from kivy.uix.label import Label
from kivy.core.window import Window
from kivy.graphics import Color,Rectangle
import glob
import os.path

class Command_prompt(Label):
    
    def __init__(self,app,**kwargs):
        # app is used to share information between widgets
        self.app=app

        # insert mode
        self.insert=False

        # width of a letter
        self.char_width=9

        # cursor position
        self.cursor=0

        # the text, with no color information
        self.raw_text=""

        # a one-time message that shows up over the bar
        self.message=""

        # array of command with arguments
        self.argv=[]

        # display characters from window_offset onwards (for text wrapping)
        self.window_offset=0

        # init Label
        super(Command_prompt,self).__init__(**kwargs)

        self.keyboard = Window.request_keyboard(None,self,"text")
        self.keyboard.bind(on_textinput=self.on_textinput,on_key_down=self.on_key_down)

        self.draw()


    def draw(self):

        # background
        with self.canvas.before:
            Color(0,0,0)
            Rectangle(pos=self.pos,size=self.size)

        # if message is not empty, draw message instead
        if self.message!="":
            # do not wrap
            self.text=self.message[:min(len(self.message),int(self.width/self.char_width))]
            self.message=""
            return

        # wrap text
        window_size=int(self.width/self.char_width)
        if self.cursor>=self.window_offset+window_size:
            self.window_offset=self.cursor-window_size+1
        elif self.cursor<self.window_offset:
            self.window_offset=self.cursor
        # do not stop right before ':'
        if self.window_offset==1:
            self.window_offset=0

        # cursor
        with self.canvas.before:
            Color(1,1,1)
            # wrap cursor position
            Rectangle(pos=(self.pos[0]+(self.cursor-self.window_offset)*self.char_width,self.pos[1]),size=(self.char_width,self.height))

        # make text under cursor black
        end=min(len(self.raw_text),self.window_offset+window_size)
        if self.cursor<end:
            self.text=self.raw_text[self.window_offset:self.cursor]+"[color=000]"+self.raw_text[self.cursor]+"[/color]"+self.raw_text[self.cursor+1:end]
        else:
            self.text=self.raw_text[self.window_offset:end]


    def on_key_down(self, keyboard, keycode, text, modifiers):
        #print(keycode,text,modifiers)
        if self.insert:
            # process modifiers
            mods=self.process_modifiers(modifiers)

            # process command
            if keycode[1]=="enter":
                self.insert=False
                self.run_command()
                self.set_text("")

            # move
            elif keycode[1]=="left":
                self.move_cursor_relative(-1)
            elif keycode[1]=="right":
                self.move_cursor_relative(1)
            elif mods==['c'] and text=="a":
                self.move_cursor(1)
            elif mods==['c'] and text=="e":
                self.move_cursor(len(self.raw_text))

            # delete
            elif keycode[1]=="backspace":
                self.backspace()
            elif keycode[1]=="delete":
                self.delete_forward()
            elif mods==['c'] and text=="k":
                self.delete_all_forward()

            # tab completion
            elif keycode[1]=="tab":
                self.tab_complete()

    def on_textinput(self,window,text):
        # reset status_bar
        self.app.status_bar.draw()
        if self.insert:
            self.append_text_at_cursor(text)
        elif text==':':
            self.append_text_at_cursor(text)
            self.insert=True


    # get modifiers from list
    # returns an alphabetically ordered array of characters
    # 'a' is alt
    # 'c' is ctrl
    # 'm' is meta
    # 's' is shift
    # ignore all others
    def process_modifiers(self,modifiers):
        out=[]
        for mod in modifiers:
            if mod=="alt":
                out.append('a')
            elif mod=="ctrl":
                out.append('c')
            elif mod=="meta":
                out.append('m')
            elif mod=="shift":
                out.append('s')
        out.sort()
        return out
                


    # append to text at position of cursor
    def append_text_at_cursor(self,text):
        if self.cursor==len(self.raw_text):
            self.raw_text+=text
        else:
            self.raw_text=self.raw_text[:self.cursor]+text+self.raw_text[self.cursor:]
        self.cursor+=len(text)
        self.draw()

    # delete before cursor
    def backspace(self):
        # do not delete leading ':'
        if self.cursor==1:
            return
        if self.cursor==len(self.raw_text):
            self.raw_text=self.raw_text[:self.cursor-1]
        else:
            self.raw_text=self.raw_text[:self.cursor-1]+self.raw_text[self.cursor:]
        self.cursor-=1
        self.draw()
    # delete after cursor
    def delete_forward(self):
        if self.cursor==len(self.raw_text):
            return
        else:
            self.raw_text=self.raw_text[:self.cursor]+self.raw_text[self.cursor+1:]
        self.draw()
    # delete until end of line(self):
    def delete_all_forward(self):
        if self.cursor==len(self.raw_text):
            return
        else:
            self.raw_text=self.raw_text[:self.cursor]
        self.draw()
        

    # set text in prompt
    def set_text(self,text):
        self.raw_text=text
        self.cursor=len(text)
        self.draw()


