#!/bin/bash

# Gemini CLI Configuration Script for XCodeCLI
# This script configures Gemini CLI to use your XCodeCLI instance
# Automatically tests multiple API endpoints and selects the working one

set -e

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

# Configuration
DEFAULT_BASE_URL="https://api2.xcodecli.com"
GEMINI_CONFIG_DIR="$HOME/.gemini"
GEMINI_ENV_FILE="$GEMINI_CONFIG_DIR/.env"

# Function to print colored output
print_info() {
    echo -e "${BLUE}[INFO]${NC} $1"
}

print_success() {
    echo -e "${GREEN}[SUCCESS]${NC} $1"
}

print_warning() {
    echo -e "${YELLOW}[WARNING]${NC} $1"
}

print_error() {
    echo -e "${RED}[ERROR]${NC} $1"
}

# Function to backup existing settings
backup_settings() {
    if [ -f "$GEMINI_ENV_FILE" ]; then
        local backup_file="${GEMINI_ENV_FILE}.backup.$(date +%Y%m%d_%H%M%S)"
        cp "$GEMINI_ENV_FILE" "$backup_file"
        print_info "Backed up existing settings to: $backup_file"
    fi
    local settings_json_path="$GEMINI_CONFIG_DIR/settings.json"
    if [ -f "$settings_json_path" ]; then
        local backup_file="${settings_json_path}.backup.$(date +%Y%m%d_%H%M%S)"
        cp "$settings_json_path" "$backup_file"
        print_info "Backed up existing settings to: $backup_file"
    fi
}

# Function to create settings directory
create_settings_dir() {
    if [ ! -d "$GEMINI_CONFIG_DIR" ]; then
        mkdir -p "$GEMINI_CONFIG_DIR"
        print_info "Created Gemini configuration directory: $GEMINI_CONFIG_DIR"
    fi
}

# Function to validate API key format
validate_api_key() {
    local api_key="$1"
    if [[ ! "$api_key" =~ ^[A-Za-z0-9_-]+$ ]]; then
        print_error "Invalid API key format. API key should contain only alphanumeric characters, hyphens, and underscores."
        return 1
    fi
    return 0
}

# Function to test API connection and return working base URL
test_api_connection() {
    local api_key="$1"

    local test_urls=(
        "https://api2.xcodecli.com"
        "https://api.xcodecli.com"
    )

    print_info "Testing API connections..." >&2

    for base_url in "${test_urls[@]}"; do
        print_info "Testing $base_url..." >&2

        local test_endpoint="$base_url/v1/models"

        # Test with x-goog-api-key header (Gemini API style)
        local response
        response=$(curl -s -w "%{http_code}" -o /tmp/gemini_test_response \
            -X GET "$test_endpoint" \
            -H "Content-Type: application/json" \
            -H "x-goog-api-key: $api_key" \
            2>/dev/null || echo "000")

        if [ "$response" = "200" ]; then
            # Check if response contains models
            if grep -q '"models"' /tmp/gemini_test_response 2>/dev/null; then
                local model_count
                model_count=$(grep -oE '"name"[[:space:]]*:' /tmp/gemini_test_response | wc -l | tr -d ' ')
                print_success "API connection successful! Found $model_count models at $base_url" >&2
                rm -f /tmp/gemini_test_response
                echo "$base_url"
                return 0
            else
                print_warning "API responded but no models found at $base_url" >&2
            fi
        elif [ "$response" = "401" ]; then
            print_warning "API key authentication failed for $base_url" >&2
        elif [ "$response" = "000" ]; then
            print_warning "Cannot connect to $base_url" >&2
        else
            print_warning "API test failed for $base_url with HTTP status: $response" >&2
        fi

        rm -f /tmp/gemini_test_response
    done

    print_error "All API connections failed. Please check your API key and internet connection." >&2
    return 1
}

# Function to create Gemini CLI settings file
create_settings_file() {
    local base_url="$1"
    local api_key="$2"

    # Write to .env file
    cat <<EOF > "$GEMINI_ENV_FILE"
GOOGLE_GEMINI_BASE_URL="$base_url"
GEMINI_API_KEY="$api_key"
GEMINI_MODEL="gemini-3-pro-preview"
EOF
    print_success "Gemini CLI settings written to: $GEMINI_ENV_FILE"

