# SPDX-FileCopyrightText: ☭ Emery Hemingway
# SPDX-License-Identifier: Unlicense

import std/[deques]
import pixie

type
  Pane* = ref object
    image: pixie.Image
    spans: seq[Span]
    arrangement: Arrangement

  Well* = ref object
    panes: Deque[Pane]

proc newFrame(width, height: int): Frame =
  let (w, h) = (width div 2, height div 2)
  new result
  result.panes[0] = Pane(image: newImage(w, h))
  result.panes[1] = Pane(image: newImage(w, h))
  result.panes[2] = Pane(image: newImage(w, h))

proc paneVec2(frame: Frame): Vec2 =
  vec2(frame.panes[0].image.width.float32, frame.panes[0].image.height.float32)

proc allocChild(frame: Frame) =
  assert frame.child.isNil
  let (w, h) = (frame.panes[0].image.width div 2, frame.panes[0].image.height div 2)
  doAssert w > 2 and h > 2, $w & "x" & $h
  frame.child = newFrame(w, h)

proc setDepth(frame: Frame; n: Natural) =
  var
    frame = frame
    i = n
  while i > 0:
    dec(i)
    if frame.child.isNil:
      allocChild(frame)
    frame = frame.child

proc `[]`*(frame: Frame; i: Natural): Pane =
  var
    frame = frame
    i = i
  while true:
    if i < 4:
      return frame.panes[i]
    if frame.child.isNil:
      allocChild(frame)
    frame = frame.child
    dec(i, 4)

iterator walkPanes(frame: Frame): tuple[coord: Vec2, pane: Pane] =
  var frame = frame
  while not frame.isNil and
      frame.panes[0].image.width > 2 and
      frame.panes[1].image.height > 2:
    let coord = frame.paneVec2
    yield(coord, frame.panes[0])
    yield(coord - vec2(coord.x, 0), frame.panes[1])
    yield(coord - vec2(0, coord.y), frame.panes[2])
    frame = frame.child

proc append*(frame: Fram; text: string; font: Font) =
  let span = newSpan(text, font)

proc append*(frame: Fram; stream: Stream; font: Font) =
  var line: string
  while readLine(stream, line):
    append(frame, font, line)

when isMainModule:
  let frame = newFrame(800, 600)
  frame.setDepth(3)
  for (coord, pane) in walkPanes(frame):
    echo coord, " - ", pane.image.width, "x", pane.image.height