#!/usr/bin/python
import os
import curses
from core import colors, cursor
from modes import normal


def start_screen(stdscr):
    # Get window height and width
    height, width = stdscr.getmaxyx()

    # Startup text
    title = "λ Lambda"
    subtext = [
        "A performant, efficient and hackable text editor",
        "",
        "Type :h to open the README.md document",
        "Type :o <file> to open a file and edit",
        "Type :q or <C-c> to quit lambda"
    ]

    # Centering calculations
    start_x_title = int((width // 2) - (len(title) // 2) - len(title) % 2)
    start_y = int((height // 2) - 2)

    # Rendering title
    stdscr.addstr(start_y, start_x_title, title, curses.color_pair(7) | curses.A_BOLD)

    # Print the subtext
    for text in subtext:
        start_y += 1
        start_x = int((width // 2) - (len(text) // 2) - len(text) % 2)
        stdscr.addstr(start_y, start_x, text)


def start(stdscr):
    # Initialise data before starting
    data = {"cursor_y": 0, "cursor_x": 0, "commands": []}

    # Clear and refresh the screen for a blank canvas
    stdscr.clear()
    stdscr.refresh()

    # Initialise colors
    colors.init_colors()

    # Load the start screen
    start_screen(stdscr)

    # Change the cursor shape
    cursor.cursor_mode("block")

    # Main loop
    while True:
        # Get the height and width of the screen
        height, width = stdscr.getmaxyx()

        # Activate normal mode
        data = normal.activate(stdscr, height, width, data)

        # Calculate a valid cursor position from data
        cursor_x = max(2, data["cursor_x"])
        cursor_x = min(width - 1, cursor_x)
        cursor_y = max(0, data["cursor_y"])
        cursor_y = min(height - 3, cursor_y)

        # Move the cursor
        stdscr.move(cursor_y, cursor_x)

        # Refresh and clear the screen
        stdscr.refresh()
        stdscr.clear()


def main():
    # Change the escape delay to 25ms
    # Fixes an issue where esc takes too long to press
    os.environ.setdefault("ESCDELAY", "25")

    # Initialise the screen
    curses.wrapper(start)


if __name__ == "__main__":
    main()