"""Tkinker gui for pylint"""

import os
import sys
import re
import Queue
from threading import Thread
from Tkinter import (Tk, Frame, Listbox, Entry, Label, Button, Scrollbar,
                     Checkbutton, Radiobutton, IntVar, StringVar)
from Tkinter import (TOP, LEFT, RIGHT, BOTTOM, END, X, Y, BOTH, SUNKEN, W,
                     HORIZONTAL, DISABLED, NORMAL, W, E)
from tkFileDialog import askopenfilename, askdirectory

import pylint.lint
from pylint.reporters.guireporter import GUIReporter

HOME = os.path.expanduser('~/')
HISTORY = '.pylint-gui-history'
COLORS = {'(I)':'lightblue',
          '(C)':'blue', '(R)':'darkblue',
          '(W)':'black', '(E)':'darkred',
          '(F)':'red'}

class BasicStream:
    '''
    used in gui reporter instead of writing to stdout, it is written to
    this stream and saved in contents
    '''
    def __init__(self, gui):
        """init"""
        self.curline = ""
        self.gui = gui
        self.contents = []
        self.outdict = {}
        self.currout = None
        self.nextTitle = None

    def write(self, text):
        """write text to the stream"""
        if re.match('^--+$', text.strip()) or re.match('^==+$', text.strip()):
            if self.currout:
                self.outdict[self.currout].remove(self.nextTitle)
                self.outdict[self.currout].pop()
            self.currout = self.nextTitle
            self.outdict[self.currout] = ['']

        if text.strip():
            self.nextTitle = text.strip()

        if text.startswith('\n'):
            self.contents.append('')
            if self.currout: self.outdict[self.currout].append('')
        self.contents[-1] += text.strip('\n')
        if self.currout: self.outdict[self.currout][-1] += text.strip('\n')
        if text.endswith('\n') and text.strip():
            self.contents.append('')
            if self.currout: self.outdict[self.currout].append('')

    def fix_contents(self):
        """finalize what the contents of the dict should look like before output"""
        for item in self.outdict:
            numEmpty = self.outdict[item].count('')
            for i in range(numEmpty):
                self.outdict[item].remove('')
            if self.outdict[item]:
                self.outdict[item].pop(0)

    def output_contents(self):
        """output contents of dict to the gui, and set the rating"""
        self.fix_contents()
        self.gui.tabs = self.outdict
        try:
            self.gui.rating.set(self.outdict['Global evaluation'][0])
        except:
            self.gui.rating.set('Error')
        self.gui.refresh_results_window()

        #reset stream variables for next run
        self.contents = []
        self.outdict = {}
        self.currout = None
        self.nextTitle = None


class LintGui:
    """Build and control a window to interact with pylint"""

    def __init__(self, root=None):
        """init"""
        self.root = root or Tk()
        self.root.title('Pylint')
        #reporter
        self.reporter = None
        #message queue for output from reporter
        self.msg_queue = Queue.Queue()
        self.msgs = []
        self.filenames = []
        self.rating = StringVar()
        self.tabs = {}
        self.report_stream = BasicStream(self)
        #gui objects
        self.lbMessages = None
        self.showhistory = None
        self.results = None
        self.btnRun = None
        self.information_box = None
        self.convention_box = None
        self.refactor_box = None
        self.warning_box = None
        self.error_box = None
        self.fatal_box = None
        self.txtModule = None
        self.status = None
        self.msg_type_dict = None
        self.init_gui()

    def init_gui(self):
        """init helper"""
        #setting up frames
        top_frame = Frame(self.root)
        mid_frame = Frame(self.root)
        radio_frame = Frame(self.root)
        res_frame = Frame(self.root)
        msg_frame = Frame(self.root)
        check_frame = Frame(self.root)
        history_frame = Frame(self.root)
        btn_frame = Frame(self.root)
        rating_frame = Frame(self.root)
        top_frame.pack(side=TOP, fill=X)
        mid_frame.pack(side=TOP, fill=X)
        history_frame.pack(side=TOP, fill=BOTH, expand=True)
        radio_frame.pack(side=TOP, fill=BOTH, expand=True)
        rating_frame.pack(side=TOP, fill=BOTH, expand=True)
        res_frame.pack(side=TOP, fill=BOTH, expand=True)
        check_frame.pack(side=TOP, fill=BOTH, expand=True)
        msg_frame.pack(side=TOP, fill=BOTH, expand=True)
        btn_frame.pack(side=TOP, fill=X)

