# SPDX-License-Identifier: Apache-2.0

# ./blender.bin --background -noaudio --python tests/python/bl_pyapi_bpy_utils_units.py -- --verbose
import unittest

from bpy.utils import units


class UnitsTesting(unittest.TestCase):
    # From user typing to 'internal' Blender value.
    INPUT_TESTS = (
        # system,    type,    ref, input, value
        # LENGTH
        ('IMPERIAL', 'LENGTH', "", "1ft", 0.3048),
        ('IMPERIAL', 'LENGTH', "", "(1+1)ft", 0.3048 * 2),
        ('IMPERIAL', 'LENGTH', "", "1mi4\"", 1609.344 + 0.0254 * 4),
        ('METRIC', 'LENGTH', "", "0.005µm", 0.000001 * 0.005),
        ('METRIC', 'LENGTH', "", "1e6km", 1000.0 * 1e6),
        ('IMPERIAL', 'LENGTH', "", "1ft5cm", 0.3048 + 0.01 * 5),
        ('METRIC', 'LENGTH', "", "1ft5cm", 0.3048 + 0.01 * 5),
        # Using reference string to find a unit when none is given.
        ('IMPERIAL', 'LENGTH', "33.3ft", "1", 0.3048),
        ('METRIC', 'LENGTH', "33.3dm", "1", 0.1),
        ('IMPERIAL', 'LENGTH', "33.3cm", "1", 0.3048),  # ref unit is not in IMPERIAL system, default to feet...
        ('IMPERIAL', 'LENGTH', "33.3ft", "1\"", 0.0254),  # unused ref unit, since one is given already!
        ('IMPERIAL', 'LENGTH', "", "1+1ft", 0.3048 * 2),  # default unit taken from current string (feet).
        ('METRIC', 'LENGTH', "", "1+1ft", 1.3048),  # no metric units, we default to meters.
        ('IMPERIAL', 'LENGTH', "", "3+1in+1ft", 0.3048 * 4 + 0.0254),  # bigger unit becomes default one!
        ('IMPERIAL', 'LENGTH', "", "(3+1)in+1ft", 0.3048 + 0.0254 * 4),
    )

    # From 'internal' Blender value to user-friendly printing
    OUTPUT_TESTS = (
        # system,    type,    prec, sep, compat, value, output
        # LENGTH
        # Note: precision handling is a bit complicated when using multi-units...
        ('IMPERIAL', 'LENGTH', 3, False, False, 0.3048, "1'"),
        ('IMPERIAL', 'LENGTH', 3, False, True, 0.3048, "1ft"),
        ('IMPERIAL', 'LENGTH', 4, True, False, 0.3048 * 2 + 0.0254 * 5.5, "2' 5.5\""),
        ('IMPERIAL', 'LENGTH', 3, False, False, 1609.344 * 1e6, "1000000 mi"),
        ('IMPERIAL', 'LENGTH', 6, False, False, 1609.344 * 1e6, "1000000 mi"),
        ('METRIC', 'LENGTH', 3, True, False, 1000 * 2 + 0.001 * 15, "2 km 2 cm"),
        ('METRIC', 'LENGTH', 5, True, False, 1234.56789, "1 km 234.6 m"),
        ('METRIC', 'LENGTH', 6, True, False, 1234.56789, "1 km 234.57 m"),
        ('METRIC', 'LENGTH', 9, False, False, 1234.56789, "1.234568 km"),
        ('METRIC', 'LENGTH', 9, True, False, 1000.000123456789, "1 km 0.123 mm"),
    )

    def test_units_inputs(self):
        # Stolen from FBX addon!
        def similar_values(v1, v2, e):
            if v1 == v2:
                return True
            return ((abs(v1 - v2) / max(abs(v1), abs(v2))) <= e)

        for usys, utype, ref, inpt, val in self.INPUT_TESTS:
            opt_val = units.to_value(usys, utype, inpt, str_ref_unit=ref)
            # Note: almostequal is not good here, precision is fixed on decimal digits, not variable with
            # magnitude of numbers (i.e. 1609.4416 ~= 1609.4456 fails even at 5 of 'places'...).
            self.assertTrue(similar_values(opt_val, val, 1e-7),
                            msg="%s, %s: \"%s\" (ref: \"%s\") => %f, expected %f"
                                "" % (usys, utype, inpt, ref, opt_val, val))

    def test_units_outputs(self):
        for usys, utype, prec, sep, compat, val, output in self.OUTPUT_TESTS:
            opt_str = units.to_string(usys, utype, val, precision=prec, split_unit=sep, compatible_unit=compat)
            self.assertEqual(
                opt_str, output,
                msg=(
                    "%s, %s: %f (precision: %d, separate units: %d, compat units: %d) => "
                    "\"%s\", expected \"%s\""
                ) % (usys, utype, val, prec, sep, compat, opt_str, output)
            )


if __name__ == '__main__':
    import sys
    sys.argv = [__file__] + (sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else [])
    unittest.main()