    # move cursor n steps to right (left if negative)
    def move_cursor_relative(self,n):
        if n==0 or (n>0 and self.cursor==len(self.raw_text)) or (n<0 and self.cursor==0):
            return
        self.cursor=max(1,min(len(self.raw_text),self.cursor+n))
        self.draw()

    # move cursor to absolute position
    def move_cursor(self,n):
        self.cursor=max(1,min(len(self.raw_text),n))
        self.draw()


    # parse text as argv
    def parse_argv(self):
        # init
        self.argv=[""]

        # return position of cursor
        cursor=(0,0)

        # whether inside quotes
        single_quoted=False
        double_quoted=False
        # whether after '\'
        backslashed=False

        # start after ':'
        # proceed one character at a time
        for i in range(1,len(self.raw_text)):
            char=self.raw_text[i]

            # split argument
            if single_quoted==False and double_quoted==False and backslashed==False and char==' ':
                # new argv
                self.argv.append("")
            
            # quotes or '\'
            elif double_quoted==False and backslashed==False and char=='\'':
                single_quoted=not single_quoted
            elif single_quoted==False and backslashed==False and char=='"':
                double_quoted=not double_quoted
            elif single_quoted==False and backslashed==False and char=='\\':
                backslashed=True

            # write character
            else:
                self.argv[len(self.argv)-1]+=char
                # reset backslash
                backslashed=False

            # record position of cursor
            if self.cursor==i+1:
                cursor=(len(self.argv)-1,len(self.argv[len(self.argv)-1]))

        
        return cursor


    # tab completion
    def tab_complete(self):
        # parse argv
        cursor=self.parse_argv()

        # write and edit commands
        if self.argv[0]=="w" or self.argv[0]=="e":
            # check that cursor is in first argument
            if cursor[0]==1:
                # complete filesystem path
                self.append_text_at_cursor(self.complete_path(self.argv[cursor[0]],cursor[1]))

    # complete filesystem path
    def complete_path(self,base,end):
        paths=glob.glob(glob.escape(base[:end])+"*")
        print(glob.escape(base[:end])+"*", paths)
        if len(paths)==0:
            return ""
        elif len(paths)==1:
            # append '/' to directories
            if os.path.isdir(paths[0]):
                return paths[0][end:]+"/"
            else:
                return paths[0][end:]
        else:
            # display in status bar
            self.app.status_bar.message=""
            for path in paths:
                name=os.path.basename(path)
                # add quotes if needed
                if " " in name:
                    name="\""+name+"\""
                self.app.status_bar.message+=name+" "
            self.app.status_bar.draw()
            return os.path.commonprefix(paths)[end:]


    # run command
    def run_command(self):
        # parse command line
        self.parse_argv()

        # write
        if self.argv[0]=="w" or self.argv[0]=="w!" or self.argv[0]=="wq":
            if len(self.argv)>2:
                self.message="error: could not write to file: too many arguments -- usage: ':w [path to file]'"
                return
            elif len(self.argv)==1:
                if os.path.isfile(self.app.openfile):
                    self.app.painter.write(self.app.openfile)
                else:
                    self.message="error: no file is open for editing, specify a path"
                return
            else:
                # check that the file is not a directory
                if os.path.isdir(self.argv[1]):
                    self.message="error: '"+self.argv[1]+"' is a directory"
                    return
                # check that file does not already exist
                elif self.argv[0]!="w!" and self.argv[1]!= self.app.openfile and os.path.isfile(self.argv[1]):
                    self.message="error: '"+self.argv[1]+"' already exists (use ':w!' to overwrite)"
                    return
                # check that the containing directory exists
                elif len(os.path.dirname(self.argv[1]))>0 and not os.path.isdir(os.path.dirname(self.argv[1])):
                    self.message="error: could not find directory '"+os.path.dirname(self.argv[1])+"'"
                    return
                # check permissions
                elif (len(os.path.dirname(self.argv[1]))>0 and not os.access(os.path.dirname(self.argv[1]),os.W_OK)) or (len(os.path.dirname(self.argv[1]))==0 and not os.access(os.getcwd(),os.W_OK)):
                    self.message="error: permission denied"
                    return
                else:
                    self.app.painter.write(self.argv[1])

        # open file
        if self.argv[0]=="e":
            if len(self.argv)>2:
                self.message="error: could not open file: too many arguments -- usage: ':e <path to file>'"
                return
            elif len(self.argv)==1:
                self.message="error: could not open file: no argument found -- usage: ':e <path to file>'"
                return
            else:
                # check that the file is not a directory
                if os.path.isdir(self.argv[1]):
                    self.message="error: '"+self.argv[1]+"' is a directory"
                    return
                # check that the file exists
                elif not os.path.isfile(self.argv[1]):
                    self.message="error: could not find file '"+self.argv[1]+"'"
                    return
                # check permissions
                elif not os.access(self.argv[1],os.R_OK):
                    self.message="error: permission denied"
                    return
                else:
                    # select openfile
                    self.app.openfile=self.argv[1]
                    # read the file
                    self.app.painter.read(self.argv[1])

        # quit
        if self.argv[0]=="q" or self.argv=="wq":
            self.app.stop()