# Copyright (c) Facebook, Inc. and its affiliates. All rights reserved.

import struct
import unittest
from io import BytesIO, StringIO

import torch
from common_testing import TestCaseMixin
from pytorch3d.io.ply_io import _load_ply_raw, load_ply, save_ply
from pytorch3d.utils import torus


class TestMeshPlyIO(TestCaseMixin, unittest.TestCase):
    def test_raw_load_simple_ascii(self):
        ply_file = "\n".join(
            [
                "ply",
                "format ascii 1.0",
                "comment made by Greg Turk",
                "comment this file is a cube",
                "element vertex 8",
                "property float x",
                "property float y",
                "property float z",
                "element face 6",
                "property list uchar int vertex_index",
                "element irregular_list 3",
                "property list uchar int vertex_index",
                "end_header",
                "0 0 0",
                "0 0 1",
                "0 1 1",
                "0 1 0",
                "1 0 0",
                "1 0 1",
                "1 1 1",
                "1 1 0",
                "4 0 1 2 3",
                "4 7 6 5 4",
                "4 0 4 5 1",
                "4 1 5 6 2",
                "4 2 6 7 3",
                "4 3 7 4 0",  # end of faces
                "4 0 1 2 3",
                "4 7 6 5 4",
                "3 4 5 1",
            ]
        )
        for line_ending in [None, "\n", "\r\n"]:
            if line_ending is None:
                stream = StringIO(ply_file)
            else:
                byte_file = ply_file.encode("ascii")
                if line_ending == "\r\n":
                    byte_file = byte_file.replace(b"\n", b"\r\n")
                stream = BytesIO(byte_file)
            header, data = _load_ply_raw(stream)
            self.assertTrue(header.ascii)
            self.assertEqual(len(data), 3)
            self.assertTupleEqual(data["face"].shape, (6, 4))
            self.assertClose([0, 1, 2, 3], data["face"][0])
            self.assertClose([3, 7, 4, 0], data["face"][5])
            self.assertTupleEqual(data["vertex"].shape, (8, 3))
            irregular = data["irregular_list"]
            self.assertEqual(len(irregular), 3)
            self.assertEqual(type(irregular), list)
            [x] = irregular[0]
            self.assertClose(x, [0, 1, 2, 3])
            [x] = irregular[1]
            self.assertClose(x, [7, 6, 5, 4])
            [x] = irregular[2]
            self.assertClose(x, [4, 5, 1])

    def test_load_simple_ascii(self):
        ply_file = "\n".join(
            [
                "ply",
                "format ascii 1.0",
                "comment made by Greg Turk",
                "comment this file is a cube",
                "element vertex 8",
                "property float x",
                "property float y",
                "property float z",
                "element face 6",
                "property list uchar int vertex_index",
                "end_header",
                "0 0 0",
                "0 0 1",
                "0 1 1",
                "0 1 0",
                "1 0 0",
                "1 0 1",
                "1 1 1",
                "1 1 0",
                "4 0 1 2 3",
                "4 7 6 5 4",
                "4 0 4 5 1",
                "4 1 5 6 2",
                "4 2 6 7 3",
                "4 3 7 4 0",
            ]
        )
        for line_ending in [None, "\n", "\r\n"]:
            if line_ending is None:
                stream = StringIO(ply_file)
            else:
                byte_file = ply_file.encode("ascii")
                if line_ending == "\r\n":
                    byte_file = byte_file.replace(b"\n", b"\r\n")
                stream = BytesIO(byte_file)
            verts, faces = load_ply(stream)
            self.assertEqual(verts.shape, (8, 3))
            self.assertEqual(faces.shape, (12, 3))
            verts_expected = [
                [0, 0, 0],
                [0, 0, 1],
                [0, 1, 1],
                [0, 1, 0],
                [1, 0, 0],
                [1, 0, 1],
                [1, 1, 1],
                [1, 1, 0],
            ]
            self.assertClose(verts, torch.FloatTensor(verts_expected))
            faces_expected = [
                [0, 1, 2],
                [7, 6, 5],
                [0, 4, 5],
                [1, 5, 6],
                [2, 6, 7],
                [3, 7, 4],
                [0, 2, 3],
                [7, 5, 4],
                [0, 5, 1],
                [1, 6, 2],
                [2, 7, 3],
                [3, 4, 0],
            ]
            self.assertClose(faces, torch.LongTensor(faces_expected))

    def test_save_ply_invalid_shapes(self):
        # Invalid vertices shape
        with self.assertRaises(ValueError) as error:
            verts = torch.FloatTensor([[0.1, 0.2, 0.3, 0.4]])  # (V, 4)
            faces = torch.LongTensor([[0, 1, 2]])
            save_ply(StringIO(), verts, faces)
        expected_message = (
            "Argument 'verts' should either be empty or of shape (num_verts, 3)."
        )
        self.assertTrue(expected_message, error.exception)

