "=== Usage: $0 <container_name> [config_path] ==="
    echo ""
    echo "Description:"
    echo "  Runs garbage collector in Docker registry container and restarts it"
    echo ""
    echo "Arguments:"
    echo "  <container_name>  - name or ID of Docker registry container (required)"
    echo "  [config_path]     - path to configuration file inside container (optional)"
    echo ""
    echo "If config path is not specified, script automatically searches in:"
    echo "  - /etc/docker/registry/config.yml"
    echo "  - /etc/distribution/config.yml"
    echo ""
    echo "Examples:"
    echo "  $0 registry"
    echo "  $0 my-registry-container"
    echo "  $0 registry /etc/distribution/config.yml"
    echo "  $0 \$(docker ps -qf 'name=registry') /custom/path/config.yml"
}

# Function to find configuration file
find_config() {
    local container="$1"
    local config_paths=(
        "/etc/docker/registry/config.yml"
        "/etc/distribution/config.yml"
    )

    # Add custom path if specified
    if [ -n "$2" ]; then
        config_paths=("$2" "${config_paths[@]}")
    fi

    echo "[Search] Looking for configuration file in container..."

    for path in "${config_paths[@]}"; do
        if docker exec "$container" test -f "$path" 2>/dev/null; then
            echo "  [OK] Configuration file found: ${path}"
            CONFIG_PATH="$path"
            return 0
        else
            echo "  [-] Not found: ${path}"
        fi
    done

    return 1
}

# Function to find all possible configs
find_all_configs() {
    local container="$1"
    echo "[Search] Performing extended search for configuration files..."

    # Look for all .yml and .yaml files that could be registry configs
    local configs=$(docker exec "$container" find / -type f \( -name "config.yml" -o -name "config.yaml" \) 2>/dev/null | grep -E "(registry|distribution|docker)" | head -10)

    if [ -n "$configs" ]; then
        echo "  [OK] Possible configuration files found:"
        echo "$configs" | nl -w2 -s') '

        # If exactly one file is found, offer it
        local count=$(echo "$configs" | wc -l)
        if [ "$count" -eq 1 ]; then
            echo "[Question] Configuration file found. Use it?"
            read -p "Use $(echo "$configs" | tr -d '\n')? (y/n) " -n 1 -r
            echo
            if [[ $REPLY =~ ^[Yy]$ ]]; then
                CONFIG_PATH=$(echo "$configs" | head -1)
                return 0
            fi
        fi

        # If multiple files or user refused
        echo "[Input] Please specify the path to the configuration file manually:"
        read -p "Path to config: " user_path
        if [ -n "$user_path" ]; then
            if docker exec "$container" test -f "$user_path" 2>/dev/null; then
                CONFIG_PATH="$user_path"
                return 0
            else
                echo "  [ERR] File not found: ${user_path}"
            fi
        fi
    fi

    return 1
}

# Colors for output
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m' # No Color

# Check for the first argument
if [ -z "$1" ]; then
    echo -e "${RED}[ERR] Error: container name not specified${NC}"
    echo ""
    show_help
    exit 1
fi

CONTAINER_NAME="$1"
CONFIG_PATH=""  # Will be determined later

# Check if container exists (in any state)
if ! docker ps -a --format '{{.Names}}' | grep -q "^${CONTAINER_NAME}$"; then
    echo -e "${RED}[ERR] Error: container '${CONTAINER_NAME}' not found${NC}"
    echo ""
    echo -e "${YELLOW}[List] Available containers:${NC}"
    docker ps -a --format "table {{.Names}}\t{{.Status}}\t{{.Image}}" | head -10
    echo ""
    show_help
    exit 1
fi

# Check if container is running
CONTAINER_STATUS=$(docker inspect --format='{{.State.Status}}' "$CONTAINER_NAME" 2>/dev/null)

if [ "$CONTAINER_STATUS" != "running" ]; then
    echo -e "${RED}[ERR] Error: container '${CONTAINER_NAME}' not running${NC}"
    echo -e "${YELLOW}[Status] Current status: ${CONTAINER_STATUS}${NC}"
    echo ""
    echo -e "${BLUE}[Hint] You can start the container with the command:${NC}"
    echo "  docker start $CONTAINER_NAME"
    exit 1
fi

# Determine path to configuration file
if [ -n "$2" ]; then
    # If path is specified explicitly, check it
    echo "[Search] Checking specified path: ${2}"
    if docker exec "$CONTAINER_NAME" test -f "$2" 2>/dev/null; then
        CONFIG_PATH="$2"
        echo "  [OK] Configuration file found"
    else
        echo -e "${RED}  [ERR] Specified file not found: ${2}${NC}"
        echo -e "${YELLOW}[Warning] Trying to find automatically...${NC}"
    fi
fi

# If path is not determined, try to find automatically
if [ -z "$CONFIG_PATH" ]; then
    if ! find_config "$CONTAINER_NAME" "$2"; then
        echo -e "${YELLOW}[Warning] Could not find configuration file in standard paths${NC}"

        # Offer extended search
        read -p "[Search] Perform extended search for configuration files? (y/n) " -n 1 -r
        echo
        if [[ $REPLY =~ ^[Yy]$ ]]; then
            if ! find_all_configs "$CONTAINER_NAME"; then
                echo -e "${RED}[ERR] Error: Could not find configuration file${NC}"
                exit 1
            fi
        else
            echo -e "${RED}[ERR] Operation canceled${NC}"
            exit 1
        fi
    fi
fi

echo -e "${GREEN}[OK] All checks passed${NC}"
echo "[Info] Using config: ${CONFIG_PATH}"
echo "[Start] Running garbage collector in container '${CONTAINER_NAME}'..."

# Execute garbage collector
if docker exec "$CONTAINER_NAME" registry garbage-collect "$CONFIG_PATH"; then
    echo -e "${GREEN}[OK] Garbage collector executed successfully${NC}"
else
    echo -e "${RED}[ERR] Error executing garbage collector${NC}"
    echo -e "${YELLOW}[Possible causes]:${NC}"
    echo "  - Insufficient permissions in container"
    echo "  - Incorrect path to configuration file"
    echo "  - Registry issues"
    exit 1
fi

# Restart container
echo "[Restart] Restarting container..."
if docker restart "$CONTAINER_NAME"; then
    echo -e "${GREEN}[OK] Container successfully restarted${NC}"
else
    echo -e "${RED}[ERR] Error restarting container${NC}"
    exit 1
fi

echo -e "${GREEN}[OK] DONE! Garbage collector completed, container restarted${NC}"

# Show container status
echo "[Status] Current container status:"
docker ps --filter "name=$CONTAINER_NAME" --format "table {{.Names}}\t{{.Status}}\t{{.RunningFor}}" | tail -n +2

# Show configuration file used
echo "[Info] Configuration file used: ${CONFIG_PATH}"