#!/usr/bin/env python

"""Initialize your dotfiles setup.

Usage: setup [--install]

This will create symlinks in $HOME for every file listed in ./home in this
repository. It will NOT delete existing files in $HOME; use the --install
option to delete existing files.

This script should work in any version of Python above v2.5"""

import sys
import os
import os.path
import shutil
import re
import subprocess

# Install? (deletes existing files in $HOME).
install = "--install" in sys.argv

# Get the path to the git repo.
basedir = os.path.abspath(os.path.dirname(__file__))
homedir = os.environ.get("HOME", ".")
source  = os.path.join(basedir, "home")

print("Setting up .dotfiles")
print("====================")
print("")
if install:
    print("* Install mode: will delete files in $HOME and set up symlinks!")

# Set up the submodules first.
print("Initializing git submodules...")
os.chdir(basedir)
subprocess.call(["git", "submodule", "init"])
subprocess.call(["git", "submodule", "update"])
os.chdir(homedir)
print("Submodules updated!")
print("")

def crawl(folder):
    """Recursively crawl a folder. Directories will be created relative to
    $HOME, and files in those directories will be symlinked."""
    for item in sorted(os.listdir(folder)):
        # Resolve the path to this file relative to $HOME and the absolute
        # path to the symlink target. First get the path to the target.
        target = os.path.join(folder, item)

        # Remove the source dir prefix from it to get the path relative
        # to the "./home" folder, then use that for $HOME.
        path   = re.sub(r'^%s/' % source, '', target)
        home   = os.path.join(homedir, path)

        # If the target is a directory, make sure it exists relative to $HOME.
        if os.path.isdir(target):
            if not os.path.isdir(home):
                print("Create directory:", home)
                os.mkdir(home)

            # Recursively crawl it.
            crawl(target)
            continue

        # Otherwise it's a file. In install mode, delete the existing file.
        if os.path.exists(home) or os.path.islink(home):
            if install:
                print("Delete:", home)
                os.unlink(home)
            elif not os.path.islink(home):
                print("Found existing (non-link file), but not in --install mode:", home)
                continue

        # Already linked?
        if os.path.islink(home):
            link = os.readlink(home)
            if link == target:
                print("Already linked:", home)
                continue
            else:
                print("Delete existing link:", home)
                os.unlink(home)

        # Link it.
        print("Link: %s -> %s" % (home, target))
        os.symlink(target, home)

crawl(source)

# vim:expandtab