#!/bin/bash

# =============================================================================
# UV Migration Script (Robust Version)
# =============================================================================
# Migrates from pip/venv to uv package manager
# Enhanced error handling for production environments
# =============================================================================

# Don't exit on errors - handle them gracefully
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

# Script version
VERSION="1.1.0-robust"

# Print header
echo -e "${BLUE}=================================${NC}"
echo -e "${BLUE}   UV Migration Script v${VERSION}${NC}"
echo -e "${BLUE}=================================${NC}"
echo ""

# Function to print colored output
print_success() {
    echo -e "${GREEN}✅ $1${NC}"
}

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

print_error() {
    echo -e "${RED}❌ $1${NC}"
}

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

# Function to check if command exists
command_exists() {
    command -v "$1" >/dev/null 2>&1
}

# Function to get file size in human readable format
get_size() {
    if [[ "$OSTYPE" == "darwin"* ]]; then
        # macOS
        du -h "$1" 2>/dev/null | cut -f1 || echo "0B"
    else
        # Linux
        du -sh "$1" 2>/dev/null | cut -f1 || echo "0B"
    fi
}

# Check if we're in the project root
if [[ ! -f "pyproject.toml" && ! -f "requirements.txt" ]]; then
    print_error "Neither pyproject.toml nor requirements.txt found. Please run this script from the project root."
    exit 1
fi

print_info "Starting migration process..."
echo ""

# =============================================================================
# Step 1: Pre-migration Analysis
# =============================================================================
echo -e "${BLUE}📊 Pre-migration Analysis${NC}"
echo "----------------------------"

# Count cache files before cleanup (with timeout to prevent hanging)
print_info "Analyzing project files (this may take a moment)..."
PYCACHE_DIRS=$(timeout 30 find . -path "./.venv" -prune -o -path "./venv" -prune -o -name "__pycache__" -type d -print 2>/dev/null | wc -l | tr -d ' ')
PYC_FILES=$(timeout 30 find . -path "./.venv" -prune -o -path "./venv" -prune -o -name "*.pyc" -type f -print 2>/dev/null | wc -l | tr -d ' ')

echo "📁 Cache directories found: $PYCACHE_DIRS"
echo "📄 .pyc files found: $PYC_FILES"

# Check if pytest cache exists
if [[ -d ".pytest_cache" ]]; then
    PYTEST_SIZE=$(get_size ".pytest_cache")
    echo "🧪 Pytest cache size: $PYTEST_SIZE"
else
    echo "🧪 No pytest cache found"
fi

# Check for old venv
if [[ -d "venv" ]]; then
    print_warning "Old 'venv' directory still exists!"
    VENV_SIZE=$(get_size "venv")
    echo "📦 Old venv size: $VENV_SIZE"
else
    print_success "No old 'venv' directory found"
fi

# Check for requirements.txt
if [[ -f "requirements.txt" ]]; then
    print_warning "requirements.txt still exists (should be removed after migration)"
else
    print_success "requirements.txt already removed"
fi

echo ""

# =============================================================================
# Step 2: UV Installation Check
# =============================================================================
echo -e "${BLUE}🔧 UV Installation Check${NC}"
echo "----------------------------"

# Add UV to PATH if it exists
export PATH="$HOME/.local/bin:$PATH"

if command_exists uv; then
    UV_VERSION=$(uv --version 2>/dev/null | head -1)
    print_success "UV installed: $UV_VERSION"
else
    print_error "UV not found! Installing UV..."
    if command_exists curl; then
        curl -LsSf https://astral.sh/uv/install.sh | sh
        # Add to PATH for this session
        export PATH="$HOME/.local/bin:$PATH"
        if command_exists uv; then
            UV_VERSION=$(uv --version 2>/dev/null | head -1)
            print_success "UV installed successfully: $UV_VERSION"
        else
            print_error "UV installation failed!"
            exit 1
        fi
    else
        print_error "curl not found! Please install UV manually."
        exit 1
    fi
fi

echo ""

# =============================================================================
# Step 3: Cache Cleanup (Robust Version)
# =============================================================================
echo -e "${BLUE}🧹 Cache Cleanup${NC}"
echo "-------------------"

# Ask for confirmation unless --force flag is provided
if [[ "$1" != "--force" ]]; then
    echo "This will delete:"
    echo "  - $PYCACHE_DIRS __pycache__ directories"
    echo "  - $PYC_FILES .pyc files"
    echo "  - .pytest_cache directory (if exists)"
    echo ""
    read -p "Continue with cleanup? (y/N): " -n 1 -r
    echo
    if [[ ! $REPLY =~ ^[Yy]$ ]]; then
        print_warning "Cleanup cancelled by user"
        exit 0
    fi
fi

print_info "Starting cleanup (using robust method for large file counts)..."

