#!/usr/bin/env python3
# ******************************************************************************
#  $Id$
#
#  Project:  GDAL
#  Purpose:  Convert GCPs to a point layer.
#  Author:   Frank Warmerdam, warmerdam@pobox.com
#
# ******************************************************************************
#  Copyright (c) 2005, Frank Warmerdam <warmerdam@pobox.com>
#  Copyright (c) 2021, Idan Miara <idan@miara.com>
#
# SPDX-License-Identifier: MIT
# ******************************************************************************

import sys

from osgeo import gdal, ogr, osr


def Usage():
    print("Usage: gcps2vec.py [-of <ogr_drivername>] [-p] <raster_file> <vector_file>")
    return 2


def main(argv=sys.argv):
    src_filename = None
    dst_filename = None
    driver_name = "GML"
    pixel_out = False

    argv = gdal.GeneralCmdLineProcessor(argv)
    if argv is None:
        return 0

    # Parse command line arguments.
    i = 1
    while i < len(argv):
        arg = argv[i]

        if arg == "-of":
            i = i + 1
            driver_name = argv[i]

        elif arg == "-p":
            pixel_out = True

        elif src_filename is None:
            src_filename = argv[i]

        elif dst_filename is None:
            dst_filename = argv[i]

        else:
            return Usage()

        i = i + 1

    if dst_filename is None:
        return Usage()

    return gcps2vec(
        src_filename=src_filename,
        dst_filename=dst_filename,
        driver_name=driver_name,
        pixel_out=pixel_out,
    )


def gcps2vec(
    src_filename: str, dst_filename: str, driver_name: str, pixel_out: bool = False
):
    # ----------------------------------------------------------------------------
    # Open input file, and fetch GCPs.
    # ----------------------------------------------------------------------------
    ds = gdal.Open(src_filename)
    if ds is None:
        print(f"Unable to open {src_filename}")
        return 1

    gcp_srs = ds.GetGCPProjection()
    gcps = ds.GetGCPs()

    ds = None

    if gcps is None or not gcps:
        print(f"No GCPs on file {src_filename}!")
        return 1

    # ----------------------------------------------------------------------------
    # Create output file, and layer.
    # ----------------------------------------------------------------------------

    driver = ogr.GetDriverByName(driver_name)
    if driver is None:
        print(f"No driver named {driver_name} available.")
        return 1

    ds = driver.CreateDataSource(dst_filename)

    if not pixel_out and gcp_srs != "":
        srs = osr.SpatialReference()
        srs.ImportFromWkt(gcp_srs)
    else:
        srs = None

    if not pixel_out:
        geom_type = ogr.wkbPoint25D
    else:
        geom_type = ogr.wkbPoint

    layer = ds.CreateLayer("gcps", srs, geom_type=geom_type)

    if not pixel_out:
        fd = ogr.FieldDefn("Pixel", ogr.OFTReal)
        layer.CreateField(fd)

        fd = ogr.FieldDefn("Line", ogr.OFTReal)
        layer.CreateField(fd)
    else:
        fd = ogr.FieldDefn("X", ogr.OFTReal)
        layer.CreateField(fd)

        fd = ogr.FieldDefn("Y", ogr.OFTReal)
        layer.CreateField(fd)

        fd = ogr.FieldDefn("Z", ogr.OFTReal)
        layer.CreateField(fd)

    fd = ogr.FieldDefn("Id", ogr.OFTString)
    layer.CreateField(fd)

    fd = ogr.FieldDefn("Info", ogr.OFTString)
    layer.CreateField(fd)

    # ----------------------------------------------------------------------------
    # Write GCPs.
    # ----------------------------------------------------------------------------

    for gcp in gcps:

        feat = ogr.Feature(layer.GetLayerDefn())

        if not pixel_out:
            geom = ogr.Geometry(geom_type)
            feat.SetField("Pixel", gcp.GCPPixel)
            feat.SetField("Line", gcp.GCPLine)
            geom.SetPoint(0, gcp.GCPX, gcp.GCPY, gcp.GCPZ)
        else:
            geom = ogr.Geometry(geom_type)
            feat.SetField("X", gcp.GCPX)
            feat.SetField("Y", gcp.GCPY)
            feat.SetField("Z", gcp.GCPZ)
            geom.SetPoint(0, gcp.GCPPixel, gcp.GCPLine)

        feat.SetField("Id", gcp.Id)
        feat.SetField("Info", gcp.Info)

        feat.SetGeometryDirectly(geom)
        layer.CreateFeature(feat)

    feat = None
    ds.Destroy()


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