import ctypes as ct

from floatimg.settings import LIB

############################################################################################################
# type constants
GRAY = 1
RGB = 3
RGBA = 4
RGBZ = 99

############################################################################################################
# Type mapping
class C_FloatImg(ct.Structure):
    """mapping to the C structure of FloatImg"""

    pass


C_FloatImg._fields_ = [
    ("magic", ct.c_ulong),
    ("width", ct.c_int),
    ("height", ct.c_int),
    ("type", ct.c_int),
    ("fval", ct.c_float),
    ("count", ct.c_int),
    ("R", ct.POINTER(ct.c_float)),
    ("G", ct.POINTER(ct.c_float)),
    ("B", ct.POINTER(ct.c_float)),
    ("A", ct.POINTER(ct.c_float)),
    ("reserved", ct.c_int),
]

############################################################################################################
# declaration of input / output types
c_fimgcreate = LIB.fimg_create
c_fimgcreate.argtypes = (ct.POINTER(C_FloatImg), ct.c_int, ct.c_int, ct.c_int)
c_fimgcreate.restype = ct.c_int

c_fimg_destroy = LIB.fimg_destroy
c_fimg_destroy.argtypes = (ct.POINTER(C_FloatImg),)
c_fimg_destroy.restype = ct.c_int

c_fimg_clone = LIB.fimg_clone
c_fimg_clone.argtypes = (ct.POINTER(C_FloatImg), ct.POINTER(C_FloatImg))
c_fimg_clone.restype = ct.c_int

c_fimg_copy_data = LIB.fimg_copy_data
c_fimg_copy_data.argtypes = (ct.POINTER(C_FloatImg), ct.POINTER(C_FloatImg))
c_fimg_copy_data.restype = ct.c_int

c_fimg_type_is_valid = LIB.fimg_type_is_valid
c_fimg_type_is_valid.argtypes = (ct.c_int,)
c_fimg_copy_data.restype = ct.c_int

c_fimg_str_type = LIB.fimg_str_type
c_fimg_str_type.argtypes = (ct.c_int,)
c_fimg_str_type.restype = ct.c_char_p

c_fimg_clear = LIB.fimg_clear
c_fimg_clear.argtypes = (ct.POINTER(C_FloatImg),)
c_fimg_clear.restype = ct.c_int


c_fimg_plot_rgb = LIB.fimg_plot_rgb
c_fimg_plot_rgb.argtypes = (
    ct.POINTER(C_FloatImg),
    ct.c_int,
    ct.c_int,
    ct.c_float,
    ct.c_float,
    ct.c_float,
)
c_fimg_plot_rgb.restype = ct.c_int


# int   fimg_get_rgb(FloatImg *head, int x, int y, float *rgb);
c_fimg_get_rgb = LIB.fimg_get_rgb
c_fimg_get_rgb.argtypes = (
    ct.POINTER(C_FloatImg),
    ct.c_int,
    ct.c_int,
    ct.POINTER(ct.c_float * 3),
)
c_fimg_get_rgb.restype = ct.c_int

# int   fimg_put_rgb(FloatImg *head, int x, int y, float *rgb);
c_fimg_put_rgb = LIB.fimg_put_rgb
c_fimg_put_rgb.argtypes = (
    ct.POINTER(C_FloatImg),
    ct.c_int,
    ct.c_int,
    ct.POINTER(ct.c_float * 3),
)
c_fimg_put_rgb.restype = ct.c_int

c_fimg_rgb_constant = LIB.fimg_rgb_constant
c_fimg_rgb_constant.argtypes = (
    ct.POINTER(C_FloatImg),
    ct.c_float,
    ct.c_float,
    ct.c_float,
)
c_fimg_rgb_constant.restype = ct.c_int

c_fimg_dump_to_file = LIB.fimg_dump_to_file
c_fimg_dump_to_file.argtypes = (ct.POINTER(C_FloatImg), ct.c_char_p, ct.c_int)
c_fimg_dump_to_file.restype = ct.c_int

c_fimg_load_from_dump = LIB.fimg_load_from_dump
c_fimg_load_from_dump.argtypes = (ct.c_char_p, ct.POINTER(C_FloatImg))
c_fimg_load_from_dump.restype = ct.c_int

c_fimg_fileinfos = LIB.fimg_fileinfos
c_fimg_fileinfos.argtypes = (ct.c_char_p, ct.POINTER(ct.c_int * 3))
c_fimg_fileinfos.restype = ct.c_int

############################################################################################################
class FloatImg:
    """

    Pythonic Object-Oriented encapsulation of floatimg library

    :attr c_img: an instance of C_FloatImg structure
    :attr c_img: an pointer to the c_img structure
    """