        #Message ListBox
        rightscrollbar = Scrollbar(msg_frame)
        rightscrollbar.pack(side=RIGHT, fill=Y)
        bottomscrollbar = Scrollbar(msg_frame, orient=HORIZONTAL)
        bottomscrollbar.pack(side=BOTTOM, fill=X)
        self.lbMessages = Listbox(msg_frame,
                  yscrollcommand=rightscrollbar.set,
                  xscrollcommand=bottomscrollbar.set,
                  bg="white")
        self.lbMessages.pack(expand=True, fill=BOTH)
        rightscrollbar.config(command=self.lbMessages.yview)
        bottomscrollbar.config(command=self.lbMessages.xview)

        #History ListBoxes
        rightscrollbar2 = Scrollbar(history_frame)
        rightscrollbar2.pack(side=RIGHT, fill=Y)
        bottomscrollbar2 = Scrollbar(history_frame, orient=HORIZONTAL)
        bottomscrollbar2.pack(side=BOTTOM, fill=X)
        self.showhistory = Listbox(history_frame,
                    yscrollcommand=rightscrollbar2.set,
                    xscrollcommand=bottomscrollbar2.set,
                    bg="white")
        self.showhistory.pack(expand=True, fill=BOTH)
        rightscrollbar2.config(command=self.showhistory.yview)
        bottomscrollbar2.config(command=self.showhistory.xview)
        self.showhistory.bind('<Double-Button-1>', self.select_recent_file)
        self.set_history_window()

        #status bar
        self.status = Label(self.root, text="", bd=1, relief=SUNKEN, anchor=W)
        self.status.pack(side=BOTTOM, fill=X)

        #labels
        self.lblRatingLabel = Label(rating_frame, text='Rating:')
        self.lblRatingLabel.pack(side=LEFT)
        self.lblRating = Label(rating_frame, textvariable=self.rating)
        self.lblRating.pack(side=LEFT)
        Label(mid_frame, text='Recently Used:').pack(side=LEFT)
        Label(top_frame, text='Module or package').pack(side=LEFT)

        #file textbox
        self.txtModule = Entry(top_frame, background='white')
        self.txtModule.bind('<Return>', self.run_lint)
        self.txtModule.pack(side=LEFT, expand=True, fill=X)

        #results box
        rightscrollbar = Scrollbar(res_frame)
        rightscrollbar.pack(side=RIGHT, fill=Y)
        bottomscrollbar = Scrollbar(res_frame, orient=HORIZONTAL)
        bottomscrollbar.pack(side=BOTTOM, fill=X)
        self.results = Listbox(res_frame,
                  yscrollcommand=rightscrollbar.set,
                  xscrollcommand=bottomscrollbar.set,
                  bg="white", font="Courier")
        self.results.pack(expand=True, fill=BOTH, side=BOTTOM)
        rightscrollbar.config(command=self.results.yview)
        bottomscrollbar.config(command=self.results.xview)

        #buttons
        Button(top_frame, text='Open', command=self.file_open).pack(side=LEFT)
        Button(top_frame, text='Open Package', 
               command=(lambda : self.file_open(package=True))).pack(side=LEFT)

        self.btnRun = Button(top_frame, text='Run', command=self.run_lint)
        self.btnRun.pack(side=LEFT)
        Button(btn_frame, text='Quit', command=self.quit).pack(side=BOTTOM)

