# -*- coding: utf-8 -*-
"""
/***************************************************************************
 Qgis2threejs
                                 A QGIS plugin
 export terrain data, map canvas image and vector data to web browser
                              -------------------
        begin                : 2014-01-16
        copyright            : (C) 2014 Minoru Akagi
        email                : akaginch@gmail.com
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program 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 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
"""
import struct
from PyQt5.QtCore import QByteArray, QSize
from qgis.core import QgsPoint, QgsProject

from .conf import debug_mode
from .datamanager import MaterialManager
from .exportlayer import LayerExporter
from .geometry import PolygonGeometry, TriangleMesh, Triangles, dissolvePolygonsOnCanvas
from .propertyreader import DEMPropertyReader
from .rotatedrect import RotatedRect


class DEMLayerExporter(LayerExporter):

  def __init__(self, settings, imageManager, layer, pathRoot=None, urlRoot=None, progress=None):
    """if both pathRoot and urlRoot are None, object is built in all_in_dict mode."""
    LayerExporter.__init__(self, settings, imageManager, layer, pathRoot, urlRoot, progress)
    self.provider = settings.demProviderByLayerId(layer.layerId)
    self.prop = DEMPropertyReader(layer.layerId, layer.properties)

  def build(self, export_blocks=False):
    if self.provider is None:
      return None

    d = {
      "type": "layer",
      "id": self.layer.jsLayerId,
      "properties": self.layerProperties()
      }

    if debug_mode:
      d["PROPERTIES"] = self.properties

    # DEM block
    if export_blocks:
      d["data"] = [block.build() for block in self.blocks()]
    else:
      d["data"] = []

    return d

  def layerProperties(self):
    p = LayerExporter.layerProperties(self)
    p["type"] = "dem"
    p["shading"] = self.properties.get("checkBox_Shading", True)
    return p

  def blocks(self):
    mapTo3d = self.settings.mapTo3d()
    baseExtent = self.settings.baseExtent
    center = baseExtent.center()
    rotation = baseExtent.rotation()
    base_grid_size = self.prop.demSize(self.settings.mapSettings.outputSize())

    # clipping
    clip_geometry = None
    clip_option = self.properties.get("checkBox_Clip", False)
    if clip_option:
      clip_layerId = self.properties.get("comboBox_ClipLayer")
      clip_layer = QgsProject.instance().mapLayer(clip_layerId) if clip_layerId else None
      if clip_layer:
        clip_geometry = dissolvePolygonsOnCanvas(self.settings, clip_layer)

    # surroundings
    surroundings = self.properties.get("checkBox_Surroundings", False)    #TODO: [GSIElevProvider] if prop.layerId else False
    roughening = self.properties["spinBox_Roughening"] if surroundings else 1
    size = self.properties["spinBox_Size"] if surroundings else 1
    size2 = size * size

    blks = []
    for i in range(size2):
      sx = i % size - (size - 1) // 2
      sy = i // size - (size - 1) // 2
      dist2 = sx * sx + sy * sy
      blks.append([dist2, i, sx, sy])

    for dist2, blockIndex, sx, sy in sorted(blks):
      #self.progress(20 * i / size2 + 10)
      is_center = (sx == 0 and sy == 0)

      if is_center:
        extent = baseExtent
        grid_size = base_grid_size
      else:
        block_center = QgsPoint(center.x() + sx * baseExtent.width(), center.y() + sy * baseExtent.height())
        extent = RotatedRect(block_center, baseExtent.width(), baseExtent.height()).rotate(rotation, center)
        grid_size = QSize(max(2, (base_grid_size.width() - 1) // roughening + 1),
                          max(2, (base_grid_size.height() - 1) // roughening + 1))

      block = DEMBlockExporter(self.settings,
                               self.imageManager,
                               self.layer,
                               blockIndex,
                               self.provider,
                               grid_size,
                               extent,
                               mapTo3d.planeWidth,
                               mapTo3d.planeHeight,
                               offsetX=mapTo3d.planeWidth * sx,
                               offsetY=mapTo3d.planeHeight * sy,
                               edgeRougheness=roughening if is_center else 1,
                               clip_geometry=clip_geometry if is_center else None,
                               pathRoot=self.pathRoot,
                               urlRoot=self.urlRoot)
      yield block


class DEMBlockExporter:

  def __init__(self, settings, imageManager, layer, blockIndex, provider, grid_size, extent, planeWidth, planeHeight, offsetX=0, offsetY=0, edgeRougheness=1, clip_geometry=None, pathRoot=None, urlRoot=None):
    self.settings = settings
    self.imageManager = imageManager
    self.materialManager = MaterialManager(settings.materialType())

    self.layer = layer
    self.properties = layer.properties

    self.blockIndex = blockIndex
    self.provider = provider
    self.grid_size = grid_size
    self.extent = extent
    self.planeWidth = planeWidth
    self.planeHeight = planeHeight
    self.offsetX = offsetX
    self.offsetY = offsetY
    self.edgeRougheness = edgeRougheness
    self.clip_geometry = clip_geometry
    self.pathRoot = pathRoot
    self.urlRoot = urlRoot

  def build(self):
    if self.edgeRougheness == 1:
      ba = self.provider.read(self.grid_size.width(), self.grid_size.height(), self.extent)
    else:
      grid_values = list(self.provider.readValues(self.grid_size.width(), self.grid_size.height(), self.extent))
      self.processEdges(grid_values, self.edgeRougheness)
      ba = struct.pack("{0}f".format(self.grid_size.width() * self.grid_size.height()), *grid_values)

