#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# ******************************************************************************
#
#  Project:  GDAL
#  Purpose:  Compare two files for differences and report.
#  Author:   Frank Warmerdam, warmerdam@pobox.com
#
# ******************************************************************************
#  Copyright (c) 2012, Frank Warmerdam <warmerdam@pobox.com>
#  Copyright (c) 2021, Idan Miara <idan@miara.com>
#
#  Permission is hereby granted, free of charge, to any person obtaining a
#  copy of this software and associated documentation files (the "Software"),
#  to deal in the Software without restriction, including without limitation
#  the rights to use, copy, modify, merge, publish, distribute, sublicense,
#  and/or sell copies of the Software, and to permit persons to whom the
#  Software is furnished to do so, subject to the following conditions:
#
#  The above copyright notice and this permission notice shall be included
#  in all copies or substantial portions of the Software.
#
#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
#  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
#  THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
#  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
#  DEALINGS IN THE SOFTWARE.
# ******************************************************************************

import filecmp
import os
import sys

from osgeo import gdal, osr

#######################################################
from osgeo_utils.auxiliary.base import PathLikeOrStr


def compare_metadata(golden_md, new_md, ident, options=None):
    # pylint: disable=unused-argument

    if golden_md is None and new_md is None:
        return 0

    found_diff = 0

    if len(list(golden_md.keys())) != len(list(new_md.keys())):
        print("Difference in %s metadata key count" % ident)
        print("  Golden Keys: " + str(list(golden_md.keys())))
        print("  New Keys: " + str(list(new_md.keys())))
        found_diff += 1

    for key in list(golden_md.keys()):
        if key not in new_md:
            print('New %s metadata lacks key "%s"' % (ident, key))
            found_diff += 1
        elif new_md[key] != golden_md[key]:
            print('Metadata value difference for key "' + key + '"')
            print('  Golden: "' + golden_md[key] + '"')
            print('  New:    "' + new_md[key] + '"')
            found_diff += 1

    return found_diff


#######################################################
# Review and report on the actual image pixels that differ.
def compare_image_pixels(golden_band, new_band, ident, options=None):
    # pylint: disable=unused-argument

    diff_count = 0
    max_diff = 0

    for line in range(golden_band.YSize):
        golden_line = golden_band.ReadAsArray(0, line, golden_band.XSize, 1)[0]
        new_line = new_band.ReadAsArray(0, line, golden_band.XSize, 1)[0]
        diff_line = golden_line.astype(float) - new_line.astype(float)
        max_diff = max(max_diff, abs(diff_line).max())
        diff_count += len(diff_line.nonzero()[0])

    print("  Pixels Differing: " + str(diff_count))
    print("  Maximum Pixel Difference: " + str(max_diff))


#######################################################


def compare_band(golden_band, new_band, ident, options=None):
    found_diff = 0

    options = [] if options is None else options

    if golden_band.DataType != new_band.DataType:
        print("Band %s pixel types differ." % ident)
        print("  Golden: " + gdal.GetDataTypeName(golden_band.DataType))
        print("  New:    " + gdal.GetDataTypeName(new_band.DataType))
        found_diff += 1

    if golden_band.GetNoDataValue() != new_band.GetNoDataValue():
        print("Band %s nodata values differ." % ident)
        print("  Golden: " + str(golden_band.GetNoDataValue()))
        print("  New:    " + str(new_band.GetNoDataValue()))
        found_diff += 1

    if golden_band.GetColorInterpretation() != new_band.GetColorInterpretation():
        print("Band %s color interpretation values differ." % ident)
        print(
            "  Golden: "
            + gdal.GetColorInterpretationName(golden_band.GetColorInterpretation())
        )
        print(
            "  New:    "
            + gdal.GetColorInterpretationName(new_band.GetColorInterpretation())
        )
        found_diff += 1

    if golden_band.Checksum() != new_band.Checksum():
        print("Band %s checksum difference:" % ident)
        print("  Golden: " + str(golden_band.Checksum()))
        print("  New:    " + str(new_band.Checksum()))
        found_diff += 1
        compare_image_pixels(golden_band, new_band, ident, options)

    # Check overviews
    if golden_band.GetOverviewCount() != new_band.GetOverviewCount():
        print("Band %s overview count difference:" % ident)
        print("  Golden: " + str(golden_band.GetOverviewCount()))
        print("  New:    " + str(new_band.GetOverviewCount()))
        found_diff += 1
    else:
        for i in range(golden_band.GetOverviewCount()):
            found_diff += compare_band(
                golden_band.GetOverview(i),
                new_band.GetOverview(i),
                ident + " overview " + str(i),
                options,
            )

    # Metadata
    if "SKIP_METADATA" not in options:
        found_diff += compare_metadata(
            golden_band.GetMetadata(), new_band.GetMetadata(), "Band " + ident, options
        )

    # Mask band
    if golden_band.GetMaskFlags() != new_band.GetMaskFlags():
        print("Band %s mask flags difference:" % ident)
        print("  Golden: " + str(golden_band.GetMaskFlags()))
        print("  New:    " + str(new_band.GetMaskFlags()))
        found_diff += 1
    elif golden_band.GetMaskFlags() in (gdal.GMF_PER_DATASET, 0):
        found_diff += compare_band(
            golden_band.GetMaskBand(),
            new_band.GetMaskBand(),
            ident + " mask band",
            options,
        )

