#!/bin/bash
# Ruby Version Manager (rbenv) Setup Script
# Installs rbenv and Ruby 3.1+ for CocoaPods compatibility

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

log_info() {
    echo -e "${GREEN}[INFO]${NC} $1"
}

log_warn() {
    echo -e "${YELLOW}[WARN]${NC} $1"
}

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

log_step() {
    echo -e "${BLUE}[STEP]${NC} $1"
}

# Check if rbenv is already installed
if command -v rbenv &> /dev/null; then
    log_info "rbenv is already installed"
    RBENV_INSTALLED=true
else
    log_step "Installing rbenv..."
    RBENV_INSTALLED=false
fi

# Install rbenv via Homebrew (recommended on macOS)
if [ "$RBENV_INSTALLED" = false ]; then
    if command -v brew &> /dev/null; then
        log_info "Installing rbenv via Homebrew..."
        brew install rbenv ruby-build
        
        # Initialize rbenv in shell
        if [ -n "$ZSH_VERSION" ]; then
            SHELL_CONFIG="$HOME/.zshrc"
        else
            SHELL_CONFIG="$HOME/.bash_profile"
        fi
        
        # Add rbenv initialization to shell config
        if ! grep -q "rbenv init" "$SHELL_CONFIG" 2>/dev/null; then
            log_info "Adding rbenv initialization to $SHELL_CONFIG..."
            echo '' >> "$SHELL_CONFIG"
            echo '# rbenv initialization' >> "$SHELL_CONFIG"
            echo 'eval "$(rbenv init - zsh)"' >> "$SHELL_CONFIG"
        fi
        
        # Load rbenv in current session
        eval "$(rbenv init - zsh)"
        
        log_info "✓ rbenv installed successfully"
    else
        log_warn "Homebrew not found. Installing rbenv manually..."
        
        # Manual installation via git
        if [ ! -d "$HOME/.rbenv" ]; then
            git clone https://github.com/rbenv/rbenv.git ~/.rbenv
        fi
        
        if [ ! -d "$HOME/.rbenv/plugins/ruby-build" ]; then
            mkdir -p ~/.rbenv/plugins
            git clone https://github.com/rbenv/ruby-build.git ~/.rbenv/plugins/ruby-build
        fi
        
        # Add to PATH
        export PATH="$HOME/.rbenv/bin:$PATH"
        eval "$(rbenv init - zsh)"
        
        # Add to shell config
        if [ -n "$ZSH_VERSION" ]; then
            SHELL_CONFIG="$HOME/.zshrc"
        else
            SHELL_CONFIG="$HOME/.bash_profile"
        fi
        
        if ! grep -q "rbenv init" "$SHELL_CONFIG" 2>/dev/null; then
            echo '' >> "$SHELL_CONFIG"
            echo '# rbenv initialization' >> "$SHELL_CONFIG"
            echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> "$SHELL_CONFIG"
            echo 'eval "$(rbenv init - zsh)"' >> "$SHELL_CONFIG"
        fi
        
        log_info "✓ rbenv installed manually"
    fi
fi

# Reload shell config
log_step "Reloading shell configuration..."
if [ -n "$ZSH_VERSION" ]; then
    source ~/.zshrc 2>/dev/null || true
else
    source ~/.bash_profile 2>/dev/null || true
fi

# Ensure rbenv is in PATH
export PATH="$HOME/.rbenv/bin:$PATH"
eval "$(rbenv init - zsh)" 2>/dev/null || eval "$(rbenv init - bash)" 2>/dev/null || true

# Check current Ruby version
log_step "Checking current Ruby version..."
CURRENT_RUBY=$(ruby -v 2>/dev/null | cut -d' ' -f2 | cut -d. -f1,2) || CURRENT_RUBY="unknown"

if [ "$CURRENT_RUBY" != "unknown" ]; then
    RUBY_MAJOR=$(echo "$CURRENT_RUBY" | cut -d. -f1)
    RUBY_MINOR=$(echo "$CURRENT_RUBY" | cut -d. -f2)
    
    if [ "$RUBY_MAJOR" -ge 3 ] && [ "$RUBY_MINOR" -ge 1 ]; then
        log_info "✓ Ruby version $CURRENT_RUBY is already >= 3.1.0"
        log_info "You can proceed with CocoaPods installation"
        exit 0
    else
        log_warn "Current Ruby version: $CURRENT_RUBY (needs 3.1.0+)"
    fi
fi

# Check if rbenv has a suitable Ruby version already installed
log_step "Checking installed Ruby versions..."
if rbenv versions | grep -qE "3\.(1|2|3|4)\."; then
    INSTALLED_RUBY=$(rbenv versions | grep -E "3\.(1|2|3|4)\." | tail -1 | sed 's/^[[:space:]]*//' | cut -d' ' -f1)
    log_info "Found installed Ruby version: $INSTALLED_RUBY"
    
