check-requirements.sh

#!/bin/bash
# =============================================================================
# Requirements Verification Script for mflix Sample Application
# Python/FastAPI Backend
# =============================================================================
#
# This script checks that all necessary requirements are installed to run
# the mflix sample application with the Python/FastAPI backend.
#
# Usage:
#   ./check-requirements-python.sh           # Check all requirements (post-setup)
#   ./check-requirements-python.sh --pre     # Check only runtime requirements (pre-setup)
#   ./check-requirements-python.sh --setup   # Check and auto-setup missing items
#   ./check-requirements-python.sh --help    # Show help message
#
# =============================================================================

# Exit on error (but handle arithmetic expressions carefully)
set -e

# =============================================================================
# Configuration
# =============================================================================

SERVER_DIR="server"
CLIENT_DIR="client"
PYTHON_MIN_VERSION="3.11"
NODE_MIN_VERSION="18"

# =============================================================================
# Colors
# =============================================================================

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

# =============================================================================
# Counters
# =============================================================================

CHECKS_PASSED=0
CHECKS_FAILED=0
CHECKS_WARNED=0

# =============================================================================
# Helper Functions
# =============================================================================

print_header() {
    echo ""
    echo -e "${BLUE}━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━${NC}"
    echo -e "${BLUE}  $1${NC}"
    echo -e "${BLUE}━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━${NC}"
}

print_section() {
    echo ""
    echo -e "${YELLOW}▸ $1${NC}"
}

check_pass() {
    echo -e "  ${GREEN}✓${NC} $1"
    CHECKS_PASSED=$((CHECKS_PASSED + 1))
}

check_fail() {
    echo -e "  ${RED}✗${NC} $1"
    CHECKS_FAILED=$((CHECKS_FAILED + 1))
}

check_warn() {
    echo -e "  ${YELLOW}⚠${NC} $1"
    CHECKS_WARNED=$((CHECKS_WARNED + 1))
}

check_info() {
    echo -e "    ${BLUE}→${NC} $1"
}

command_exists() {
    command -v "$1" &>/dev/null
}

version_gte() {
    # Returns 0 (true) if $1 >= $2 using version sorting
    [ "$(printf '%s\n' "$2" "$1" | sort -V | head -n1)" = "$2" ]
}

show_help() {
    echo "Usage: $0 [OPTIONS]"
    echo ""
    echo "Options:"
    echo "  --pre      Check only runtime requirements (use before setup)"
    echo "  --setup    Attempt to automatically set up missing requirements"
    echo "  --help     Show this help message"
    echo ""
    echo "This script checks that all necessary requirements are installed"
    echo "to run the mflix sample application with the Python/FastAPI backend."
    echo ""
    echo "Use --pre before starting setup to verify you have the required runtime."
    echo "Use without flags after completing setup to verify everything is ready."
    exit 0
}

# =============================================================================
# Check Runtime Requirements (Pre-Setup)
# =============================================================================

check_runtime_requirements() {
    print_section "Runtime Requirements"

    # Check Python version
    if command_exists python3; then
        local python_version
        python_version=$(python3 --version 2>&1 | grep -oE '[0-9]+\.[0-9]+' | head -1)
        if version_gte "$python_version" "$PYTHON_MIN_VERSION"; then
            check_pass "Python $python_version installed (>= $PYTHON_MIN_VERSION required)"
        else
            check_fail "Python $python_version installed but >= $PYTHON_MIN_VERSION required"
            check_info "Install Python $PYTHON_MIN_VERSION+ from https://www.python.org/downloads/"
        fi
    else
        check_fail "Python 3 not installed"
        check_info "Install Python $PYTHON_MIN_VERSION+ from https://www.python.org/downloads/"
    fi

    # Check pip
    if command_exists pip3 || python3 -m pip --version &>/dev/null; then
        check_pass "pip installed"
    else
        check_fail "pip not installed"
        check_info "Install pip: python3 -m ensurepip --upgrade"
    fi
}

# =============================================================================
# Check Python/FastAPI Backend Requirements (Full)
# =============================================================================

check_backend_requirements() {
    print_section "Python/FastAPI Backend Requirements"

    local server_dir="$SCRIPT_DIR/$SERVER_DIR"

    # Check Python version
    if command_exists python3; then
        local python_version
        python_version=$(python3 --version 2>&1 | grep -oE '[0-9]+\.[0-9]+' | head -1)
        if version_gte "$python_version" "$PYTHON_MIN_VERSION"; then
            check_pass "Python $python_version installed (>= $PYTHON_MIN_VERSION required)"
        else
            check_fail "Python $python_version installed but >= $PYTHON_MIN_VERSION required"
            check_info "Install Python $PYTHON_MIN_VERSION+ from https://www.python.org/downloads/"
        fi
    else
        check_fail "Python 3 not installed"
        check_info "Install Python $PYTHON_MIN_VERSION+ from https://www.python.org/downloads/"
        return
    fi

    # Check pip
    if command_exists pip3 || python3 -m pip --version &>/dev/null; then
        check_pass "pip installed"
    else
        check_fail "pip not installed"
        check_info "Install pip: python3 -m ensurepip --upgrade"
    fi

