from fide import *

def cursor_go_left():
    buf = ctx.current_buffer
    cursor = ctx.current_buffer.cursor
    if cursor.col == 0:
        if cursor.line_num > 0:
            cursor.col = buf.lines[cursor.line_num-1].length
            cursor.want_col = cursor.col
            cursor.line_num -= 1
    else:
        cursor.col = max(0, cursor.col - 1)
        cursor.want_col = cursor.col

def cursor_go_right():
    buf = ctx.current_buffer
    cursor = ctx.current_buffer.cursor
    if cursor.col == buffer_line_len(buf):
        if cursor.line_num < buffer_total_lines(buf) - 1:
            cursor.col = 0
            cursor.want_col = cursor.col
            cursor.line_num += 1
    else:
        cursor.col = min(buffer_line_len(buf), cursor.col + 1)
        cursor.want_col = cursor.col

def cursor_go_down():
    buf = ctx.current_buffer
    cursor = ctx.current_buffer.cursor
    if cursor.line_num == len(buf.lines):
        return
    cursor.line_num = min(len(buf.lines) - 1, cursor.line_num + 1)
    line_len = buf.lines[cursor.line_num].length
    cursor.col = min(cursor.want_col, line_len)

def cursor_go_up():
    buf = ctx.current_buffer
    cursor = ctx.current_buffer.cursor
    if cursor.line_num == 0:
        return
    cursor.line_num = max(0, cursor.line_num - 1)
    line_len = buf.lines[cursor.line_num].length
    # TODO: This should be global
    cursor.col = min(cursor.want_col, line_len)

def cursor_go_line_beginning():
    buf = ctx.current_buffer
    buf.cursor.col = 0
    buf.cursor.want_col = buf.cursor.col

def cursor_go_line_end():
    buf = ctx.current_buffer
    buf.cursor.col = buffer_line_len(buf)
    buf.cursor.want_col = buf.cursor.col

def buffer_insert_line_below(buf: Buffer, text):
    line_num = buffer_line_num(buf)
    buf.lines.insert(line_num + 1, line_create(text))

def buffer_newline_at_pos():
    buf = ctx.current_buffer
    curr_line = buffer_line_current(buf)
    cursor = buf.cursor
    if cursor.col < buffer_line_len(buf):
        remainder = curr_line.length - cursor.col
        line = curr_line.piece.string_at(cursor.col, remainder)
        curr_line.piece.delete(cursor.col, remainder)
        curr_line.length -= remainder
    else:
        line = ""
    buffer_insert_line_below(buf, line)
    cursor.line_num += 1
    # Eventually when we need to be indentation aware
    cursor.col = 0
    cursor.want_col = 0


def buffer_delete_character_under_cursor():
    buf = ctx.current_buffer
    cursor = buf.cursor
    if cursor_pos(cursor) != (0,0):
        if cursor.col == 0:
            curr_line = buf.lines.pop(cursor.line_num)
            cursor.line_num -= 1
            above_row = buf.lines[cursor.line_num]
            above_row.piece.insert(curr_line.piece.get_text(), above_row.length)
            cursor.col = above_row.length
            cursor.want_col = cursor.col
            above_row.length += curr_line.length
        else:
            curr_line = buffer_line_current(buf)
            curr_line.piece.delete(cursor.col - 1, 1)
            curr_line.length -= 1
            cursor.col = max(0, cursor.col - 1)
            cursor.want_col = cursor.col

def buffer_delete_next_character():
    buf = ctx.current_buffer
    cursor = buf.cursor
    curr_line = buffer_line_current(buf)
    if cursor.col >= buffer_line_len(buf):
        if cursor.line_num < len(buf.lines) - 1:
            below_row = buf.lines.pop(cursor.line_num+1)
            if below_row.length > 0:
                curr_line.piece.insert(below_row.piece.get_text(), curr_line.length)
                curr_line.length += below_row.length
            cursor.want_col = cursor.col
    else:
        if curr_line.length >= 1:
            curr_line.piece.delete(cursor.col, 1)
            curr_line.length -= 1
            cursor.want_col = cursor.col

def buffer_insert_char(c):
    cursor = ctx.current_buffer.cursor
    curr_line = buffer_line_current(ctx.current_buffer)
    curr_line.piece.insert(c, cursor.col)
    curr_line.length += 1
    cursor.col += 1
    cursor.want_col = cursor.col

def buffer_insert_text_at_cursor(text):
    cursor = ctx.current_buffer.cursor
    curr_line = buffer_line_current(ctx.current_buffer)
    curr_line.piece.insert(text, cursor.col)
    text_len = len(text)
    curr_line.length += text_len
    cursor.col += text_len
    cursor.want_col = text_len