#!/usr/bin/env python3
#
# Copyright (C) 2024 Simon Howard
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2 of the License, or (at your
# option) any later version. This program is distributed in the hope that
# it will be useful, but WITHOUT ANY WARRANTY; without even the implied
# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#

from glob import glob
import os
from os.path import dirname, basename, exists, join
import shlex
import sys
import yaml

def escape_filename(filename):
    return filename.replace("#", "\\#")

def read_config(path):
    if path == '':
        return {}

    # Config deeper in the hierarchy can override config files from
    # higher up in the hierarchy:
    result = read_config(dirname(path))
    config_file = join(path, ".democonfig")
    if exists(config_file):
        with open(config_file) as f:
            result.update(yaml.safe_load(f))

    return result

class Rule:
    def __init__(self, expect_file):
        self.out_file = expect_file.replace("expected/", "output/")
        self.lmp_file = (
            expect_file.replace("expected/", "demos/")
                       .replace(".txt", ".lmp"))
        self.cfg = read_config(self.lmp_file)

    def wads(self):
        yield join("iwads", self.cfg["iwad"])
        pwad = self.cfg.get("pwad")
        if pwad is not None:
            yield join("extract", pwad)

    def dependencies(self):
        yield self.lmp_file
        yield "$(SOURCE_PORT)"
        yield from self.wads()

        deh = self.cfg.get("deh")
        if deh is not None:
            yield join("extract", deh)

    def game_arguments(self):
        result = [
            "$(DOOMOPTS)",
            "-statdump", "$@",
            "-iwad", join("iwads", self.cfg["iwad"]),
            "-timedemo", "$<"
        ]

        if "extra_args" in self.cfg:
            result.extend(shlex.split(self.cfg["extra_args"]))

        if "deh" in self.cfg:
            result.extend(("-deh", join("extract", self.cfg["deh"])))

        if "gameversion" in self.cfg:
            result.extend(("-gameversion", self.cfg["gameversion"]))

        if "pwad" in self.cfg:
            result.extend(("-merge", join("extract", self.cfg["pwad"])))

        return result

    def command(self):
        args = self.game_arguments()
        return "$(SOURCE_PORT) " + " ".join(args) + " >/dev/null 2>&1"

    def rule_output(self):
        result = "%s: %s\n" % (
            escape_filename(self.out_file), " ".join(
                escape_filename(f) for f in self.dependencies()),
        )
        result += "\t@mkdir -p %s\n" % (shlex.quote(dirname(self.out_file)))
        result += "\t%s || true\n\n" % self.command()
        return result

depends_file = sys.argv[1]
rules = []
all_wads = set()

with open(depends_file, "w") as f:
    for filename in sorted(glob("expected/**/*.txt", recursive=True)):
        r = Rule(filename)
        f.write(r.rule_output())
        all_wads = all_wads | set(r.wads())

    f.write("wads: %s\n" % shlex.join(all_wads))