        #radio buttons
        self.information_box = IntVar()
        self.convention_box = IntVar()
        self.refactor_box = IntVar()
        self.warning_box = IntVar()
        self.error_box = IntVar()
        self.fatal_box = IntVar()
        i = Checkbutton(check_frame, text="Information", fg=COLORS['(I)'],
                        variable=self.information_box, command=self.refresh_msg_window)
        c = Checkbutton(check_frame, text="Convention", fg=COLORS['(C)'],
                        variable=self.convention_box, command=self.refresh_msg_window)
        r = Checkbutton(check_frame, text="Refactor", fg=COLORS['(R)'],
                        variable=self.refactor_box, command=self.refresh_msg_window)
        w = Checkbutton(check_frame, text="Warning", fg=COLORS['(W)'],
                        variable=self.warning_box, command=self.refresh_msg_window)
        e = Checkbutton(check_frame, text="Error", fg=COLORS['(E)'],
                        variable=self.error_box, command=self.refresh_msg_window)
        f = Checkbutton(check_frame, text="Fatal", fg=COLORS['(F)'],
                        variable=self.fatal_box, command=self.refresh_msg_window)
        i.select()
        c.select()
        r.select()
        w.select()
        e.select()
        f.select()
        i.pack(side=LEFT)
        c.pack(side=LEFT)
        r.pack(side=LEFT)
        w.pack(side=LEFT)
        e.pack(side=LEFT)
        f.pack(side=LEFT)

        #check boxes
        self.box = StringVar()
        # XXX should be generated
        report = Radiobutton(radio_frame, text="Report", variable=self.box,
                             value="Report", command=self.refresh_results_window)
        rawMet = Radiobutton(radio_frame, text="Raw metrics", variable=self.box,
                             value="Raw metrics", command=self.refresh_results_window)
        dup = Radiobutton(radio_frame, text="Duplication", variable=self.box,
                          value="Duplication", command=self.refresh_results_window)
        ext = Radiobutton(radio_frame, text="External dependencies",
                          variable=self.box, value="External dependencies",
                          command=self.refresh_results_window)
        stat = Radiobutton(radio_frame, text="Statistics by type",
                           variable=self.box, value="Statistics by type",
                           command=self.refresh_results_window)
        msgCat = Radiobutton(radio_frame, text="Messages by category",
                             variable=self.box, value="Messages by category",
                             command=self.refresh_results_window)
        msg = Radiobutton(radio_frame, text="Messages", variable=self.box,
                            value="Messages", command=self.refresh_results_window)
        report.select()
        report.grid(column=0, row=0, sticky=W)
        rawMet.grid(column=1, row=0, sticky=W)
        dup.grid(column=2, row=0, sticky=W)
        msg.grid(column=3, row=0, sticky=E)
        stat.grid(column=0, row=1, sticky=W)
        msgCat.grid(column=1, row=1, sticky=W)
        ext.grid(column=2, row=1, columnspan=2, sticky=W)

        #dictionary for check boxes and associated error term
        self.msg_type_dict = {
            'I' : lambda : self.information_box.get() == 1,
            'C' : lambda : self.convention_box.get() == 1,
            'R' : lambda : self.refactor_box.get() == 1,
            'E' : lambda : self.error_box.get() == 1,
            'W' : lambda : self.warning_box.get() == 1,
            'F' : lambda : self.fatal_box.get() == 1
        }
        self.txtModule.focus_set()


    def select_recent_file(self, event):
        """adds the selected file in the history listbox to the Module box"""
        if not self.showhistory.size():
            return

        selected = self.showhistory.curselection()
        item = self.showhistory.get(selected)
        #update module
        self.txtModule.delete(0, END)
        self.txtModule.insert(0, item)

    def refresh_msg_window(self):
        """refresh the message window with current output"""
        #clear the window
        self.lbMessages.delete(0, END)
        for msg in self.msgs:
            if (self.msg_type_dict.get(msg[0])()):
                msg_str = self.convert_to_string(msg)
                self.lbMessages.insert(END, msg_str)
                fg_color = COLORS.get(msg_str[:3], 'black')
                self.lbMessages.itemconfigure(END, fg=fg_color)

    def refresh_results_window(self):
        """refresh the results window with current output"""
        #clear the window
        self.results.delete(0, END)
        try:
            for res in self.tabs[self.box.get()]:
                self.results.insert(END, res)
        except:
            pass

    def convert_to_string(self, msg):
        """make a string representation of a message"""
        if (msg[2] != ""):
            return "(" + msg[0] + ") " + msg[1] + "." + msg[2] + " [" + msg[3] + "]: " + msg[4]
        else:
            return "(" + msg[0] + ") " + msg[1] + " [" + msg[3] + "]: " + msg[4]

    def process_incoming(self):
        """process the incoming messages from running pylint"""
        while self.msg_queue.qsize():
            try:
                msg = self.msg_queue.get(0)
                if msg == "DONE":
                    self.report_stream.output_contents()
                    return False