    # Check virtual environment
    local venv_dir="$server_dir/.venv"
    if [[ -d "$venv_dir" ]]; then
        check_pass "Python virtual environment exists at $SERVER_DIR/.venv"

        # Check if venv activation script exists
        if [[ -f "$venv_dir/bin/activate" ]]; then
            check_pass "Virtual environment activation script exists"
        else
            check_warn "Virtual environment activation script missing"
        fi
    else
        check_warn "Python virtual environment not found at $SERVER_DIR/.venv"
        if [[ "$SETUP_MODE" == true ]]; then
            check_info "Creating virtual environment..."
            if python3 -m venv "$venv_dir"; then
                check_pass "Virtual environment created"
            else
                check_fail "Failed to create virtual environment"
            fi
        else
            check_info "Create with: cd $SERVER_DIR && python3 -m venv .venv"
        fi
    fi

    # Check Python dependencies
    local requirements_file="$server_dir/requirements.txt"
    if [[ -f "$requirements_file" ]]; then
        check_pass "requirements.txt found"

        # Check if key dependencies are installed
        if [[ -d "$venv_dir" ]]; then
            local pip_cmd="$venv_dir/bin/pip"
            if [[ -f "$pip_cmd" ]]; then
                # Check FastAPI
                if "$pip_cmd" show fastapi &>/dev/null; then
                    check_pass "FastAPI installed in virtual environment"
                else
                    check_warn "FastAPI not installed in virtual environment"
                    if [[ "$SETUP_MODE" == true ]]; then
                        check_info "Installing dependencies..."
                        if "$pip_cmd" install -r "$requirements_file" &>/dev/null; then
                            check_pass "Dependencies installed"
                        else
                            check_fail "Failed to install dependencies"
                        fi
                    else
                        check_info "Install with: source $SERVER_DIR/.venv/bin/activate && pip install -r $SERVER_DIR/requirements.txt"
                    fi
                fi

                # Check PyMongo
                if "$pip_cmd" show pymongo &>/dev/null; then
                    check_pass "PyMongo installed in virtual environment"
                else
                    check_warn "PyMongo not installed in virtual environment"
                fi
            fi
        fi
    else
        check_fail "requirements.txt not found at $SERVER_DIR/requirements.txt"
    fi
}

# =============================================================================
# Check Environment Configuration
# =============================================================================

check_env_configuration() {
    print_section "Environment Configuration"

    local server_dir="$SCRIPT_DIR/$SERVER_DIR"
    local env_file="$server_dir/.env"
    local env_example="$server_dir/.env.example"

    # Check .env file
    if [[ -f "$env_file" ]]; then
        check_pass ".env file exists"

        # Check MONGODB_URI
        if grep -q "^MONGODB_URI=" "$env_file" 2>/dev/null; then
            local mongo_uri
            mongo_uri=$(grep "^MONGODB_URI=" "$env_file" | cut -d'=' -f2-)
            if [[ -n "$mongo_uri" ]] && [[ "$mongo_uri" != *"<"*">"* ]]; then
                check_pass "MONGODB_URI is configured"
            else
                check_fail "MONGODB_URI is not configured (still has placeholder value)"
                check_info "Update MONGODB_URI in $SERVER_DIR/.env with your MongoDB connection string"
            fi
        else
            check_fail "MONGODB_URI not found in .env"
            check_info "Add MONGODB_URI to $SERVER_DIR/.env"
        fi

        # Check VOYAGE_API_KEY (optional)
        if grep -q "^VOYAGE_API_KEY=" "$env_file" 2>/dev/null; then
            local voyage_key
            voyage_key=$(grep "^VOYAGE_API_KEY=" "$env_file" | cut -d'=' -f2-)
            if [[ -n "$voyage_key" ]] && [[ "$voyage_key" != "your_voyage_api_key" ]]; then
                check_pass "VOYAGE_API_KEY is configured"
            else
                check_info "VOYAGE_API_KEY not configured (optional - needed for vector search)"
            fi
        else
            check_info "VOYAGE_API_KEY not set (optional - needed for vector search)"
        fi

        # Check CORS_ORIGINS (optional)
        if grep -q "^CORS_ORIGINS=" "$env_file" 2>/dev/null; then
            check_pass "CORS_ORIGINS is configured"
        else
            check_info "CORS_ORIGINS not set (will use default: http://localhost:3000)"
        fi

        # Check PORT (optional)
        if grep -q "^PORT=" "$env_file" 2>/dev/null; then
            check_pass "PORT is configured"
        else
            check_info "PORT not set (will use default: 3001)"
        fi
    else
        check_warn ".env file not found"
        if [[ -f "$env_example" ]]; then
            if [[ "$SETUP_MODE" == true ]]; then
                check_info "Creating .env from .env.example..."
                if cp "$env_example" "$env_file"; then
                    check_pass ".env file created from .env.example"
                    check_warn "Please update the placeholder values in $SERVER_DIR/.env"
                else
                    check_fail "Failed to create .env file"
                fi
            else
                check_info "Copy .env.example to .env: cp $SERVER_DIR/.env.example $SERVER_DIR/.env"
            fi
        else
            check_fail "No .env.example found to use as template"
        fi
    fi
}

