Geografic-Information-System/scripts/v.to.lines/v.to.lines.py

#!/usr/bin/env python3

############################################################################
#
# MODULE:       v.to.lines (former v.polytoline)
# AUTHOR(S):    Luca Delucchi
#               point support added by Markus Neteler
#
# PURPOSE:      Converts polygons and points to lines
# COPYRIGHT:    (C) 2013-2014 by the GRASS Development Team
#
#               This program is free software under the GNU General Public
#               License (version 2). Read the file COPYING that comes with GRASS
#               for details.
# TODO
#    support centroids (treat as points)?
#############################################################################

# %module
# % description: Converts vector polygons or points to lines.
# % keyword: vector
# % keyword: geometry
# % keyword: area
# % keyword: line
# % keyword: point
# %end

# %option G_OPT_V_INPUT
# %end

# %option G_OPT_V_OUTPUT
# %end

# %option
# % key: method
# % type: string
# % description: Method used for point interpolation
# % options: delaunay
# % answer: delaunay
# % guisection: Area
# %end

import grass.script as grass
from grass.script.utils import decode
from grass.exceptions import CalledModuleError
import os


def main():
    # Get the options
    input = options["input"]
    input_name = input.split("@")[0]
    output = options["output"]
    method = options["method"]
    min_cat = None
    max_cat = None
    point = None
    overwrite = grass.overwrite()

    quiet = True

    if grass.verbosity() > 2:
        quiet = False

    in_info = grass.vector_info(input)
    # check for wild mixture of vector types
    if in_info["points"] > 0 and in_info["boundaries"] > 0:
        grass.fatal(
            _(
                "The input vector map contains both polygons and points,"
                " cannot handle mixed types"
            )
        )

    pid = os.getpid()
    # process points via triangulation, then exit
    if in_info["points"] > 0:
        point = True
        layer = 1  # hardcoded for now
        out_temp = "{inp}_point_tmp_{pid}".format(inp=input_name, pid=pid)
        if method == "delaunay":
            grass.message(
                _("Processing point data (%d points found)...") % in_info["points"]
            )
            grass.run_command(
                "v.delaunay", input=input, layer=layer, output=out_temp, quiet=quiet
            )

        grass.run_command("v.db.addtable", map=out_temp, quiet=True)
        input = out_temp
        in_info = grass.vector_info(input)

    # process areas
    if in_info["areas"] == 0 and in_info["boundaries"] == 0:
        grass.fatal(_("The input vector map does not contain polygons"))

    out_type = "{inp}_type_{pid}".format(inp=input_name, pid=pid)
    input_tmp = "{inp}_tmp_{pid}".format(inp=input_name, pid=pid)
    remove_names = "%s,%s" % (out_type, input_tmp)
    grass.message(_("Processing area data (%d areas found)...") % in_info["areas"])

    try:
        grass.run_command(
            "v.category",
            layer="2",
            type="boundary",
            option="add",
            input=input,
            out=input_tmp,
            quiet=quiet,
        )
    except CalledModuleError:
        grass.run_command(
            "g.remove", flags="f", type="vector", name=input_tmp, quiet=quiet
        )
        grass.fatal(_("Error creating layer 2"))
    try:
        grass.run_command("v.db.addtable", map=input_tmp, layer="2", quiet=quiet)
    except CalledModuleError:
        grass.run_command(
            "g.remove", flags="f", type="vector", name=input_tmp, quiet=quiet
        )
        grass.fatal(_("Error creating new table for layer 2"))
    try:
        grass.run_command(
            "v.to.db",
            map=input_tmp,
            option="sides",
            columns="left,right",
            layer="2",
            quiet=quiet,
        )
    except CalledModuleError:
        grass.run_command(
            "g.remove", flags="f", type="vector", name=input_tmp, quiet=quiet
        )
        grass.fatal(_("Error populating new table for layer 2"))
    try:
        grass.run_command(
            "v.type",
            input=input_tmp,
            output=out_type,
            from_type="boundary",
            to_type="line",
            quiet=quiet,
            layer="2",
        )
    except CalledModuleError:
        grass.run_command(
            "g.remove", flags="f", type="vector", name=remove_names, quiet=quiet
        )
        grass.fatal(_("Error converting polygon to line"))
    report = grass.read_command(
        "v.category", flags="g", input=out_type, option="report", quiet=quiet
    )
    report = decode(report).split("\n")
    for r in report:
        if r.find("centroid") != -1:
            min_cat = report[0].split()[-2]
            max_cat = report[0].split()[-1]
            break
    if min_cat and max_cat:
        try:
            grass.run_command(
                "v.edit",
                map=out_type,
                tool="delete",
                type="centroid",
                layer=2,
                quiet=quiet,
                cats="{mi}-{ma}".format(mi=min_cat, ma=max_cat),
            )
        except CalledModuleError:
            grass.run_command(
                "g.remove", flags="f", type="vector", name=remove_names, quiet=quiet
            )
            grass.fatal(_("Error removing centroids"))

    try:
        try:
            # TODO: fix magic numbers for layer here and there
            grass.run_command(
                "v.db.droptable", map=out_type, layer=1, flags="f", quiet=True
            )
        except CalledModuleError:
            grass.run_command(
                "g.remove", flags="f", type="vector", name=remove_names, quiet=quiet
            )
            grass.fatal(_("Error removing table from layer 1"))
    # TODO: when this except is happaning, it seems that never, so it seems wrong
    except:
        grass.warning(_("No table for layer %d" % 1))
    try:
        grass.run_command(
            "v.category",
            input=out_type,
            option="transfer",
            output=output,
            layer="2,1",
            quiet=quiet,
            overwrite=overwrite,
        )
    except CalledModuleError:
        grass.run_command(
            "g.remove", flags="f", type="vector", name=remove_names, quiet=quiet
        )
        grass.fatal(_("Error adding categories"))
    grass.run_command(
        "g.remove", flags="f", type="vector", name=remove_names, quiet=quiet
    )
    if point:
        grass.run_command(
            "g.remove", flags="f", type="vector", name=out_temp, quiet=quiet
        )


if __name__ == "__main__":
    options, flags = grass.parser()
    main()