                #adding message to list of msgs
                self.msgs.append(msg)

                #displaying msg if message type is selected in check box
                if (self.msg_type_dict.get(msg[0])()):
                    msg_str = self.convert_to_string(msg)
                    self.lbMessages.insert(END, msg_str)
                    fg_color = COLORS.get(msg_str[:3], 'black')
                    self.lbMessages.itemconfigure(END, fg=fg_color)

            except Queue.Empty:
                pass
        return True

    def periodic_call(self):
        """determine when to unlock the run button"""
        if self.process_incoming():
            self.root.after(100, self.periodic_call)
        else:
            #enabling button so it can be run again
            self.btnRun.config(state=NORMAL)

    def mainloop(self):
        """launch the mainloop of the application"""
        self.root.mainloop()

    def quit(self, _=None):
        """quit the application"""
        self.root.quit()

    def halt(self):
        """program halt placeholder"""
        return

    def file_open(self, package=False, _=None):
        """launch a file browser"""
        if not package:
            filename = askopenfilename(parent=self.root, filetypes=[('pythonfiles', '*.py'),
                                                    ('allfiles', '*')], title='Select Module')
        else:
            filename = askdirectory(title="Select A Folder", mustexist=1)

        if filename == ():
            return

        self.txtModule.delete(0, END)
        self.txtModule.insert(0, filename)

    def update_filenames(self):
        """update the list of recent filenames"""
        filename = self.txtModule.get()
        if not filename:
            filename = os.getcwd()
        if filename+'\n' in self.filenames:
            index = self.filenames.index(filename+'\n')
            self.filenames.pop(index)

        #ensure only 10 most recent are stored
        if len(self.filenames) == 10:
            self.filenames.pop()
        self.filenames.insert(0, filename+'\n')

    def set_history_window(self):
        """update the history window with info from the history file"""
        #clear the window
        self.showhistory.delete(0, END)
        # keep the last 10 most recent files
        try:
            view_history = open(HOME+HISTORY, 'r')
            for hist in view_history.readlines():
                if not hist in self.filenames:
                    self.filenames.append(hist)
                self.showhistory.insert(END, hist.split('\n')[0])
            view_history.close()
        except IOError:
            # do nothing since history file will be created later
            return

    def run_lint(self, _=None):
        """launches pylint"""
        self.update_filenames()
        self.root.configure(cursor='watch')
        self.reporter = GUIReporter(self, output=self.report_stream)
        module = self.txtModule.get()
        if not module:
            module = os.getcwd()

        #cleaning up msgs and windows
        self.msgs = []
        self.lbMessages.delete(0, END)
        self.tabs = {}
        self.results.delete(0, END)
        self.btnRun.config(state=DISABLED)

        #setting up a worker thread to run pylint
        worker = Thread(target=lint_thread, args=(module, self.reporter, self,))
        self.periodic_call()
        worker.start()

        # Overwrite the .pylint-gui-history file with all the new recently added files
        # in order from filenames but only save last 10 files
        write_history = open(HOME+HISTORY, 'w')
        write_history.writelines(self.filenames)
        write_history.close()
        self.set_history_window()

        self.root.configure(cursor='')


def lint_thread(module, reporter, gui):
    """thread for pylint"""
    gui.status.text = "processing module(s)"
    lint_obj = pylint.lint.Run(args=[module], reporter=reporter, exit=False)
    gui.msg_queue.put("DONE")


def Run(args):
    """launch pylint gui from args"""
    if args:
        print 'USAGE: pylint-gui\n launch a simple pylint gui using Tk'
        return
    gui = LintGui()
    gui.mainloop()

if __name__ == '__main__':
    Run(sys.argv[1:])