
from copy import deepcopy
from math import ceil, floor
from collections import namedtuple

from qgis.core import QgsMessageLog
from qgis.core import Qgis

from .projections import *
from .points import *
from .project import *


raster_parameters_fields = [
    'name',
    'cellsizeEW',
    'cellsizeNS',
    'rows',
    'cols',
    'xMin',
    'xMax',
    'yMin',
    'yMax',
    'nodatavalue',
    'crs'
]

RasterParameters = namedtuple(
    'RasterParameters',
    raster_parameters_fields
)


class QGisRasterParameters(object):

    def __init__(self,
                 name,
                 cellsizeEW,
                 cellsizeNS,
                 rows,
                 cols,
                 xMin,
                 xMax,
                 yMin,
                 yMax,
                 nodatavalue,
                 crs
                 ):

        self.name = name
        self.cellsizeEW = cellsizeEW
        self.cellsizeNS = cellsizeNS
        self.rows = rows
        self.cols = cols
        self.xMin = xMin
        self.xMax = xMax
        self.yMin = yMin
        self.yMax = yMax
        self.nodatavalue = nodatavalue
        self.crs = crs

    def point_in_dem_area(self,
                          point
                          ):
        """
        Check that a point is within or on the boundary of the grid area.
        Assume grid has no rotation.

        :return: bool
        """

        if self.xMin <= point.x <= self.xMax and \
                self.yMin <= point.y <= self.yMax:
            return True
        else:
            return False

    def point_in_interpolation_area(self,
                                    point
                                    ):
        """
        Check that a point is within or on the boundary of the area defined by
        the extreme cell center values.
        Assume grid has no rotation.

        :return: bool
        """

        if self.xMin + self.cellsizeEW / 2.0 <= point.x <= self.xMax - self.cellsizeEW / 2.0 and \
                self.yMin + self.cellsizeNS / 2.0 <= point.y <= self.yMax - self.cellsizeNS / 2.0:
            return True
        else:
            return False

    def geogr2raster(self,
                     point
                     ):
        """
        Convert from geographic to raster-based coordinates.
        Assume grid has no rotation.

        :return: dict
        """

        x = (point.x - (self.xMin + self.cellsizeEW / 2.0)) / self.cellsizeEW
        y = (point.y - (self.yMin + self.cellsizeNS / 2.0)) / self.cellsizeNS

        return dict(x=x, y=y)

    def raster2geogr(self,
         array_dict
         ) -> Point:
        """
        Convert from raster-based to geographic coordinates.
        Assume grid has no rotation.

        :param array_dict: dict
        :return: the point in geographic planar coordinates
        """

        assert 'x' in array_dict
        assert 'y' in array_dict

        x = self.xMin + (array_dict['x'] + 0.5) * self.cellsizeEW
        y = self.yMin + (array_dict['y'] + 0.5) * self.cellsizeNS

        return Point(x, y)


def get_z(
    dem_layer,
    point
) -> Union[None, numbers.Real]:

    try:

        identification = dem_layer.dataProvider().identify(QgsPointXY(point.x, point.y), QgsRaster.IdentifyFormatValue)

        if not identification.isValid():
            raise Exception(f"Point identification within DEM was unsuccessful")

        result_map = identification.results()
        return float(result_map[1])

    except Exception as e:

        QgsMessageLog.logMessage(
            f"Error in get_z: {e!r}",
            "qgSurf",
            Qgis.MessageLevel.Warning
        )
        return None


def get_zs_from_dem(
    struct_pts_2d,
    demObj
):

    z_list = []
    for point_2d in struct_pts_2d:
        interp_z = interpolate_z(demObj.layer, demObj.params, point_2d)
        z_list.append(interp_z)

    return z_list


def interpolate_bilinear(
    dem: QgsRasterLayer,
    qrpDemParams: QGisRasterParameters,
    point: Point
) -> Union[None, numbers.Real]:

    try:

        dArrayCoords = qrpDemParams.geogr2raster(point)

        floor_x_raster = floor(dArrayCoords["x"])
        ceil_x_raster = ceil(dArrayCoords["x"])
        floor_y_raster = floor(dArrayCoords["y"])
        ceil_y_raster = ceil(dArrayCoords["y"])

