# Friday, February 5, 2021

"""
**coordinate_generator.py**

A module that will contain the functions and classes associated with generating x,y coordinates
"""

from .fileio import create_dir_if_not, export_dict
import matplotlib.pyplot as plt
import pandas as pd


class CoordinateGeneratorBase:
    """
    This is a child (base) class to all of the coordinate generation techniques.
    """
    def __init__(self):
        self.coordinates = {}

    def visualize_coordinates(self, path_to_output=None, plot_ext='pdf'):
        if path_to_output is None:
            path_to_output = 'Plots/'
        create_dir_if_not(path_to_output)

        for key in self.coordinates:
            fig, ax = self.plot_coordinates(key)
            fig.savefig(path_to_output + key + '.' + plot_ext)
            plt.close(fig)

    def plot_coordinates(self, key: str):
        """
        Plot x, y coordinates based on the key provided. This key must correspond to values in self.coordinates.

        Parameters
        ----------
        key: str
            A hash key for the dictionary self.coordinates

        Returns
        -------
        fig, ax
            The figure and axes associated with the borefield layout plot.

        """

        current_coordinates = self.coordinates[key]
        x, y = list(zip(*current_coordinates))

        fig, ax = plt.subplots()

        ax.scatter(x, y)
        # https://stackoverflow.com/a/41200561/11637415
        ax.axis('scaled')

        ax.set_xlabel('x (m)')
        ax.set_ylabel('y (m)')

        fig.tight_layout()

        return fig, ax

    def export_coordinates(self, path_to_output=None, file_ext='csv'):
        if path_to_output is None:
            path_to_output = 'CSVs/'
        create_dir_if_not(path_to_output)

        for key in self.coordinates:
            current_coordinates = self.coordinates[key]
            x, y = list(zip(*current_coordinates))
            # create dictionary for exporting the coordinates
            d_out: dict = {'x': x, 'y': y}
            output_path: str = path_to_output + key + '.' + file_ext
            export_dict(d_out, output_path, file_ext)


class ZonedRectangle(CoordinateGeneratorBase):
    """
        A class for control of zoned rectangles.

        Original implementation by <NAME> in VBA.

        Parameters
        ----------
        Nx: int
            Number of boreholes on perimeter in x direction
        Ny: int
            Number of boreholes on perimeter in y direction
        B: float
            Spacing of perimeter boreholes (m)
        Nix: int, optional
            Number of interior borehole in the x direction Nix < (Nx-2);
            if Nix=Nx-2 that would be a regular uniform rectangle
        Niy: int, optional
            Number of interior boreholes in the y direction Niy < (Ny-2);
            if Niy=Ny-2, that would be a regular uniform rectangle

            .. note::
                Assumptions/Limitations/Comments:

                1. We assume on the perimeter uniform spacing; the same in both directions.
                2. The interior spacing in each direction if uniform (but may be different in
                the x and y directions). It is set, so that in each direction, the spacing
                between the interior boreholes is the same as the spacing from the outermost
                interior borehole and the perimeter. Interior boreholes are not usually aligned
                with the perimeter boreholes.

        Raises
        --------
        ValueError
            if the optional Nix is provided and `Nix > (Nx-2)`
            if the optional Niy is provided and `Niy > (Ny-2)`


    """
    def __init__(self, Nx: int, Ny: int, B: float, Nix: int = None, Niy: int = None):
        super().__init__()  # initialize the base class
        # keep in mind that self. now has everything that is in the __init__ of CoordinateGeneratorBase
        self.Nx = Nx
        self.Ny = Ny
        self.B = B
        if Nix is None:
            self.Nix = Nx - 2
        else:
            if Nix > (Nx-2):
                raise ValueError('To many interior x boreholes.')
        if Niy is None:
            self.Niy = Ny - 2
        else:
            if Niy > (Ny-2):
                raise ValueError('Too many interior y boreholes.')
        if Nix is None and Niy is None:
            self.z_rect_control()  # generate all of the zoned rectangles

    def coordinate(self, i: int, j: int):
        """
        Given and i and a j value, return the x and y coordinate based on the equal B spacing in the field.