    # proxy attributes to the C_FloatImg structure
    # TODO: now more about them
    magic = property(lambda self: self.c_img.magic)
    fval = property(lambda self: self.c_img.fval)
    count = property(lambda self: self.c_img.count)

    # oh yeah, really really sluggish access to pixels img.R[0].contents
    # however, pixel data are not designed to be accessed this way
    # R = property(
    #     lambda self: pointer(self.c_img.contents.R)[: self.width * self.height]
    # )

    #######################################################################################################
    def __init__(self, c_img):
        self.c_img = c_img
        self.width = c_img.width
        self.height = c_img.height
        self.type_id = c_img.type
        # convenient pointer for later calls to C library
        self.c_img_p = ct.pointer(c_img)

    #######################################################################################################
    def __str__(self):
        return f"<{self.__class__.__name__} instance {id(self)} width={self.width} height={self.height} type={self.str_type}>"

    #######################################################################################################
    def destroy(self):
        """destroy the underlying structure. automattically called at instance destruction"""
        assert c_fimg_destroy(self.c_img) == 0

    #######################################################################################################
    def __del__(self):
        self.destroy()

    #######################################################################################################
    def clear(self):
        """clear data"""
        assert c_fimg_clear(self.c_img_p) == 0

    #######################################################################################################
    def clone(self, copy_data=False):
        """return a clone of the current instance"""
        if copy_data:
            flags = 1
        else:
            flags = 0
        new_pic = C_FloatImg()
        assert c_fimg_clone(self.c_img_p, ct.pointer(new_pic), flags) == 0
        return FloatImg(new_pic)

    #######################################################################################################
    def copy_data(self, to_img):
        assert c_fimg_copy_data(self.c_img_p, to_img.c_img_p) == 0

    #######################################################################################################
    @property
    def str_type(self):
        """return the type of the image as a string"""
        return c_fimg_str_type(self.c_img.type).decode("utf-8")

    #######################################################################################################
    def fill(self, color):
        assert c_fimg_rgb_constant(self.c_img_p, *color) == 0

    #######################################################################################################
    def get(self, x, y):
        """get r,g,b triplet from a pixel"""
        rgb = (ct.c_float * 3)()
        assert c_fimg_get_rgb(self.c_img_p, x, y, ct.pointer(rgb)) == 0
        return rgb[:3]

    #######################################################################################################
    def put(self, x, y, rgb):
        """put r,g,b triplet to a pixel"""
        # TODO may be a better way to create the array rather than iterating
        c_rgb = (ct.c_float * 3)()
        for i, c in enumerate(rgb):
            c_rgb[i] = c
        assert c_fimg_put_rgb(self.c_img_p, x, y, ct.pointer(c_rgb)) == 0

    #######################################################################################################
    def dump(self, fname):
        """save data to a dump file"""
        # TODO use system encoding instead of utf-8
        assert (
            c_fimg_dump_to_file(
                self.c_img_p, ct.c_char_p(bytes(fname, encoding="utf8")), 0
            )
            == 0
        )

    #######################################################################################################
    def load(self, fname):
        """load data from a dump. size and type have to be compatible"""
        assert (
            c_fimg_load_from_dump(
                ct.c_char_p(bytes(fname, encoding="utf8")), self.c_img_p
            )
            == 0
        )

    # TODO
    # fimg_plot_rgb
    # fimg_add_rgb

    # export(fname, flags) : depending file extension, save to the correct format


###########################################################################################################
def fileinfos(fname):
    """return witdh, height, img_type triplet read from a dump file"""
    datas = (ct.c_int * 3)()
    assert (
        c_fimg_fileinfos(ct.c_char_p(bytes(fname, encoding="utf8")), ct.pointer(datas))
        == 0
    )
    return datas[:3]


###########################################################################################################
def create(witdh, height, type_id):
    """create an new FloatImg instance"""
    assert type_is_valid(type_id)
    img = C_FloatImg()
    assert c_fimgcreate(ct.pointer(img), witdh, height, type_id) == 0
    return FloatImg(img)


###########################################################################################################
def create_rgb(witdh, height):
    """create a new rgb instance """
    return create(witdh, height, RGB)


###########################################################################################################
def create_from_dump(fname):
    """Create a new instance from a dump file"""
    witdh, height, img_type = fileinfos(fname)
    img = create(witdh, height, img_type)
    img.load(fname)
    return img


###########################################################################################################
def type_is_valid(type_id):
    """return True if type_id is a valid one"""
    return c_fimg_type_is_valid(type_id) == 1