    # Set as global if not already set
    CURRENT_GLOBAL=$(rbenv global)
    if [ "$CURRENT_GLOBAL" != "$INSTALLED_RUBY" ]; then
        log_info "Setting $INSTALLED_RUBY as default..."
        rbenv global "$INSTALLED_RUBY"
        rbenv rehash
    fi
    
    # Verify it works
    export PATH="$HOME/.rbenv/bin:$PATH"
    eval "$(rbenv init - zsh)" 2>/dev/null || eval "$(rbenv init - bash)" 2>/dev/null || true
    
    if ruby -rpsych -e "true" 2>/dev/null; then
        VERIFIED_RUBY=$(ruby -v)
        log_info "✓ Ruby $VERIFIED_RUBY is working correctly"
        log_info ""
        log_info "Ruby setup complete!"
        log_info ""
        log_info "Next steps:"
        log_info "  1. Reload your shell: source ~/.zshrc"
        log_info "  2. Verify Ruby: ruby -v"
        log_info "  3. Install CocoaPods: gem install cocoapods"
        exit 0
    else
        log_warn "Installed Ruby $INSTALLED_RUBY found but psych extension not working"
        log_warn "May need to reinstall Ruby or install libyaml dependencies"
    fi
fi

# Check for libyaml dependency (required for psych extension)
log_step "Checking for libyaml dependency..."
LIBYAML_FOUND=false
if command -v brew &> /dev/null; then
    if brew list libyaml &> /dev/null; then
        LIBYAML_FOUND=true
        log_info "✓ libyaml found via Homebrew"
    else
        log_warn "libyaml not installed. Installing via Homebrew..."
        if brew install libyaml; then
            LIBYAML_FOUND=true
            log_info "✓ libyaml installed successfully"
        else
            log_error "Failed to install libyaml via Homebrew"
        fi
    fi
else
    # Check if libyaml headers exist in system locations
    if find /usr/local /opt /Library -name "yaml.h" 2>/dev/null | grep -q yaml.h; then
        LIBYAML_FOUND=true
        log_info "✓ libyaml headers found in system"
    else
        log_warn "libyaml not found. Ruby installation may fail."
        log_warn "Install libyaml via Homebrew: brew install libyaml"
        log_warn "Or install via MacPorts: sudo port install libyaml"
    fi
fi

# List available Ruby versions
log_step "Fetching available Ruby versions..."
rbenv install --list | grep -E "^[[:space:]]*3\.[1-9]" | tail -5 || log_warn "Could not fetch Ruby versions list"

# Install Ruby 3.1.0 (preferred for compatibility)
log_step "Installing Ruby 3.1.0..."
if rbenv install 3.1.0; then
    log_info "✓ Ruby 3.1.0 installed successfully"
    
    # Set as global default
    log_step "Setting Ruby 3.1.0 as default..."
    rbenv global 3.1.0
    
    # Verify installation
    export PATH="$HOME/.rbenv/bin:$PATH"
    eval "$(rbenv init - zsh)" 2>/dev/null || eval "$(rbenv init - bash)" 2>/dev/null || true
    
    NEW_RUBY=$(ruby -v)
    log_info "✓ Current Ruby version: $NEW_RUBY"
    
    # Verify psych extension works
    if ruby -rpsych -e "true" 2>/dev/null; then
        log_info "✓ psych extension verified"
    else
        log_warn "psych extension may not be working correctly"
        log_warn "This may affect CocoaPods installation"
    fi
    
    # Rehash to make Ruby available
    rbenv rehash
    
    log_info ""
    log_info "Ruby setup complete!"
    log_info ""
    log_info "Next steps:"
    log_info "  1. Reload your shell: source ~/.zshrc"
    log_info "  2. Verify Ruby: ruby -v"
    log_info "  3. Install CocoaPods: gem install cocoapods"
    
else
    log_error "Failed to install Ruby 3.1.0"
    
    if [ "$LIBYAML_FOUND" = false ]; then
        log_error ""
        log_error "Installation failed. This is likely due to missing libyaml dependency."
        log_error ""
        log_error "To fix:"
        if command -v brew &> /dev/null; then
            log_error "  brew install libyaml"
        else
            log_error "  Install Homebrew: /bin/bash -c \"\$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)\""
            log_error "  Then: brew install libyaml"
        fi
        log_error ""
        log_error "After installing libyaml, run this script again."
    else
        log_error "Installation failed. Please check your internet connection and try again."
    fi
    exit 1
fi