        # Invalid faces shape
        with self.assertRaises(ValueError) as error:
            verts = torch.FloatTensor([[0.1, 0.2, 0.3]])
            faces = torch.LongTensor([[0, 1, 2, 3]])  # (F, 4)
            save_ply(StringIO(), verts, faces)
        expected_message = (
            "Argument 'faces' should either be empty or of shape (num_faces, 3)."
        )
        self.assertTrue(expected_message, error.exception)

    def test_save_ply_invalid_indices(self):
        message_regex = "Faces have invalid indices"
        verts = torch.FloatTensor([[0.1, 0.2, 0.3]])
        faces = torch.LongTensor([[0, 1, 2]])
        with self.assertWarnsRegex(UserWarning, message_regex):
            save_ply(StringIO(), verts, faces)

        faces = torch.LongTensor([[-1, 0, 1]])
        with self.assertWarnsRegex(UserWarning, message_regex):
            save_ply(StringIO(), verts, faces)

    def _test_save_load(self, verts, faces):
        f = StringIO()
        save_ply(f, verts, faces)
        f.seek(0)
        # raise Exception(f.getvalue())
        expected_verts, expected_faces = verts, faces
        if not len(expected_verts):  # Always compare with a (V, 3) tensor
            expected_verts = torch.zeros(size=(0, 3), dtype=torch.float32)
        if not len(expected_faces):  # Always compare with an (F, 3) tensor
            expected_faces = torch.zeros(size=(0, 3), dtype=torch.int64)
        actual_verts, actual_faces = load_ply(f)
        self.assertClose(expected_verts, actual_verts)
        self.assertClose(expected_faces, actual_faces)

    def test_empty_save_load(self):
        # Vertices + empty faces
        verts = torch.tensor([[0.1, 0.2, 0.3]])
        faces = torch.LongTensor([])
        self._test_save_load(verts, faces)

        faces = torch.zeros(size=(0, 3), dtype=torch.int64)
        self._test_save_load(verts, faces)

        # Faces + empty vertices
        message_regex = "Faces have invalid indices"
        verts = torch.FloatTensor([])
        faces = torch.LongTensor([[0, 1, 2]])
        with self.assertWarnsRegex(UserWarning, message_regex):
            self._test_save_load(verts, faces)

        verts = torch.zeros(size=(0, 3), dtype=torch.float32)
        with self.assertWarnsRegex(UserWarning, message_regex):
            self._test_save_load(verts, faces)

        # Empty vertices + empty faces
        message_regex = "Empty 'verts' and 'faces' arguments provided"
        verts0 = torch.FloatTensor([])
        faces0 = torch.LongTensor([])
        with self.assertWarnsRegex(UserWarning, message_regex):
            self._test_save_load(verts0, faces0)

        faces3 = torch.zeros(size=(0, 3), dtype=torch.int64)
        with self.assertWarnsRegex(UserWarning, message_regex):
            self._test_save_load(verts0, faces3)

        verts3 = torch.zeros(size=(0, 3), dtype=torch.float32)
        with self.assertWarnsRegex(UserWarning, message_regex):
            self._test_save_load(verts3, faces0)

        with self.assertWarnsRegex(UserWarning, message_regex):
            self._test_save_load(verts3, faces3)

    def test_simple_save(self):
        verts = torch.tensor(
            [[0, 0, 0], [0, 0, 1], [0, 1, 0], [1, 0, 0]], dtype=torch.float32
        )
        faces = torch.tensor([[0, 1, 2], [0, 3, 4]])
        file = StringIO()
        save_ply(file, verts=verts, faces=faces)
        file.seek(0)
        verts2, faces2 = load_ply(file)
        self.assertClose(verts, verts2)
        self.assertClose(faces, faces2)