    # write grid values to an external binary file
    if self.pathRoot is not None:
      with open(self.pathRoot + "{0}.bin".format(self.blockIndex), "wb") as f:
        f.write(ba)

    # block data
    g = {"width": self.grid_size.width(),
         "height": self.grid_size.height()}

    if self.urlRoot is None:
      g["binary"] = QByteArray(ba)
      # g["array"] = grid_values
    else:
      g["url"] = self.urlRoot + "{0}.bin".format(self.blockIndex)

    # material
    material = self.material()

    mapTo3d = self.settings.mapTo3d()
    b = {"type": "block",
         "layer": self.layer.jsLayerId,
         "block": self.blockIndex,
         "grid": g,
         "width": self.planeWidth,
         "height": self.planeHeight,
         "translate": [self.offsetX, self.offsetY, mapTo3d.verticalShift * mapTo3d.multiplierZ],
         "zShift": mapTo3d.verticalShift,
         "zScale": mapTo3d.multiplierZ,
         "material": material}

    # clipped with polygon layer
    if self.clip_geometry:
      b["clip"] = self.clipped()

    # sides and bottom
    if self.properties.get("checkBox_Sides", False):
      b["sides"] = True

    # frame
    if self.properties.get("checkBox_Frame", False) and not self.properties.get("checkBox_Clip", False):
      b["frame"] = True 

    return b

  def material(self):
    # properties
    texture_scale = self.properties.get("comboBox_TextureSize", 100) // 100
    opacity = self.properties.get("spinBox_Opacity", 100) / 100
    transp_background = self.properties.get("checkBox_TransparentBackground", False)

    # display type
    canvas_size = self.settings.mapSettings.outputSize()
    if self.properties.get("radioButton_MapCanvas", False):
      #if texture_scale == 1:
      #  mi = self.materialManager.getCanvasImageIndex(opacity, transp_background)
      #else:
      mi = self.materialManager.getMapImageIndex(canvas_size.width() * texture_scale, canvas_size.height() * texture_scale, self.extent, opacity, transp_background)

    elif self.properties.get("radioButton_LayerImage", False):
      layerids = self.properties.get("layerImageIds", [])
      mi = self.materialManager.getLayerImageIndex(layerids, canvas_size.width() * texture_scale, canvas_size.height() * texture_scale, self.extent, opacity, transp_background)

    elif self.properties.get("radioButton_ImageFile", False):
      filepath = self.properties.get("lineEdit_ImageFile", "")
      mi = self.materialManager.getImageFileIndex(filepath, opacity, transp_background, True)

    else:   #.get("radioButton_SolidColor", False)
      mi = self.materialManager.getMeshMaterialIndex(self.properties.get("colorButton_Color", ""), opacity, True)

    #elif self.properties.get("radioButton_Wireframe", False):
    #  mi = self.materialManager.getWireframeIndex(self.properties["lineEdit_Color"], opacity)

    # build material
    filepath = None if self.pathRoot is None else "{0}{1}.png".format(self.pathRoot, self.blockIndex)
    url = None if self.urlRoot is None else "{0}{1}.png".format(self.urlRoot, self.blockIndex)
    return self.materialManager.build(mi, self.imageManager, filepath, url, self.settings.base64)

  def clipped(self):
    mapTo3d = self.settings.mapTo3d()
    z_func = lambda x, y: 0
    transform_func = lambda x, y, z: mapTo3d.transform(x, y, z)

    # create triangle mesh
    hw = 0.5 * mapTo3d.planeWidth
    hh = 0.5 * mapTo3d.planeHeight
    tmesh = TriangleMesh(-hw, -hh,
                         hw, hh,
                         self.grid_size.width() - 1, self.grid_size.height() - 1)

