from datetime import datetime
import os
import socket
import sys
import time


class Debug(object):
    def __init__(self):
        self.last_log_time = None

    def enable(self):
        self.enable_log()
        self.enable_debugger()

    def enable_log(self):
        self.log = self._log
        self.raw_log = self._raw_log
        self.log_file = open(os.path.join(os.path.dirname(os.path.dirname(__file__)), "debug.log"), "w")
        self.log("Debug logging enabled.")

    def enable_debugger(self):
        # How to debug Ink/Stitch:
        #
        # 1. Install LiClipse (liclipse.com) -- no need to install Eclipse first
        # 2. Start debug server as described here: http://www.pydev.org/manual_adv_remote_debugger.html
        #    * follow the "Note:" to enable the debug server menu item
        # 3. Create a file named "DEBUG" next to inkstitch.py in your git clone.
        # 4. Run any extension and PyDev will start debugging.

        try:
            import pydevd
        except ImportError:
            self.log("importing pydevd failed (debugger disabled)")

        # pydevd likes to shout about errors to stderr whether I want it to or not
        with open(os.devnull, 'w') as devnull:
            stderr = sys.stderr
            sys.stderr = devnull

            try:
                pydevd.settrace()
            except socket.error, error:
                self.log("Debugging: connection to pydevd failed: %s", error)
                self.log("Be sure to run 'Start debugging server' in PyDev to enable debugging.")
            else:
                self.log("Enabled PyDev debugger.")

            sys.stderr = stderr

    def _noop(self, *args, **kwargs):
        pass

    log = _noop
    raw_log = _noop

    def _log(self, message, *args):
        if self.last_log_time:
            message = "(+%s) %s" % (datetime.now() - self.last_log_time, message)

        self.raw_log(message, *args)

    def _raw_log(self, message, *args):
        now = datetime.now()
        timestamp = now.isoformat()
        self.last_log_time = now

        print >> self.log_file, timestamp, message % args
        self.log_file.flush()

    def time(self, func):
        def decorated(*args, **kwargs):
            self.raw_log("entering %s()", func.func_name)
            start = time.time()
            result = func(*args, **kwargs)
            end = time.time()
            self.raw_log("leaving %s(), duration = %s", func.func_name, round(end - start, 6))
            return result

        return decorated


debug = Debug()
enable = debug.enable