    def test_load_simple_binary(self):
        for big_endian in [True, False]:
            verts = (
                "0 0 0 " "0 0 1 " "0 1 1 " "0 1 0 " "1 0 0 " "1 0 1 " "1 1 1 " "1 1 0"
            ).split()
            faces = (
                "4 0 1 2 3 "
                "4 7 6 5 4 "
                "4 0 4 5 1 "
                "4 1 5 6 2 "
                "4 2 6 7 3 "
                "4 3 7 4 0 "  # end of first 6
                "4 0 1 2 3 "
                "4 7 6 5 4 "
                "3 4 5 1"
            ).split()
            short_one = b"\00\01" if big_endian else b"\01\00"
            mixed_data = b"\00\00" b"\03\03" + (short_one + b"\00\01\01\01" b"\00\02")
            minus_one_data = b"\xff" * 14
            endian_char = ">" if big_endian else "<"
            format = (
                "format binary_big_endian 1.0"
                if big_endian
                else "format binary_little_endian 1.0"
            )
            vertex_pattern = endian_char + "24f"
            vertex_data = struct.pack(vertex_pattern, *map(float, verts))
            vertex1_pattern = endian_char + "fdffdffdffdffdffdffdffdf"
            vertex1_data = struct.pack(vertex1_pattern, *map(float, verts))
            face_char_pattern = endian_char + "44b"
            face_char_data = struct.pack(face_char_pattern, *map(int, faces))
            header = "\n".join(
                [
                    "ply",
                    format,
                    "element vertex 8",
                    "property float x",
                    "property float y",
                    "property float z",
                    "element vertex1 8",
                    "property float x",
                    "property double y",
                    "property float z",
                    "element face 6",
                    "property list uchar uchar vertex_index",
                    "element irregular_list 3",
                    "property list uchar uchar vertex_index",
                    "element mixed 2",
                    "property list short uint foo",
                    "property short bar",
                    "element minus_ones 1",
                    "property char 1",
                    "property uchar 2",
                    "property short 3",
                    "property ushort 4",
                    "property int 5",
                    "property uint 6",
                    "end_header\n",
                ]
            )
            ply_file = b"".join(
                [
                    header.encode("ascii"),
                    vertex_data,
                    vertex1_data,
                    face_char_data,
                    mixed_data,
                    minus_one_data,
                ]
            )
            metadata, data = _load_ply_raw(BytesIO(ply_file))
            self.assertFalse(metadata.ascii)
            self.assertEqual(len(data), 6)
            self.assertTupleEqual(data["face"].shape, (6, 4))
            self.assertClose([0, 1, 2, 3], data["face"][0])
            self.assertClose([3, 7, 4, 0], data["face"][5])

            self.assertTupleEqual(data["vertex"].shape, (8, 3))
            self.assertEqual(len(data["vertex1"]), 8)
            self.assertClose(data["vertex"], data["vertex1"])
            self.assertClose(data["vertex"].flatten(), list(map(float, verts)))

            irregular = data["irregular_list"]
            self.assertEqual(len(irregular), 3)
            self.assertEqual(type(irregular), list)
            [x] = irregular[0]
            self.assertClose(x, [0, 1, 2, 3])
            [x] = irregular[1]
            self.assertClose(x, [7, 6, 5, 4])
            [x] = irregular[2]
            self.assertClose(x, [4, 5, 1])

            mixed = data["mixed"]
            self.assertEqual(len(mixed), 2)
            self.assertEqual(len(mixed[0]), 2)
            self.assertEqual(len(mixed[1]), 2)
            self.assertEqual(mixed[0][1], 3 * 256 + 3)
            self.assertEqual(len(mixed[0][0]), 0)
            self.assertEqual(mixed[1][1], (2 if big_endian else 2 * 256))
            base = 1 + 256 + 256 * 256
            self.assertEqual(len(mixed[1][0]), 1)
            self.assertEqual(mixed[1][0][0], base if big_endian else 256 * base)

            self.assertListEqual(
                data["minus_ones"], [(-1, 255, -1, 65535, -1, 4294967295)]
            )

    def test_bad_ply_syntax(self):
        """Some syntactically bad ply files."""
        lines = [
            "ply",
            "format ascii 1.0",
            "comment dashfadskfj;k",
            "element vertex 1",
            "property float x",
            "element listy 1",
            "property list uint int x",
            "end_header",
            "0",
            "0",
        ]
        lines2 = lines.copy()
        # this is ok
        _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines.copy()
        lines2[0] = "PLY"
        with self.assertRaisesRegex(ValueError, "Invalid file header."):
            _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines.copy()
        lines2[2] = "#this is a comment"
        with self.assertRaisesRegex(ValueError, "Invalid line.*"):
            _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines.copy()
        lines2[3] = lines[4]
        lines2[4] = lines[3]
        with self.assertRaisesRegex(
            ValueError, "Encountered property before any element."
        ):
            _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines.copy()
        lines2[8] = "1 2"
        with self.assertRaisesRegex(ValueError, "Inconsistent data for vertex."):
            _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines[:-1]
        with self.assertRaisesRegex(ValueError, "Not enough data for listy."):
            _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines.copy()
        lines2[5] = "element listy 2"
        with self.assertRaisesRegex(ValueError, "Not enough data for listy."):
            _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines.copy()
        lines2.insert(4, "property short x")
        with self.assertRaisesRegex(
            ValueError, "Cannot have two properties called x in vertex."
        ):
            _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines.copy()
        lines2.insert(4, "property zz short")
        with self.assertRaisesRegex(ValueError, "Invalid datatype: zz"):
            _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines.copy()
        lines2.append("3")
        with self.assertRaisesRegex(ValueError, "Extra data at end of file."):
            _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines.copy()
        lines2.append("comment foo")
        with self.assertRaisesRegex(ValueError, "Extra data at end of file."):
            _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines.copy()
        lines2.insert(4, "element bad 1")
        with self.assertRaisesRegex(ValueError, "Found an element with no properties."):
            _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines.copy()
        lines2[-1] = "3 2 3 3"
        _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines.copy()
        lines2[-1] = "3 1 2 3 4"
        msg = "A line of listy data did not have the specified length."
        with self.assertRaisesRegex(ValueError, msg):
            _load_ply_raw(StringIO("\n".join(lines2)))