        Parameters
        ----------
        i: int
            the iterator i in a for loop, corresponding to the x-coordinate
        j: int
            the iterator j in a for loop, corresponding to the y-coordinate

        Returns
        -------
        (x, y): tuple
            A tuple containing the x and y coordinate for this i and j
        """
        x = (i - 1) * self.B
        y = (j - 1) * self.B
        return x, y

    def hash_key(self):
        """
        This function will query the self for Nx, Ny, Nix and Niy values

        Returns
        -------
        key: str
            '<KEY>'
        """
        key = 'ZRect_' + str(self.Nx) + '_x_' + str(self.Ny) + '_' + str(self.Nix) + '_x_' + str(self.Niy)
        return key

    def gen_z_rect(self):
        key = self.hash_key()
        # Create a list of (x, y) coordinates
        current_coordinates = []

        # 1) Create the top and bottom rows
        for i in range(1, self.Nx+1):
            # create bottom row
            j = 1
            x, y = self.coordinate(i, j)
            current_coordinates.append((x, y))
            # create top row
            j = self.Ny
            x, y = self.coordinate(i, j)
            current_coordinates.append((x, y))

        # 2) Create the left and right columns, excluding the corners
        for j in range(2, self.Ny):
            # create the left column
            i = 1
            x, y = self.coordinate(i, j)
            current_coordinates.append((x, y))
            # create the right column
            i = self.Nx
            x, y = self.coordinate(i, j)
            current_coordinates.append((x, y))

        # 3) Create the interior coordinates
        Bx = (self.Nx - 1) * self.B / (self.Nix + 1)
        By = (self.Ny - 1) * self.B / (self.Niy + 1)

        for i in range(1, self.Nix+1):
            for j in range(1, self.Niy+1):
                x = i * Bx
                y = j * By
                current_coordinates.append((x, y))
        self.coordinates[key] = current_coordinates

    def reduce_i_rect(self):
        """
        Determines the internal rectangle row or column reduction
        that keeps the x and y spacing the most uniform, and updates
        the correct new value of Nix and Niy in self.

        Returns
        -------
        finished: bool
            This method will return a true or false value. If the value is false, continue creating rectangles,
            if it is true then no more zoned rectangles can be generated.
        """
        finished = False
        # tentative values
        Nixm1 = self.Nix - 1
        Niym1 = self.Niy - 1

        if Nixm1 == 0 and Niym1 == 0:
            finished = True  # no further reductions can be made
        elif Nixm1 == 0:
            self.Niy = Niym1  # reduce in the y-direction
            if self.Niy == 1:
                finished = True
        elif Niym1 == 0:
            self.Nix = Nixm1
            if self.Nix == 1:
                finished = True
        else:
            # general case where we can reduce in either direction
            x_spacing_c = (self.Nx - 1) * self.B / (self.Nix + 1)  # current x spacing
            y_spacing_c = (self.Ny - 1) * self.B / (self.Niy + 1)  # current y spacing
            x_spacing_t = (self.Nx - 1) * self.B / self.Nix  # x spacing if we reduce one column
            y_spacing_t = (self.Ny - 1) * self.B / self.Niy  # y spacing if we reduce one row

            # possible outcomes
            f_x = x_spacing_t / y_spacing_c  # ratio (fraction) if we reduce one column
            if f_x < 1:
                f_x = 1 / f_x
            f_y = x_spacing_c / y_spacing_t  # ratio (fraction) if we reduce one row
            if f_y < 1:
                f_y = 1 / f_y
            d_f_x = f_x - 1  # distance of ratio from 1 if we reduce one column
            d_f_y = f_y - 1  # distance of ratio from 1 if wer reduce one row
            if d_f_x > d_f_y:
                self.Niy = Niym1
            else:
                self.Nix = Nixm1

        return finished

    def z_rect_control(self):
        """
        This function is called if the optional inputs Nix and Niy are not provided. This will
        create all of the zoned rectangles given Nx, Ny and B. A while loop continuously calls
        :func:`gFunctionLibrary.coordinate_generator.ZonedRectangle.reduce_i_rect` until all of
        the zoned rectangles have been created.

        Returns
        -------
        None
            The coordinates are stored in self.coordinates(), an instance of
            :func:`gFunctionLibrary.coordinate_generator.CoordinateGeneratorBase` made available
            because Base is a child.

        """
        # while we are still able to create more zoned rectangles, create zoned rectangles
        # self.gen_z_rect()  # if this was not commented out then we would create the square first
        unfinished: bool = True
        while unfinished:
            finished: bool = self.reduce_i_rect()
            self.gen_z_rect()
            if finished is True:
                unfinished = False