# =============================================================================
# Check Frontend Requirements
# =============================================================================

check_frontend_requirements() {
    print_section "Frontend Requirements (Next.js)"

    local client_dir="$SCRIPT_DIR/$CLIENT_DIR"

    # Check Node.js
    if command_exists node; then
        local node_version
        node_version=$(node --version | sed 's/v//')
        local node_major
        node_major=$(echo "$node_version" | cut -d. -f1)
        if [[ "$node_major" -ge "$NODE_MIN_VERSION" ]]; then
            check_pass "Node.js installed (version $node_version, >= $NODE_MIN_VERSION required)"
        else
            check_fail "Node.js version $node_version is below minimum required ($NODE_MIN_VERSION+)"
            check_info "Install Node.js $NODE_MIN_VERSION+: https://nodejs.org/"
        fi
    else
        check_fail "Node.js not installed"
        check_info "Install Node.js $NODE_MIN_VERSION+: https://nodejs.org/"
        return
    fi

    # Check npm
    if command_exists npm; then
        local npm_version
        npm_version=$(npm --version)
        check_pass "npm installed (version $npm_version)"
    else
        check_fail "npm not installed"
        check_info "npm should come with Node.js installation"
        return
    fi

    # Check client directory
    if [[ ! -d "$client_dir" ]]; then
        check_warn "Client directory not found: $CLIENT_DIR"
        check_info "Frontend may be in a separate repository"
        return
    fi

    # Check client dependencies
    if [[ -d "$client_dir/node_modules" ]]; then
        check_pass "Frontend dependencies installed"

        # Check Next.js
        if [[ -d "$client_dir/node_modules/next" ]]; then
            check_pass "Next.js dependency installed"
        else
            check_warn "Next.js not found in dependencies"
        fi

        # Check React
        if [[ -d "$client_dir/node_modules/react" ]]; then
            check_pass "React dependency installed"
        else
            check_warn "React not found in dependencies"
        fi
    else
        check_warn "Frontend dependencies not installed"
        if [[ "$SETUP_MODE" == true ]]; then
            check_info "Installing frontend dependencies..."
            if (cd "$client_dir" && npm install &>/dev/null); then
                check_pass "Frontend dependencies installed successfully"
            else
                check_fail "Failed to install frontend dependencies"
            fi
        else
            check_info "Run: cd $CLIENT_DIR && npm install"
        fi
    fi
}

# =============================================================================
# Print Summary
# =============================================================================

print_summary() {
    print_header "Summary"
    echo ""
    echo -e "  ${GREEN}Passed:${NC}   $CHECKS_PASSED"
    echo -e "  ${RED}Failed:${NC}   $CHECKS_FAILED"
    echo -e "  ${YELLOW}Warnings:${NC} $CHECKS_WARNED"
    echo ""

    if [[ $CHECKS_FAILED -eq 0 ]]; then
        echo -e "${GREEN}All required checks passed!${NC}"
        if [[ $CHECKS_WARNED -gt 0 ]]; then
            echo -e "${YELLOW}There are some warnings to review.${NC}"
        fi
    else
        echo -e "${RED}Some checks failed. Please address the issues above.${NC}"
        if [[ "$SETUP_MODE" != true ]]; then
            echo -e "${BLUE}Tip: Run with --setup flag to auto-fix some issues${NC}"
        fi
    fi
    echo ""
}

# =============================================================================
# Main Execution
# =============================================================================

# Get script directory and change to it
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
cd "$SCRIPT_DIR"

# Default options
SETUP_MODE=false
PRE_CHECK_MODE=false

# Parse arguments
while [[ $# -gt 0 ]]; do
    case $1 in
        --pre)
            PRE_CHECK_MODE=true
            shift
            ;;
        --setup)
            SETUP_MODE=true
            shift
            ;;
        --help|-h)
            show_help
            ;;
        *)
            echo "Unknown option: $1"
            echo "Use --help for usage information"
            exit 1
            ;;
    esac
done

# Print banner
echo ""
echo -e "${BLUE}╔══════════════════════════════════════════════════════════════╗${NC}"
echo -e "${BLUE}║  mflix Sample Application - Requirements Check               ║${NC}"
echo -e "${BLUE}║  Python/FastAPI Backend                                      ║${NC}"
echo -e "${BLUE}╚══════════════════════════════════════════════════════════════╝${NC}"

if [[ "$PRE_CHECK_MODE" == true ]]; then
    echo -e "${YELLOW}Pre-setup check - verifying runtime requirements only${NC}"
elif [[ "$SETUP_MODE" == true ]]; then
    echo -e "${YELLOW}Running in setup mode - will attempt to fix issues${NC}"
fi

# Run checks based on mode
if [[ "$PRE_CHECK_MODE" == true ]]; then
    check_runtime_requirements
else
    check_backend_requirements
    check_env_configuration
    check_frontend_requirements
fi

# Print summary
print_summary

# Exit with appropriate code
if [[ $CHECKS_FAILED -gt 0 ]]; then
    exit 1
fi
exit 0