#!/bin/bash
# Environment Validation Script
# Checks if all prerequisites are installed and configured correctly

set -e

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

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

print_check() {
    if [ $1 -eq 0 ]; then
        echo -e "${GREEN}✓${NC} $2"
        return 0
    else
        echo -e "${RED}✗${NC} $2"
        return 1
    fi
}

print_warning() {
    echo -e "${YELLOW}⚠${NC} $1"
}

print_info() {
    echo -e "${BLUE}ℹ${NC} $1"
}

# Track overall status
ALL_CHECKS_PASSED=0

print_header "🔍 Validating Copilot SDK Development Environment"

# Check GitHub CLI
print_header "GitHub CLI"
if command -v gh &> /dev/null; then
    VERSION=$(gh --version | head -n1)
    print_check 0 "GitHub CLI installed: $VERSION"
    
    # Check authentication
    if gh auth status &> /dev/null; then
        print_check 0 "GitHub CLI is authenticated"
    else
        print_check 1 "GitHub CLI is not authenticated"
        print_info "Run: gh auth login"
        ALL_CHECKS_PASSED=1
    fi
else
    print_check 1 "GitHub CLI not found"
    print_info "Install from: https://cli.github.com/"
    ALL_CHECKS_PASSED=1
fi

# Check Copilot CLI
print_header "Copilot CLI"
if command -v copilot &> /dev/null; then
    print_check 0 "Copilot CLI is installed"
    
    # Try to get version
    if copilot --version &> /dev/null; then
        VERSION=$(copilot --version 2>&1 | head -n1 || echo "version check failed")
        print_info "Version: $VERSION"
    fi
else
    print_check 1 "Copilot CLI not found"
    print_info "Install: gh extension install github/gh-copilot"
    ALL_CHECKS_PASSED=1
fi

# Check Node.js
print_header "Node.js / TypeScript SDK"
if command -v node &> /dev/null; then
    NODE_VERSION=$(node -v)
    print_check 0 "Node.js installed: $NODE_VERSION"
    
    # Check version is 18+
    NODE_MAJOR=$(echo $NODE_VERSION | cut -d'v' -f2 | cut -d'.' -f1)
    if [ "$NODE_MAJOR" -ge 18 ]; then
        print_check 0 "Node.js version is 18+"
    else
        print_warning "Node.js version should be 18 or higher"
    fi
    
    if command -v npm &> /dev/null; then
        NPM_VERSION=$(npm -v)
        print_check 0 "npm installed: $NPM_VERSION"
    else
        print_check 1 "npm not found"
    fi
else
    print_warning "Node.js not installed (optional)"
    print_info "Install from: https://nodejs.org/"
fi

# Check Python
print_header "Python SDK"
if command -v python3 &> /dev/null; then
    PYTHON_VERSION=$(python3 --version)
    print_check 0 "Python installed: $PYTHON_VERSION"
    
    if command -v pip3 &> /dev/null; then
        PIP_VERSION=$(pip3 --version)
        print_check 0 "pip installed: $PIP_VERSION"
    else
        print_check 1 "pip not found"
    fi
    
    # Check for uv (recommended)
    if command -v uv &> /dev/null; then
        UV_VERSION=$(uv --version)
        print_check 0 "uv installed: $UV_VERSION (recommended)"
    else
        print_warning "uv not installed (recommended for faster package management)"
        print_info "Install: curl -LsSf https://astral.sh/uv/install.sh | sh"
    fi
else
    print_warning "Python not installed (optional)"
    print_info "Install from: https://www.python.org/"
fi

# Check Go
print_header "Go SDK"
if command -v go &> /dev/null; then
    GO_VERSION=$(go version)
    print_check 0 "Go installed: $GO_VERSION"
else
    print_warning "Go not installed (optional)"
    print_info "Install from: https://go.dev/doc/install"
fi

# Check .NET
print_header ".NET SDK"
if command -v dotnet &> /dev/null; then
    DOTNET_VERSION=$(dotnet --version)
    print_check 0 ".NET installed: $DOTNET_VERSION"
else
    print_warning ".NET not installed (optional)"
    print_info "Install from: https://dotnet.microsoft.com/download"
fi

# Check additional tools
print_header "Additional Tools"

if command -v git &> /dev/null; then
    GIT_VERSION=$(git --version)
    print_check 0 "Git installed: $GIT_VERSION"
else
    print_check 1 "Git not found (required)"
    ALL_CHECKS_PASSED=1
fi

if command -v code &> /dev/null; then
    print_check 0 "VS Code installed"
else
    print_warning "VS Code not installed (recommended)"
    print_info "Install from: https://code.visualstudio.com/"
fi

if command -v just &> /dev/null; then
    JUST_VERSION=$(just --version)
    print_check 0 "just command runner installed: $JUST_VERSION"
else
    print_warning "just not installed (optional, useful for running tasks)"
    print_info "Install from: https://github.com/casey/just"
fi

# Summary
print_header "Summary"

if [ $ALL_CHECKS_PASSED -eq 0 ]; then
    echo -e "${GREEN}✓ All required checks passed!${NC}"
    echo ""
    echo "Your environment is ready for Copilot SDK development!"
    echo ""
    echo "Next steps:"
    echo "1. Choose a template from: templates/"
    echo "2. Copy the template to start your project"
    echo "3. Follow the template's README for setup"
    echo ""
    echo "Quick start:"
    echo "  cd templates/typescript-quickstart  # or python-quickstart"
    echo "  npm install                         # or pip install -r requirements.txt"
    echo "  cp ../../.env.example .env"
    echo "  npm start                           # or python src/main.py"
    exit 0
else
    echo -e "${YELLOW}⚠ Some checks failed${NC}"
    echo ""
    echo "Please install the missing required components before continuing."
    echo "See the messages above for installation instructions."
    echo ""
    echo "Required:"
    echo "  - GitHub CLI (gh)"
    echo "  - Copilot CLI extension"
    echo "  - Git"
    echo ""
    echo "Optional (at least one SDK):"
    echo "  - Node.js (for TypeScript SDK)"
    echo "  - Python (for Python SDK)"
    echo "  - Go (for Go SDK)"
    echo "  - .NET (for .NET SDK)"
    exit 1
fi