# -*- coding: utf-8 -*-

# Copyright (c) 2014 - 2018 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing the VCS status monitor thread class for Git.
"""

from __future__ import unicode_literals
try:
    str = unicode
except NameError:
    pass

from PyQt5.QtCore import QProcess

from VCS.StatusMonitorThread import VcsStatusMonitorThread

import Preferences


class GitStatusMonitorThread(VcsStatusMonitorThread):
    """
    Class implementing the VCS status monitor thread class for Git.
    """
    ConflictStates = ["AA", "AU", "DD", "DU", "UA", "UD", "UU"]
    
    def __init__(self, interval, project, vcs, parent=None):
        """
        Constructor
        
        @param interval new interval in seconds (integer)
        @param project reference to the project object (Project)
        @param vcs reference to the version control object
        @param parent reference to the parent object (QObject)
        """
        VcsStatusMonitorThread.__init__(self, interval, project, vcs, parent)
        
        self.__ioEncoding = Preferences.getSystem("IOEncoding")
        
        self.__client = None
        self.__useCommandLine = False
    
    def _performMonitor(self):
        """
        Protected method implementing the monitoring action.
        
        This method populates the statusList member variable
        with a list of strings giving the status in the first column and the
        path relative to the project directory starting with the third column.
        The allowed status flags are:
        <ul>
            <li>"A" path was added but not yet comitted</li>
            <li>"M" path has local changes</li>
            <li>"O" path was removed</li>
            <li>"R" path was deleted and then re-added</li>
            <li>"U" path needs an update</li>
            <li>"Z" path contains a conflict</li>
            <li>" " path is back at normal</li>
        </ul>
        
        @return tuple of flag indicating successful operation (boolean) and
            a status message in case of non successful operation (string)
        """
        self.shouldUpdate = False
        
        # step 1: get overall status
        args = self.vcs.initCommand("status")
        args.append('--porcelain')
        
        output = ""
        error = ""
        process = QProcess()
        process.setWorkingDirectory(self.projectDir)
        process.start('git', args)
        procStarted = process.waitForStarted(5000)
        if procStarted:
            finished = process.waitForFinished(300000)
            if finished and process.exitCode() == 0:
                output = str(process.readAllStandardOutput(),
                             self.__ioEncoding, 'replace')
            else:
                process.kill()
                process.waitForFinished()
                error = str(process.readAllStandardError(),
                            self.__ioEncoding, 'replace')
        else:
            process.kill()
            process.waitForFinished()
            error = self.tr("Could not start the Git process.")
        
        if error:
            return False, error
        
        states = {}
        for line in output.splitlines():
            flags = line[:2]
            name = line[3:].split(" -> ")[-1]
            if flags in self.ConflictStates:
                states[name] = "Z"
            if flags[0] in "AMDR":
                if flags[0] == "D":
                    status = "O"
                elif flags[0] == "R":
                    status = "A"
                else:
                    status = flags[0]
                states[name] = status
            elif flags[1] in "MD":
                if flags[1] == "D":
                    status = "O"
                else:
                    status = flags[1]
                states[name] = status
        
        # step 2: collect the status to be reported back
        for name in states:
            try:
                if self.reportedStates[name] != states[name]:
                    self.statusList.append(
                        "{0} {1}".format(states[name], name))
            except KeyError:
                self.statusList.append("{0} {1}".format(states[name], name))
        for name in self.reportedStates.keys():
            if name not in states:
                self.statusList.append("  {0}".format(name))
        self.reportedStates = states
        
        return True, \
            self.tr("Git status checked successfully")
    
    def _shutdown(self):
        """
        Protected method performing shutdown actions.
        """
        if self.__client:
            self.__client.stopServer()
