#!/usr/bin/env python3

import sys, os, socket, fnmatch

SRC=os.path.expanduser("~/dotfiles/")
DST=os.path.expanduser("~/")
try:
    HOSTNAME=socket.gethostbyaddr(socket.gethostname())[0]
except:
    HOSTNAME="unknown"

def linkfile(prefix, srcfile, dstfile):
    srcpath = os.path.join(prefix, srcfile)
    dstpath = os.path.join(DST, dstfile)
    if os.path.exists(dstpath):
        if os.path.islink(dstpath):
            print(dstpath, "already exists as a link; removing it")
            os.unlink(dstpath)
        else:
            ok = input(dstpath + " already exists; remove it? (y/n)")
            if (ok.startswith("y")):
                print("removing", dstpath)
                os.unlink(dstpath)
            else:
                print("ignoring", dstpath)
                return
    print("linking in", srcpath, "as", dstpath)
    os.symlink(os.path.join(prefix, srcfile),
               os.path.join(DST, dstfile))

def linkasdotfile(prefix, name):
    linkfile(prefix, name, "."+name)
   
def ignore(prefix, filename):
    pass

def linkcontents(prefix, name):
    contents = os.listdir(os.path.join(prefix, name))
    if not os.path.exists(os.path.join(DST, "."+name)):
        print("making directory", (os.path.join(DST, "."+name)))
        os.mkdir(os.path.join(DST, "."+name))
    for x in contents:
        if x.startswith("."):
            continue                    # ignore .svn, etc
        if x.startswith("#") or x.endswith("~"):
            continue                    # ignore editor cruft
        linkasdotfile(prefix, os.path.join(name,x))

SPECIAL = {"local" : ignore,
           "install-dotfiles" : ignore,
           "ssh" : linkcontents,
           "subversion" : linkcontents,
           "elisp" : (lambda p,x : linkfile(p,
                                            os.path.join(x,"emacs.el"),
                                            ".emacs"))
          }

LOCAL = {"csail" : "*.csail.mit.edu",
         "lcs" : "*.lcs.mit.edu",
         "midnight-anchovy" : "18.141.0.*",
         "clamshell" : "clamshell.ambulatoryclam.net",
         "none" : "unknown"}

def traversedir(dirname):
    for x in os.listdir(dirname):
        if x.startswith("."):
            continue                    # ignore .svn, etc
        if x.startswith("#") or x.endswith("~"):
            continue                    # ignore editor cruft
        if x in SPECIAL:
            SPECIAL[x](dirname, x)
        else:
            linkasdotfile(dirname, x)

traversedir(SRC)

localdir = None

try:
    localdir = file(os.path.expanduser("~/.dotfiles-local")).readline()
    print("Saved local dir:", localdir)
except:
    pass

if len(sys.argv) == 2:
    localdir = sys.argv[1]
    print("Using (and saving) specified local dir:", localdir)
    localdirfile = file(os.path.expanduser("~/.dotfiles-local"), "w")
    localdirfile.write(localdir)

if not localdir:
    print("I think my hostname is", HOSTNAME)
    for d in os.listdir(os.path.join(SRC, "local")):
        if d.startswith("."):
            continue                        # ignore .svn, etc
        if d not in LOCAL:
            print("didn't find a LOCAL entry for", d)
            continue
        if fnmatch.fnmatch(HOSTNAME, LOCAL[d]):
            print("Guessing local dir as:", d)
            localdir = d
            break

if localdir:
    print("Installing local files for", localdir)
    traversedir(os.path.join(SRC, "local", localdir))