#!/bin/bash

# sync-env-to-launchctl
# Syncs environment variables from ~/.bash_profile to LaunchAgent

set -euo pipefail

# Configuration
PLIST_PATH="$HOME/Library/LaunchAgents/com.user.environment.plist"
BASH_PROFILE="$HOME/.bash_profile"
TEMP_DIR="/tmp/sync-env-$$"

# Variables to exclude from syncing
EXCLUDE_VARS=(
    "BASH_ARGC" "BASH_ARGV" "BASH_LINENO" "BASH_SOURCE"
    "DIRSTACK" "EUID" "GROUPS" "HOSTNAME" "PPID" "SECONDS"
    "SHELLOPTS" "SHLVL" "UID" "_" "COLUMNS" "LINES"
    "OLDPWD" "PWD" "SHELL" "TERM" "USER" "USERNAME"
    "HISTFILE" "HISTFILESIZE" "HISTSIZE" "HISTCONTROL"
    "PROMPT_COMMAND" 
    "PIPESTATUS" "FUNCNAME" "IFS" "LINENO" "RANDOM"
)

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

# Helper functions
log() { echo -e "${GREEN}[$(date +'%H:%M:%S')]${NC} $1"; }
warn() { echo -e "${YELLOW}[$(date +'%H:%M:%S')] WARNING:${NC} $1"; }
error() { echo -e "${RED}[$(date +'%H:%M:%S')] ERROR:${NC} $1" >&2; }

cleanup() {
    rm -rf "$TEMP_DIR"
}
trap cleanup EXIT

# Check if running in interactive mode (for debugging)
DRY_RUN=false
VERBOSE=false
while [[ $# -gt 0 ]]; do
    case $1 in
        --dry-run) DRY_RUN=true; shift ;;
        --verbose|-v) VERBOSE=true; shift ;;
        --help|-h)
            echo "Usage: $0 [--dry-run] [--verbose]"
            echo "  --dry-run   Show what would be done without making changes"
            echo "  --verbose   Show detailed output"
            exit 0
            ;;
        *) error "Unknown option: $1"; exit 1 ;;
    esac
done

# Create temp directory
mkdir -p "$TEMP_DIR"

# Function to check if variable should be excluded
should_exclude() {
    local var=$1
    for exclude in "${EXCLUDE_VARS[@]}"; do
        [[ "$var" == "$exclude" ]] && return 0
    done
    # Exclude functions and readonly variables
    [[ "$var" =~ ^[a-zA-Z_][a-zA-Z0-9_]*\(\)$ ]] && return 0
    return 1
}

# Get environment before sourcing
log "Capturing current environment..."
env | sort > "$TEMP_DIR/env_before.txt"

# Source bash profile in a subshell and get new environment
log "Sourcing $BASH_PROFILE..."
(
    set +e  # Don't exit on errors during sourcing
    source "$BASH_PROFILE" 2>/dev/null
    env | sort
) > "$TEMP_DIR/env_after.txt"

# Find new or changed environment variables
log "Detecting changes..."
comm -13 "$TEMP_DIR/env_before.txt" "$TEMP_DIR/env_after.txt" > "$TEMP_DIR/env_diff.txt"

# Process the differences
declare -A env_vars
while IFS='=' read -r key value; do
    # Skip if no = sign
    [[ ! "$key" =~ = ]] || continue
    
    # Skip excluded variables
    should_exclude "$key" && continue
    
    # Skip empty keys
    [[ -z "$key" ]] && continue
    
    env_vars["$key"]="$value"
    [[ "$VERBOSE" == "true" ]] && echo "  + $key=$value"
done < "$TEMP_DIR/env_diff.txt"

# Generate plist content
log "Generating LaunchAgent plist..."
cat > "$TEMP_DIR/environment.plist" <<'EOF'
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.user.environment</string>
    <key>ProgramArguments</key>
    <array>
        <string>sh</string>
        <string>-c</string>
        <string>
EOF

# Build the launchctl commands
commands=""
for key in "${!env_vars[@]}"; do
    # Escape the value for shell
    value="${env_vars[$key]}"
    # Escape double quotes and backslashes
    value="${value//\\/\\\\}"
    value="${value//\"/\\\"}"
    commands+="            launchctl setenv \"$key\" \"$value\"\n"
done

# Complete the plist
echo -n "$commands" >> "$TEMP_DIR/environment.plist"
cat >> "$TEMP_DIR/environment.plist" <<'EOF'
        </string>
    </array>
    <key>RunAtLoad</key>
    <true/>
</dict>
</plist>
EOF

# Validate plist
if ! plutil -lint "$TEMP_DIR/environment.plist" >/dev/null 2>&1; then
    error "Generated plist is invalid!"
    exit 1
fi

# Show what would be done in dry-run mode
if [[ "$DRY_RUN" == "true" ]]; then
    log "DRY RUN: Would update $PLIST_PATH"
    echo "--- New environment variables ---"
    for key in "${!env_vars[@]}"; do
        echo "$key=${env_vars[$key]}"
    done
    echo "--- Plist content ---"
    cat "$TEMP_DIR/environment.plist"
    exit 0
fi

# Backup existing plist if it exists
if [[ -f "$PLIST_PATH" ]]; then
    backup_path="$PLIST_PATH.backup.$(date +%Y%m%d_%H%M%S)"
    cp "$PLIST_PATH" "$backup_path"
    log "Backed up existing plist to $backup_path"
fi

# Create LaunchAgents directory if needed
mkdir -p "$(dirname "$PLIST_PATH")"

# Install the new plist
cp "$TEMP_DIR/environment.plist" "$PLIST_PATH"
log "Updated $PLIST_PATH"

# Unload and reload the LaunchAgent
if launchctl list | grep -q "com.user.environment"; then
    log "Reloading LaunchAgent..."
    launchctl unload "$PLIST_PATH" 2>/dev/null || true
fi
launchctl load "$PLIST_PATH"

# Apply changes immediately to current session
log "Applying environment variables to current session..."
for key in "${!env_vars[@]}"; do
    launchctl setenv "$key" "${env_vars[$key]}"
done

log "✅ Environment variables synced successfully!"
log "   ${#env_vars[@]} variables updated"
log "   Changes will fully take effect for new applications"
log "   For complete effect, log out and log back in"