        # bottom-left center
        p1 = qrpDemParams.raster2geogr(dict(x=floor_x_raster,
                                            y=floor_y_raster))
        # bottom-right center
        p2 = qrpDemParams.raster2geogr(dict(x=ceil_x_raster,
                                            y=floor_y_raster))
        # top-left center
        p3 = qrpDemParams.raster2geogr(dict(x=floor_x_raster,
                                            y=ceil_y_raster))
        # top-right center
        p4 = qrpDemParams.raster2geogr(dict(x=ceil_x_raster,
                                            y=ceil_y_raster))

        z1 = get_z(dem, p1)
        if z1 is None:
            raise Exception("z1 is None")
        z2 = get_z(dem, p2)
        if z2 is None:
            raise Exception("z2 is None")
        z3 = get_z(dem, p3)
        if z3 is None:
            raise Exception("z3 is None")
        z4 = get_z(dem, p4)
        if z4 is None:
            raise Exception("z4 is None")

        delta_x = point.x - p1.x
        delta_y = point.y - p1.y

        z_x_a = z1 + (z2 - z1) * delta_x / qrpDemParams.cellsizeEW
        z_x_b = z3 + (z4 - z3) * delta_x / qrpDemParams.cellsizeEW

        z = z_x_a + (z_x_b - z_x_a) * delta_y / qrpDemParams.cellsizeNS

        return z

    except Exception as e:

        QgsMessageLog.logMessage(
            f"Error in get_z: {e!r}",
            "qgSurf",
            Qgis.MessageLevel.Warning
        )
        return None


def interpolate_z(
    qgs_raster_layer: QgsRasterLayer,
    qgis_raster_parameters: QGisRasterParameters,
    point2d: Point
) -> Tuple[Union[None, numbers.Real], Error]:

    try:

        if qgis_raster_parameters.point_in_interpolation_area(point2d):

            result = interpolate_bilinear(
                qgs_raster_layer,
                qgis_raster_parameters,
                point2d
            )

        elif qgis_raster_parameters.point_in_dem_area(point2d):

            result = get_z(
                qgs_raster_layer,
                point2d)

        else:

            result = None

        return result

    except Exception as e:

        QgsMessageLog.logMessage(
            f"Error in get_z: {e!r}",
            "qgSurf",
            Qgis.MessageLevel.Warning
        )
        return None


def extract_dem_parameters_from_qgs_raster_layer(
    raster_layer: 'qgis.core.QgsRasterLayer',
) -> Union[None, QGisRasterParameters]:

    try:

        name = raster_layer.name()

        rows = raster_layer.height()
        cols = raster_layer.width()

        extent = raster_layer.extent()

        xMin = extent.xMinimum()
        xMax = extent.xMaximum()
        yMin = extent.yMinimum()
        yMax = extent.yMaximum()

        cellsizeEW = (xMax - xMin) / float(cols)
        cellsizeNS = (yMax - yMin) / float(rows)

        # TODO: get real no data value from QGIS
        if raster_layer.dataProvider().sourceHasNoDataValue(1):
            nodatavalue = raster_layer.dataProvider().sourceNoDataValue(1)
        else:
            nodatavalue = np.nan

        try:
            crs = raster_layer.crs()
        except:
            crs = None

        return QGisRasterParameters(
            name,
            cellsizeEW,
            cellsizeNS,
            rows,
            cols,
            xMin,
            xMax,
            yMin,
            yMax,
            nodatavalue,
            crs
        )

    except Exception as e:
        import traceback
        from geogst.core.utils.errors import Error
        from geogst.core.utils.strings import caller_name
        
        err = Error(
            True,
            caller_name(),
            e,
            traceback.format_exc()
        )
        msg = f"Error with {raster_layer.name()} as source: {err!r} "
        warn_qgis(
            "qgSurf",
            msg
        )

        return None

'''
def raster_qgis_params(
        raster_layer
):
    """
    Deprecated: use 'try_extract_raster_qgis_params'
    """

    name = raster_layer.name()

    rows = raster_layer.height()
    cols = raster_layer.width()

    extent = raster_layer.extent()

    xMin = extent.xMinimum()
    xMax = extent.xMaximum()
    yMin = extent.yMinimum()
    yMax = extent.yMaximum()

    cellsizeEW = (xMax - xMin) / float(cols)
    cellsizeNS = (yMax - yMin) / float(rows)

    # TODO: get real no data value from QGIS
    if raster_layer.dataProvider().sourceHasNoDataValue(1):
        nodatavalue = raster_layer.dataProvider().sourceNoDataValue(1)
    else:
        nodatavalue = np.nan

    try:
        crs = raster_layer.crs()
    except:
        crs = None

    return name, cellsizeEW, cellsizeNS, rows, cols, xMin, xMax, yMin, yMax, nodatavalue, crs
'''

def get_dem_resolution_in_prj_crs(
        dem,
        dem_params,
        prj_crs
) -> numbers.Integral:

    cellsizeEW, cellsizeNS = dem_params.cellsizeEW, dem_params.cellsizeNS
    xMin, yMin = dem_params.xMin, dem_params.yMin

