#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# ******************************************************************************
#
#  Project:  GDAL utils.auxiliary
#  Purpose:  an extended argparse.ArgumentParser to be used with all gdal-utils
#  Author:   Idan Miara <idan@miara.com>
#
# ******************************************************************************
#  Copyright (c) 2021, Idan Miara <idan@miara.com>
#
# SPDX-License-Identifier: MIT
# ******************************************************************************
import argparse
import os
import shlex
import sys
from abc import ABC, abstractmethod
from gettext import gettext
from warnings import warn


class ExtendAction(argparse.Action):
    def __call__(self, parser, namespace, values, option_string=None):
        items = getattr(namespace, self.dest) or []
        items.extend(values)
        setattr(namespace, self.dest, items)


class GDALArgumentParser(argparse.ArgumentParser):
    def __init__(
        self,
        title=None,
        description=None,
        formatter_class=None,
        fromfile_prefix_chars="@",
        disable_h_option: bool = False,
        add_gdal_generic_options: bool = False,
        **kwargs,
    ):
        if title:
            if not description:
                description = title
            else:
                if formatter_class is None:
                    formatter_class = argparse.RawDescriptionHelpFormatter
                description = f'{title}\n{"-"*(2+len(title))}\n{description}'

        if formatter_class is None:
            formatter_class = argparse.HelpFormatter

        super().__init__(
            fromfile_prefix_chars=fromfile_prefix_chars,
            description=description,
            formatter_class=formatter_class,
            add_help=not disable_h_option and not add_gdal_generic_options,
            **kwargs,
        )

        self.add_gdal_generic_options = add_gdal_generic_options
        if add_gdal_generic_options:
            if disable_h_option:
                self.add_argument(
                    "--help",
                    action="help",
                    default=argparse.SUPPRESS,
                    help=gettext("show this help message and exit"),
                )
            else:
                self.add_argument(
                    "--help",
                    "-h",
                    action="help",
                    default=argparse.SUPPRESS,
                    help=gettext("show this help message and exit"),
                )

            self.add_argument(
                "--help-general",
                action="store_true",
                default=argparse.SUPPRESS,
                help="Gives a brief usage message for the generic GDAL OGR command line options and exit",
            )

        if sys.version_info < (3, 8):
            # extend was introduced to the stdlib in Python 3.8
            self.register("action", "extend", ExtendAction)

        self.custom_format_arg = False

    def add_argument(self, *args, **kwargs):
        if "--format" in args:
            self.custom_format_arg = True
        return super().add_argument(*args, **kwargs)

    def parse_args(self, args=None, optfile_arg=None, **kwargs):

        if self.add_gdal_generic_options:
            from osgeo import gdal

            args_for_gdal_general = []
            post_args = []
            # gdal_calc has a --format switch whose semantics is not the
            # one of the generic --format
            if self.custom_format_arg and args:
                i = 0
                while i < len(args):
                    if args[i] == "--format":
                        post_args.append(args[i])
                        post_args.append(args[i + 1])
                        i += 1
                    else:
                        args_for_gdal_general.append(args[i])
                    i += 1
            else:
                args_for_gdal_general = args
            args = gdal.GeneralCmdLineProcessor(["dummy"] + args_for_gdal_general)
            if args is None:
                sys.exit(0)
            args = args[1:] + post_args

        if (
            args is not None
            and optfile_arg in args
            and self.fromfile_prefix_chars is not None
            and optfile_arg is not None
        ):

            # Replace '--optfile x' with the standard '@x'
            prefix = self.fromfile_prefix_chars[0]
            count = len(args)
            new_args = []
            i = 0
            while i < count:
                arg = args[i]
                if arg == optfile_arg:
                    if i == count - 1:
                        raise Exception(
                            f"Missing filename argument following {optfile_arg}: "
                        )
                    arg = prefix + args[i + 1]
                    warn(
                        f'"{optfile_arg} {args[i + 1]}" is deprecated. '
                        f'Please use "{arg}" instead.',
                        DeprecationWarning,
                    )
                    i += 1
                i += 1
                new_args.append(arg)
            args = new_args
        return super().parse_args(args=args, **kwargs)

    def convert_arg_line_to_args(self, arg_line):
        return shlex.split(arg_line, comments=True)


class GDALScript(ABC):
    def __init__(self, **kwargs):
        self.prog = None
        self.title = None
        self.description = None
        self.examples = None
        self.disable_h_option = False
        self.optfile_arg = None
        self._parser = None
        self.examples = []
        self.epilog = None
        self.kwargs = kwargs

    def add_example(self, title, arguments):
        example = (title, arguments)
        self.examples.append(example)

    @property
    def parser(self):
        if self._parser is None:
            self._parser = GDALArgumentParser(
                prog=self.prog,
                title=self.title,
                description=self.description,
                disable_h_option=self.disable_h_option,
                add_gdal_generic_options=True,
                epilog=self.get_epilog(),
                **self.kwargs,
            )
        return self._parser

    @parser.setter
    def parser(self, value):
        self._parser = value

    @abstractmethod
    def get_parser(self, argv) -> GDALArgumentParser:
        pass

    @abstractmethod
    def doit(self, **kwargs):
        pass

    def augment_kwargs(self, kwargs) -> dict:
        return kwargs

    def parse(self, argv) -> dict:
        parser = self.get_parser(argv)
        args = parser.parse_args(argv, optfile_arg=self.optfile_arg)
        kwargs = vars(args)
        kwargs = self.augment_kwargs(kwargs)
        return kwargs

    def main(self, argv) -> int:
        kwargs = self.parse(argv[1:])
        try:
            self.doit(**kwargs)
            return 0
        except IOError as e:
            print(str(e), file=sys.stderr)
            return 1
        except Exception:
            import traceback

            traceback.print_exc()
            return 1

    def get_epilog(self):
        prog = self.prog
        if prog is None:
            prog = os.path.basename(sys.argv[0])
        example_list = []
        for idx, (title, args) in enumerate(self.examples):
            example_list.append(f"example #{idx+1}: {title}\n{prog} {args}")
        epilog = "\n\n".join(example_list)
        if self.epilog:
            epilog = epilog + "\n\n" + self.epilog
        return epilog or None