    # Write to settings.json
    local settings_json_path="$GEMINI_CONFIG_DIR/settings.json"
    cat <<EOF > "$settings_json_path"
{
  "general": {
    "previewFeatures": true
  },
  "security": {
    "auth": {
      "selectedType": "gemini-api-key"
    }
  }
}
EOF
    print_success "Gemini CLI settings written to: $settings_json_path"
}

# Function to display current settings
display_settings() {
    if [ -f "$GEMINI_ENV_FILE" ]; then
        print_info "Current Gemini CLI settings file ($GEMINI_ENV_FILE):"
        echo "----------------------------------------"
        cat "$GEMINI_ENV_FILE"
        echo "----------------------------------------"
    else
        print_info "No existing Gemini CLI .env file found."
    fi
}

# Main function
main() {
    print_info "Gemini CLI Configuration Script for XCodeCLI"
    echo "======================================================="
    echo

    # Parse command line arguments
    local api_key=""
    local test_only=false
    local show_settings=false

    # Check for environment variable API_KEY
    if [ -n "$API_KEY" ]; then
        api_key="$API_KEY"
    fi

    while [[ $# -gt 0 ]]; do
        case $1 in
            -k|--key)
                api_key="$2"
                shift 2
                ;;
            -t|--test)
                test_only=true
                shift
                ;;
            -s|--show)
                show_settings=true
                shift
                ;;
            -h|--help)
                cat <<EOF
Usage: $0 [OPTIONS]

This script automatically tests multiple API endpoints and selects the working one:
  - https://api2.xcodecli.com
  - https://api.xcodecli.com

Options:
  -k, --key KEY     Set the API key
  -t, --test        Test API connections only (requires -k)
  -s, --show        Show current settings and exit
  -h, --help        Show this help message

Examples:
  $0 --key your-api-key-here
  $0 --test --key your-api-key-here
  $0 --show

Interactive mode (no arguments):
  $0

Environment Variables:
  API_KEY           API key for authentication
EOF
                exit 0
                ;;
            *)
                print_error "Unknown option: $1"
                print_info "Use --help for usage information"
                exit 1
                ;;
        esac
    done

    # Show settings and exit if requested
    if [ "$show_settings" = true ]; then
        display_settings
        exit 0
    fi

    # Interactive mode if no API key provided
    if [ -z "$api_key" ]; then
        print_info "Interactive setup mode"
        echo

        # Get API key
        while [ -z "$api_key" ]; do
            read -p "Enter your API key: " api_key
            if [ -z "$api_key" ]; then
                print_warning "API key is required"
            elif ! validate_api_key "$api_key"; then
                api_key=""
            fi
        done
    fi

    # Validate inputs
    if [ -z "$api_key" ]; then
        print_error "API key is required"
        print_info "Use --help for usage information"
        exit 1
    fi

    # Validate API key
    if ! validate_api_key "$api_key"; then
        exit 1
    fi

    print_info "API Key: ${api_key:0:8}...${api_key: -4}"
    echo

    # Test API connection and get working base URL
    local base_url
    base_url=$(test_api_connection "$api_key")

    if [ $? -ne 0 ] || [ -z "$base_url" ]; then
        if [ "$test_only" = true ]; then
            exit 1
        fi

        read -p "All API tests failed. Continue anyway? (y/N): " -n 1 -r
        echo
        if [[ ! $REPLY =~ ^[Yy]$ ]]; then
            print_info "Setup cancelled"
            exit 1
        fi

        # If user chooses to continue anyway, use default URL
        base_url="$DEFAULT_BASE_URL"
        print_warning "Using default URL: $base_url"
    else
        print_info "Selected working base URL: $base_url"
    fi

    # Exit if test only
    if [ "$test_only" = true ]; then
        print_success "API test completed successfully"
        exit 0
    fi

    # Create settings directory
    create_settings_dir

    # Backup existing settings
    backup_settings

    # Create new settings file
    create_settings_file "$base_url" "$api_key"

    echo
    print_success "Gemini CLI has been configured successfully!"
    print_info "You can now use Gemini CLI with your API router."
    print_info ""
    print_info "To verify the setup, run:"
    print_info "  gemini --version"
    print_info ""
    print_info "Configuration file location: $GEMINI_ENV_FILE"

    if [ -f "$GEMINI_ENV_FILE" ]; then
        echo
        print_info "Current settings:"
        cat "$GEMINI_ENV_FILE"
    fi
}

# Run main function
main "$@"