    # TODO: Color Table, gain/bias, units, blocksize, min/max

    return found_diff


#######################################################


def compare_srs(golden_wkt, new_wkt):
    if golden_wkt == new_wkt:
        return 0

    print("Difference in SRS!")

    golden_srs = osr.SpatialReference(golden_wkt)
    new_srs = osr.SpatialReference(new_wkt)

    if golden_srs.IsSame(new_srs):
        print("  * IsSame() reports them as equivalent.")
    else:
        print("  * IsSame() reports them as different.")

    print("  Golden:")
    print("  " + golden_srs.ExportToPrettyWkt())
    print("  New:")
    print("  " + new_srs.ExportToPrettyWkt())

    return 1


#######################################################


def compare_db(golden_db, new_db, options=None):
    found_diff = 0

    options = [] if options is None else options

    # SRS
    if "SKIP_SRS" not in options:
        found_diff += compare_srs(golden_db.GetProjection(), new_db.GetProjection())

    # GeoTransform
    if "SKIP_GEOTRANSFORM" not in options:
        golden_gt = golden_db.GetGeoTransform()
        new_gt = new_db.GetGeoTransform()
        if golden_gt != new_gt:
            print("GeoTransforms Differ:")
            print("  Golden: " + str(golden_gt))
            print("  New:    " + str(new_gt))
            found_diff += 1

    # Metadata
    if "SKIP_METADATA" not in options:
        found_diff += compare_metadata(
            golden_db.GetMetadata(), new_db.GetMetadata(), "Dataset", options
        )

    # Bands
    if golden_db.RasterCount != new_db.RasterCount:
        print(
            "Band count mismatch (golden=%d, new=%d)"
            % (golden_db.RasterCount, new_db.RasterCount)
        )
        found_diff += 1

    # Dimensions
    for i in range(golden_db.RasterCount):
        gSzX = golden_db.GetRasterBand(i + 1).XSize
        nSzX = new_db.GetRasterBand(i + 1).XSize
        gSzY = golden_db.GetRasterBand(i + 1).YSize
        nSzY = new_db.GetRasterBand(i + 1).YSize

        if gSzX != nSzX or gSzY != nSzY:
            print(
                "Band size mismatch (band=%d golden=[%d,%d], new=[%d,%d])"
                % (i, gSzX, gSzY, nSzX, nSzY)
            )
            found_diff += 1

    # If so-far-so-good, then compare pixels
    if found_diff == 0:
        for i in range(golden_db.RasterCount):
            found_diff += compare_band(
                golden_db.GetRasterBand(i + 1),
                new_db.GetRasterBand(i + 1),
                str(i + 1),
                options,
            )

    return found_diff


#######################################################


def compare_sds(golden_db, new_db, options=None):
    found_diff = 0

    options = [] if options is None else options

    golden_sds = golden_db.GetMetadata("SUBDATASETS")
    new_sds = new_db.GetMetadata("SUBDATASETS")

    count = len(list(golden_sds.keys())) // 2
    for i in range(count):
        key = "SUBDATASET_%d_NAME" % (i + 1)

        sub_golden_db = gdal.Open(golden_sds[key])
        sub_new_db = gdal.Open(new_sds[key])

        sds_diff = compare_db(sub_golden_db, sub_new_db, options)
        found_diff += sds_diff
        if sds_diff > 0:
            print(
                "%d differences found between:\n  %s\n  %s"
                % (sds_diff, golden_sds[key], new_sds[key])
            )

    return found_diff


#######################################################


def find_diff(
    golden_file: PathLikeOrStr, new_file: PathLikeOrStr, check_sds: bool = False
):
    # Compare Files
    found_diff = 0

    # compare raw binary files.
    try:
        os.stat(golden_file)

        if not filecmp.cmp(golden_file, new_file):
            print("Files differ at the binary level.")
            found_diff += 1
    except OSError:
        print("Skipped binary file comparison, golden file not in filesystem.")

    # compare as GDAL Datasets.
    golden_db = gdal.Open(golden_file)
    new_db = gdal.Open(new_file)
    found_diff += compare_db(golden_db, new_db)

    if check_sds:
        found_diff += compare_sds(golden_db, new_db)

    return found_diff


#######################################################


def Usage():
    print("Usage: gdalcompare.py [-sds] <golden_file> <new_file>")
    return 2


#######################################################
#
# Mainline
#


def main(argv=sys.argv):
    # Default GDAL argument parsing.
    argv = gdal.GeneralCmdLineProcessor(argv)
    if argv is None:
        return 0

    if len(argv) == 1:
        return Usage()

    # Script argument parsing.
    golden_file = None
    new_file = None
    check_sds = 0

    i = 1
    while i < len(argv):

        if argv[i] == "-sds":
            check_sds = 1

        elif golden_file is None:
            golden_file = argv[i]

        elif new_file is None:
            new_file = argv[i]

        else:
            print("Unrecognised argument: " + argv[i])
            return Usage()

        i = i + 1
        # next argument

    found_diff = find_diff(golden_file, new_file, check_sds)
    print("Differences Found: " + str(found_diff))
    sys.exit(found_diff)


if __name__ == "__main__":
    sys.exit(main(sys.argv))