# Method 1: Use xargs for better handling of large file lists
DELETED_DIRS=0
DELETED_FILES=0

# Clean __pycache__ directories in batches
print_info "Cleaning __pycache__ directories..."
if find . -path "./.venv" -prune -o -path "./venv" -prune -o -name "__pycache__" -type d -print0 2>/dev/null | xargs -0 -r rm -rf; then
    DELETED_DIRS=$(echo "$PYCACHE_DIRS")
    print_success "Cleaned $DELETED_DIRS cache directories"
else
    print_warning "Some cache directories could not be deleted (may be permission issues)"
fi

# Clean .pyc files in batches
print_info "Cleaning .pyc files..."
if find . -path "./.venv" -prune -o -path "./venv" -prune -o -name "*.pyc" -type f -print0 2>/dev/null | xargs -0 -r rm -f; then
    DELETED_FILES=$(echo "$PYC_FILES")
    print_success "Cleaned $DELETED_FILES .pyc files"
else
    print_warning "Some .pyc files could not be deleted"
fi

# Clean .pyo files
print_info "Cleaning .pyo files..."
find . -path "./.venv" -prune -o -path "./venv" -prune -o -name "*.pyo" -type f -print0 2>/dev/null | xargs -0 -r rm -f

# Remove pytest cache
if [[ -d ".pytest_cache" ]]; then
    if rm -rf ".pytest_cache" 2>/dev/null; then
        print_success "Removed .pytest_cache directory"
    else
        print_warning "Could not remove .pytest_cache directory"
    fi
fi

print_success "Cleanup phase completed!"

echo ""

# =============================================================================
# Step 4: UV Environment Setup
# =============================================================================
echo -e "${BLUE}🔍 UV Environment Setup${NC}"
echo "------------------------"

# Check if pyproject.toml exists
if [[ ! -f "pyproject.toml" ]]; then
    print_warning "No pyproject.toml found. Creating basic one..."
    cat > pyproject.toml << 'EOF'
[project]
name = "trading-bot"
version = "1.0.0"
requires-python = ">=3.8"
dependencies = []

[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"
EOF
    print_info "Created basic pyproject.toml - you may need to add your dependencies"
fi

# Create/sync UV environment
print_info "Setting up UV environment..."
if uv sync; then
    print_success "UV environment ready"
else
    print_error "UV sync failed!"
    print_info "Trying alternative setup..."
    if uv venv && uv pip install -r requirements.txt 2>/dev/null; then
        print_success "UV environment created with fallback method"
    else
        print_error "Could not create UV environment"
        exit 1
    fi
fi

# Test imports
print_info "Testing environment..."
if uv run python -c "print('UV environment working!')" 2>/dev/null; then
    print_success "UV environment functional"
else
    print_warning "UV environment may have issues"
fi

echo ""

# =============================================================================
# Step 5: Old Files Cleanup (Optional)
# =============================================================================
echo -e "${BLUE}🗑️  Old Files Cleanup${NC}"
echo "-----------------------"

# Check for old venv directory
if [[ -d "venv" ]]; then
    VENV_SIZE=$(get_size "venv")
    print_warning "Old 'venv' directory found (${VENV_SIZE})"
    
    if [[ "$1" != "--force" ]]; then
        read -p "Delete old 'venv' directory? (y/N): " -n 1 -r
        echo
        if [[ $REPLY =~ ^[Yy]$ ]]; then
            if rm -rf "venv" 2>/dev/null; then
                print_success "Removed old 'venv' directory"
            else
                print_warning "Could not remove old 'venv' directory (check permissions)"
            fi
        else
            print_warning "Keeping old 'venv' directory"
        fi
    else
        if rm -rf "venv" 2>/dev/null; then
            print_success "Removed old 'venv' directory"
        else
            print_warning "Could not remove old 'venv' directory"
        fi
    fi
else
    print_success "No old 'venv' directory found"
fi

echo ""

# =============================================================================
# Final Summary
# =============================================================================
echo -e "${GREEN}🎉 Migration Summary${NC}"
echo "====================="
echo ""
print_success "UV migration completed!"
echo ""
echo "📋 What was done:"
echo "  ✅ Cleaned up cache files and directories"
echo "  ✅ Installed UV package manager"
echo "  ✅ Set up UV environment"
echo ""
echo "🚀 Next steps:"
echo "  • Test: uv run python --version"
echo "  • Run bot: uv run python trading_bot.py"
echo "  • Add packages: uv add package_name"
echo ""
echo "🔧 UV Quick Commands:"
echo "  uv sync                    # Sync dependencies"
echo "  uv add requests            # Add package"
echo "  uv run python script.py   # Run with UV"
echo ""
print_success "Migration complete! 🚀"