    # split polygons with triangle mesh
    geom = PolygonGeometry.fromQgsGeometry(self.clip_geometry, z_func, transform_func)
    geom.splitPolygon(tmesh, z_func)

    triangles = Triangles()
    split_polygons = []
    for polygon in geom.split_polygons:
      boundary = polygon[0]
      if len(polygon) == 1 and len(boundary) == 4:
        triangles.addTriangle(boundary[0], boundary[2], boundary[1])    # vertex order should be counter-clockwise
      else:
        bnds = [[[pt.x, pt.y] for pt in bnd] for bnd in polygon]
        split_polygons.append(bnds)

    return {"polygons": geom.asList2(),
            "triangles": {"v": [[pt.x, pt.y] for pt in triangles.vertices],
                          "f": triangles.faces},
            "split_polygons": split_polygons}

  def processEdges(self, grid_values, roughness):
    grid_width = self.grid_size.width()
    grid_height = self.grid_size.height()
    rg_grid_width = (grid_width - 1) // roughness + 1
    rg_grid_height = (grid_height - 1) // roughness + 1
    ii = range(roughness)[1:]

    for x0 in range(rg_grid_width - 1):
      # top edge
      ix0 = x0 * roughness
      z0 = grid_values[ix0]
      z1 = grid_values[ix0 + roughness]
      for i in ii:
        grid_values[ix0 + i] = (z1 - z0) * i / roughness + z0

      # bottom edge
      iy0 = grid_width * (grid_height - 1)
      z0 = grid_values[iy0 + ix0]
      z1 = grid_values[iy0 + ix0 + roughness]
      for i in ii:
        grid_values[iy0 + ix0 + i] = (z1 - z0) * i / roughness + z0

    rw = roughness * grid_width
    for y0 in range(rg_grid_height - 1):
      # left edge
      iy0 = y0 * grid_width
      z0 = grid_values[iy0]
      z1 = grid_values[iy0 + rw]
      for i in ii:
        grid_values[iy0 + i * grid_width] = (z1 - z0) * i / roughness + z0

      # right edge
      iy0 += grid_width - 1
      z0 = grid_values[iy0]
      z1 = grid_values[iy0 + rw]
      for i in ii:
        grid_values[iy0 + i * grid_width] = (z1 - z0) * i / roughness + z0

  def getValue(self, x, y):

    def _getValue(gx, gy):
      return self.grid_values[gx + self.grid_width * gy]

    if 0 <= x and x <= self.grid_width - 1 and 0 <= y and y <= self.grid_height - 1:
      ix, iy = int(x), int(y)
      sx, sy = x - ix, y - iy

      z11 = _getValue(ix, iy)
      z21 = 0 if x == self.grid_width - 1 else _getValue(ix + 1, iy)
      z12 = 0 if y == self.grid_height - 1 else _getValue(ix, iy + 1)
      z22 = 0 if x == self.grid_width - 1 or y == self.grid_height - 1 else _getValue(ix + 1, iy + 1)

      return (1 - sx) * ((1 - sy) * z11 + sy * z12) + sx * ((1 - sy) * z21 + sy * z22)    # bilinear interpolation

    return 0    # as safe null value

  def gridPointToPoint(self, x, y):
    x = self.rect.xMinimum() + self.rect.width() / (self.grid_width - 1) * x
    y = self.rect.yMaximum() - self.rect.height() / (self.grid_height - 1) * y
    return x, y

  def pointToGridPoint(self, x, y):
    x = (x - self.rect.xMinimum()) / self.rect.width() * (self.grid_width - 1)
    y = (self.rect.yMaximum() - y) / self.rect.height() * (self.grid_height - 1)
    return x, y


class DEMBlocks:

  def __init__(self):
    self.blocks = []

  def appendBlock(self, block):
    self.blocks.append(block)

  def appendBlocks(self, blocks):
    self.blocks += blocks

  def processEdges(self):
    """for now, this function is designed for simple resampling mode with surroundings"""
    count = len(self.blocks)
    if count < 9:
      return

    ci = (count - 1) // 2
    size = int(count ** 0.5)

    center = self.blocks[0]
    blocks = self.blocks[1:ci + 1] + [center] + self.blocks[ci + 1:]

    grid_width, grid_height, grid_values = center.grid_width, center.grid_height, center.grid_values
    for istop, neighbor in enumerate([blocks[ci - size], blocks[ci + size]]):
      if grid_width == neighbor.grid_width:
        continue

      y = grid_height - 1 if not istop else 0
      for x in range(grid_width):
        gx, gy = center.gridPointToPoint(x, y)
        gx, gy = neighbor.pointToGridPoint(gx, gy)
        grid_values[x + grid_width * y] = neighbor.getValue(gx, gy)

    for isright, neighbor in enumerate([blocks[ci - 1], blocks[ci + 1]]):
      if grid_height == neighbor.grid_height:
        continue

      x = grid_width - 1 if isright else 0
      for y in range(grid_height):
        gx, gy = center.gridPointToPoint(x, y)
        gx, gy = neighbor.pointToGridPoint(gx, gy)
        grid_values[x + grid_width * y] = neighbor.getValue(gx, gy)

  def stats(self):
    if len(self.blocks) == 0:
      return {"max": 0, "min": 0}

    block = self.blocks[0]
    stats = {"max": block.orig_stats["max"], "min": block.orig_stats["min"]}
    for block in self.blocks[1:]:
      stats["max"] = max(block.orig_stats["max"], stats["max"])
      stats["min"] = min(block.orig_stats["min"], stats["min"])
    return stats


def dummyProgress(progress=None, statusMsg=None):
  pass