#    Copyright 2020 Romain de Laage
#
#    This file is part of tkGemini.
#
#    tkGemini is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    any later version.
#
#    tkGemini is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with tkGemini.  If not, see <https://www.gnu.org/licenses/>.

import tkinter as tk
import tkinter.font as tkFont

# Renderer class to transform a Gemini text into a visual text formatted
class Renderer():
    def __init__(self, parent, text):
        # Some global variable
        self.parent = parent
        self.text = text
        self.currX = 0
        self.currY = 1
        self.content = tk.Text(self.parent.root)

        # Definition for some styles
        self.h1Font = tkFont.Font(weight="bold", size="26")
        self.content.tag_config("h1", font=self.h1Font)
        self.h2Font = tkFont.Font(weight="bold", size="20")
        self.content.tag_config("h2", font=self.h2Font)
        self.h3Font = tkFont.Font(weight="bold", size="16")
        self.content.tag_config("h3", font=self.h3Font)
        self.underlineFont = tkFont.Font(underline=1)

    def addNormalText(self, text):
        # Draw normal text on the current line and go to the next line
        self.content.insert(str(self.currY)+'.'+str(self.currX), text+"\n")
        self.currY+=1

    def addLink(self, text, url):
        # Calculate current index (position)
        index1 = str(self.currY)+'.'+str(self.currX)

        #prepare tag for this link (format + action when clicking)
        self.content.tag_config("link-"+index1, foreground="#00f", font=self.underlineFont)
        self.content.tag_bind("link-"+index1, "<Button-1>", lambda event, url=url, parent=self.parent:
                parent.linkClick(url))

        # Add text, add tag from the beginning to the end and go to a new line
        self.content.insert(index1, text+"\n")
        self.content.tag_add("link-"+index1, index1, str(self.currY)+'.'+str(self.currX+len(text)))
        self.currY+=1

    def addHeading1(self, text):
        # Calculate current index
        index1 = str(self.currY)+'.'+str(self.currX)

        # Insert text then apply tag and go to a new line
        self.content.insert(index1, text+"\n")
        self.content.tag_add("h1", index1, str(self.currY)+'.'+str(self.currX+len(text)))
        self.currY+=1

    def addHeading2(self, text):
        # Calculate current index
        index1 = str(self.currY)+'.'+str(self.currX)

        # Insert text then apply tag and go to a new line
        self.content.insert(index1, text+"\n")
        self.content.tag_add("h2", index1, str(self.currY)+'.'+str(self.currX+len(text)))
        self.currY+=1

    def addHeading3(self, text):
        # Calculate current index
        index1 = str(self.currY)+'.'+str(self.currX)

        # Inset text then apply tag and go to a new line
        self.content.insert(index1, text+"\n")
        self.content.tag_add("h3", index1, str(self.currY)+'.'+str(self.currX+len(text)))
        self.currY+=1

    def addListItem(self, text):
        # Same as drawing a normal line but with a tab and a bullet point at the beginning
        self.content.insert(str(self.currY)+'.'+str(self.currX), "\t• "+text+"\n")
        self.currY+=1

    def parse(self):
        # Make text editable
        self.content['state'] = 'normal'

        # Reinitialize position
        self.currY=1
        self.currX=0

        # Delete all the current text
        self.content.delete("1.0", tk.END)

        # Cut the text into line
        lines = self.text.split("\n")

        # Parse each line
        for line in lines:
            if(line.startswith("###")):
                self.addHeading3(line[3:].strip())
            elif(line.startswith("##")):
                self.addHeading2(line[2:].strip())
            elif(line.startswith("#")):
                self.addHeading1(line[1:].strip())
            elif(line.startswith("*")):
                self.addListItem(line[1:].strip())
            elif(line.startswith("=>")):
                line = line[2:].strip()

                # Link location is before the first whitespace
                url = line.split()[0]

                # Link text is after the first whitespace
                text = line[len(url):len(line)].strip()

                # If there is no text, then the link location become the text
                if text == "":
                    text = url

                self.addLink(text, url)
            else:
                self.addNormalText(line)

        # Now the text should not be edited
        self.content['state'] = 'disabled'