    if dem.crs() != prj_crs:
        cellsizeEW_prj_crs = distance_projected_pts(
            xMin,
            yMin,
            cellsizeEW,
            0,
            dem.crs(),
            prj_crs
        )
        cellsizeNS_prj_crs = distance_projected_pts(
            xMin,
            yMin,
            0,
            cellsizeNS,
            dem.crs(),
            prj_crs
        )
    else:
        cellsizeEW_prj_crs = cellsizeEW
        cellsizeNS_prj_crs = cellsizeNS

    return 0.5 * (cellsizeEW_prj_crs + cellsizeNS_prj_crs)


def get_min_dems_resolution(
    selected_dems: List,
    selected_dem_parameters: List
) -> numbers.Real:

    dem_resolutions_prj_crs_list = []

    for dem, dem_params in zip(selected_dems, selected_dem_parameters):
        dem_resolutions_prj_crs_list.append(
            get_dem_resolution_in_prj_crs(
                dem,
                dem_params,
                extract_crs_of_project())
        )

    min_dem_resolution = np.nanmin(dem_resolutions_prj_crs_list)

    if min_dem_resolution > 1:
        sample_distance = round(min_dem_resolution)
    else:
        sample_distance = min_dem_resolution

    return sample_distance


def get_min_dem_resolution(
    selected_dem,
    selected_dem_parameters
) -> numbers.Real:

    dem_resolution = get_dem_resolution_in_prj_crs(
        selected_dem,
        selected_dem_parameters,
        extract_crs_of_project())

    if dem_resolution > 1:
        sample_distance = round(dem_resolution)
    else:
        sample_distance = dem_resolution

    return sample_distance


def calculate_projected_3d_pts(
    struct_pts,
    structural_pts_crs,
    demObj
):

    demCrs = demObj.params.crs

    # check if on-the-fly-projection is set on
    project_crs = extract_crs_of_project()

    # set points in the project crs
    if structural_pts_crs != project_crs:
        struct_pts_in_prj_crs = calculate_pts_in_projection(struct_pts, structural_pts_crs, project_crs)
    else:
        struct_pts_in_prj_crs = deepcopy(struct_pts)

        # project the source points from point layer crs to DEM crs
    # if the two crs are different
    if structural_pts_crs != demCrs:
        struct_pts_in_dem_crs = calculate_pts_in_projection(struct_pts, structural_pts_crs, demCrs)
    else:
        struct_pts_in_dem_crs = deepcopy(struct_pts)

        # - 3D structural points, with x, y, and z extracted from the current DEM
    struct_pts_z = get_zs_from_dem(struct_pts_in_dem_crs, demObj)

    assert len(struct_pts_in_prj_crs) == len(struct_pts_z)

    return [Point(pt.x, pt.y, z) for (pt, z) in zip(struct_pts_in_prj_crs, struct_pts_z)]


def sample_qgsrasterlayer(
    src_line2d: Ln,
    qgs_raster_layer: QgsRasterLayer,
    qgis_raster_parameters: QGisRasterParameters
) -> Tuple[Union[None, Ln], Error]:

    try:

        project_crs = extract_crs_of_project()

        if qgs_raster_layer.crs() != extract_crs_of_project():

            line2d_in_dem_crs = project_line_2d(
                src_line_2d=src_line2d,
                src_crs=project_crs,
                dest_crs=qgs_raster_layer.crs()
            )

            if line2d_in_dem_crs is None:
                return None, Error(
                    True,
                    caller_name(),
                    Exception(f"Line 2D in DEM projection failed"),
                    traceback.format_exc(),
                )

        else:

            line2d_in_dem_crs = src_line2d

        line2d_in_dem_crs_pts = line2d_in_dem_crs.pts()

        src_line2d_pts = src_line2d.pts()

        coords = []

        for point2d_dem_crs, point2d_project_crs in zip(line2d_in_dem_crs_pts, src_line2d_pts):

            result, err = interpolate_z(
                qgs_raster_layer=qgs_raster_layer,
                qgis_raster_parameters=qgis_raster_parameters,
                point2d=point2d_dem_crs
            )

            if err:
                return None, err
            else:
                interpolated_z = result

            x = point2d_project_crs.x
            y = point2d_project_crs.y
            z = interpolated_z

            if not (math.isfinite(x) and math.isfinite(y)):
                return None, Error(
                    True,
                    caller_name(),
                    Exception(f"Non-finite planar coordinates: {x}-{y}"),
                    traceback.format_exc()
                )

            coords.append([x, y, z])

        line_3d = Ln(coords)

        return line_3d, Error()

    except Exception as e:

        return None, Error(
            True,
            caller_name(),
            e,
            traceback.format_exc()
        )