        lines2 = lines.copy()
        lines2[3] = "element vertex one"
        msg = "Number of items for vertex was not a number."
        with self.assertRaisesRegex(ValueError, msg):
            _load_ply_raw(StringIO("\n".join(lines2)))

        # Heterogenous cases
        lines2 = lines.copy()
        lines2.insert(4, "property double y")

        with self.assertRaisesRegex(ValueError, "Too little data for an element."):
            _load_ply_raw(StringIO("\n".join(lines2)))

        lines2[-2] = "3.3 4.2"
        _load_ply_raw(StringIO("\n".join(lines2)))

        lines2[-2] = "3.3 4.3 2"
        with self.assertRaisesRegex(ValueError, "Too much data for an element."):
            _load_ply_raw(StringIO("\n".join(lines2)))

        # Now make the ply file actually be readable as a Mesh

        with self.assertRaisesRegex(ValueError, "The ply file has no face element."):
            load_ply(StringIO("\n".join(lines)))

        lines2 = lines.copy()
        lines2[5] = "element face 1"
        with self.assertRaisesRegex(ValueError, "Invalid vertices in file."):
            load_ply(StringIO("\n".join(lines2)))

        lines2.insert(5, "property float z")
        lines2.insert(5, "property float y")
        lines2[-2] = "0 0 0"
        lines2[-1] = ""
        with self.assertRaisesRegex(ValueError, "Not enough data for face."):
            load_ply(StringIO("\n".join(lines2)))

        lines2[-1] = "2 0 0"
        with self.assertRaisesRegex(ValueError, "Faces must have at least 3 vertices."):
            load_ply(StringIO("\n".join(lines2)))

        # Good one
        lines2[-1] = "3 0 0 0"
        load_ply(StringIO("\n".join(lines2)))

    @staticmethod
    def _bm_save_ply(verts: torch.Tensor, faces: torch.Tensor, decimal_places: int):
        return lambda: save_ply(StringIO(), verts, faces, decimal_places=decimal_places)

    @staticmethod
    def _bm_load_ply(verts: torch.Tensor, faces: torch.Tensor, decimal_places: int):
        f = StringIO()
        save_ply(f, verts, faces, decimal_places)
        s = f.getvalue()
        # Recreate stream so it's unaffected by how it was created.
        return lambda: load_ply(StringIO(s))

    @staticmethod
    def bm_save_simple_ply_with_init(V: int, F: int):
        verts = torch.tensor(V * [[0.11, 0.22, 0.33]]).view(-1, 3)
        faces = torch.tensor(F * [[0, 1, 2]]).view(-1, 3)
        return TestMeshPlyIO._bm_save_ply(verts, faces, decimal_places=2)

    @staticmethod
    def bm_load_simple_ply_with_init(V: int, F: int):
        verts = torch.tensor([[0.1, 0.2, 0.3]]).expand(V, 3)
        faces = torch.tensor([[0, 1, 2]], dtype=torch.int64).expand(F, 3)
        return TestMeshPlyIO._bm_load_ply(verts, faces, decimal_places=2)

    @staticmethod
    def bm_save_complex_ply(N: int):
        meshes = torus(r=0.25, R=1.0, sides=N, rings=2 * N)
        [verts], [faces] = meshes.verts_list(), meshes.faces_list()
        return TestMeshPlyIO._bm_save_ply(verts, faces, decimal_places=5)

    @staticmethod
    def bm_load_complex_ply(N: int):
        meshes = torus(r=0.25, R=1.0, sides=N, rings=2 * N)
        [verts], [faces] = meshes.verts_list(), meshes.faces_list()
        return TestMeshPlyIO._bm_load_ply(verts, faces, decimal_places=5)
