#!/bin/bash

# git-worktree-ai - Create git worktrees and with linked AI agent configuration files
#
# Usage:
#   ./git-worktree-ai <worktree-path> <branch-name>
#   git worktree-ai <worktree-path> <branch-name>  (when added as git alias)
#
# Examples:
#   ./git-worktree-ai ../feature-auth feature-auth
#   git worktree-ai ../bugfix-login bugfix-login

set -e

CONFIG_FILES=(
    # Claude Code
    "CLAUDE.local.md"
    "CLAUDE.md"
    ".claude"
    ".mcp.json"
    # VS Code config
    ".vscode"                    # Directory: entire .vscode folder
    # env files
    ".env*"
)

if [ $# -lt 2 ]; then
    echo "Missing required argument".
    echo "Usage $0 <worktree-path> <branch-name>"
    exit 1
fi

WORKTREE_PATH="$1"
BRANCH_NAME="$2"

# Validate that we are in a git repo
if ! git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
    echo "Not inside a git repository"
    exit 1
fi

if [ -e "$WORKTREE_PATH" ]; then
    echo "Path $WORKTREE_PATH already exists"
    exit 1
fi

# Check if branch already exists
if git show-ref --verify --quiet "refs/heads/$BRANCH_NAME"; then
    echo "Branch $BRANCH_NAME already exists"
    exit 1
fi

echo "Creating worktree $WORKTREE_PATH with new branch $BRANCH_NAME"
if ! git worktree add "$WORKTREE_PATH" -b "$BRANCH_NAME"; then
    echo "Faild to create worktree"
    exit 1
else
    echo "Worktree created successfully"
fi

cd "$WORKTREE_PATH"

# Find the main repository using git-common-dir
echo "Finding main repository..."
MAIN_REPO=$(dirname "$(git rev-parse --git-common-dir)")
MAIN_REPO=$(cd "$MAIN_REPO" && pwd)  # Get absolute path
echo "Main repository at $MAIN_REPO"

# Function to expand wildcards and return matching files/directories
expand_pattern() {
    local pattern="$1"
    local base_dir="$2"

    # Change to base directory and use shell globbing
    (
        cd "$base_dir"
        # Set nullglob so patterns with no matches expand to nothing
        shopt -s nullglob
        # Expand the pattern
        for match in $pattern; do
            echo "$match"
        done
    )
}

for pattern in "${CONFIG_FILES[@]}"; do
    echo "$pattern"
    # Expand wildcards in the main repository
    matches=$(expand_pattern "$pattern" "$MAIN_REPO")

    # Process each match
    while IFS= read -r file; do
        # skip empty lines
        [ -z "$file" ] && continue

        SOURCE_PATH="$MAIN_REPO/$file"
        TARGET_PATH="$file"

        if [ -f "$SOURCE_PATH" ]; then
            # Handle files: create parent directory if needed
            PARENT_DIR="$(dirname "$TARGET_PATH")"
            if [ "$PARENT_DIR" != "." ]; then
                mkdir -p "$PARENT_DIR"
            fi
            ln -sf "$SOURCE_PATH" "$TARGET_PATH"
            echo "Linked file: $file"

        elif [ -d "$SOURCE_PATH" ]; then
            # Handle directories: create parent directory if needed, remove target if it exists
            PARENT_DIR="$(dirname "$TARGET_PATH")"
            if [ "$PARENT_DIR" != "." ]; then
                mkdir -p "$PARENT_DIR"
            fi

            # Remove target if it exists (could be empty dir created by mistake)
            if [ -e "$TARGET_PATH" ] && [ ! -L "$TARGET_PATH" ]; then
                rm -rf "$TARGET_PATH"
            fi

            ln -sf "$SOURCE_PATH" "$TARGET_PATH"
            echo "Linked directory: $file"
        else
            echo "Skipped $file. What is this?"
        fi


    done <<< "$matches"
done