import argparse
import collections
import json
import pathlib
import re
from typing import Dict, List, Union

import jinja2
import tomli
from jinja2 import BaseLoader, Environment
from semiwrap.makeplan import (
    BuildTarget,
    BuildTargetOutput,
    CppMacroValue,
    Entrypoint,
    ExtensionModule,
    LocalDependency,
    makeplan,
)
from semiwrap.pkgconf_cache import PkgconfCache
from semiwrap.pyproject import PyProject

from shared.bazel.rules.robotpy.generation_utils import (
    fixup_native_lib_name,
    fixup_python_dep_name,
    fixup_root_package_name,
    fixup_shared_lib_name,
)
from shared.bazel.rules.robotpy.hack_pkgcfgs import hack_pkgconfig


class HeaderToDatConfig:
    def __init__(self, header_to_dat_args: BuildTarget):
        includes = []
        defines = []

        idx = 0
        while True:
            if header_to_dat_args.args[idx] == "-I":
                includes.append(header_to_dat_args.args[idx + 1])
            elif header_to_dat_args.args[idx] == "-D":
                defines.append(header_to_dat_args.args[idx + 1])
            else:
                break
            idx += 2
        if header_to_dat_args.args[idx] == "--cpp":
            idx += 2

        args = header_to_dat_args.args[idx:]
        self.class_name = args[0]
        self.yml_file = args[1].path
        self.defines = defines

        def find_root_dir(include_root):
            """
            Somewhat naive attempt to find the "root" directory of the repository,
            as specified from the runfiles path
            """
            if "__main__/" in include_root:
                return pathlib.Path(
                    include_root[: include_root.find("__main__/") + len("__main__/")]
                )
            elif "_main/" in include_root:
                return pathlib.Path(
                    include_root[: include_root.find("_main/") + len("_main/")]
                )
            else:
                return pathlib.Path(include_root)

        include_root = str(args[3]).replace("\\", "/")
        root_dir = find_root_dir(include_root)
        if "native" in include_root:
            base_include_root = pathlib.Path(*args[3].relative_to(root_dir).parts[3:])
            base_include_file = args[2].relative_to(include_root)
            base_library = re.search("native/(.*?)/", include_root).groups(1)[0]

            self.include_file = f"$(execpath :{fixup_native_lib_name('robotpy-native-' + base_library)}.copy_headers)/{base_include_file}"
            self.include_root = f"$(execpath :{fixup_native_lib_name('robotpy-native-' + base_library)}.copy_headers)"
        else:
            if root_dir.is_absolute():
                self.include_file = args[2].relative_to(root_dir)
                self.include_root = args[3].relative_to(root_dir)
            else:
                self.include_file = args[2]
                self.include_root = args[3]
        # type casters         = 4
        # dat file             = 5
        # d file               = 6
        # compiler info        = 7

        self.templates = []
        self.trampolines = []

        args = args[8:]
        assert 0 == len(args)


class ResolveCastersConfig:
    def __init__(self, item: BuildTarget):
        self.pkl_file = item.args[0].name
        self.dep_file = item.args[1].name
        # semiwrap casters = 2
        self.caster_files = []
        caster_deps = set()

        for dep_path in item.args[3:]:
            if isinstance(dep_path, BuildTargetOutput):
                output_file = dep_path.target.args[2]
                caster_deps.add(
                    f":src/main/python/{dep_path.target.install_path}/{output_file.name}"
                )
            else:
                relevant_parts = dep_path.parts[3:]
                caster_deps.add(
                    f"//{relevant_parts[0]}:" + "/".join(relevant_parts[1:])
                )

        self.caster_deps = sorted(caster_deps)


class GenLibInitPyConfig:
    def __init__(self, item: BuildTarget):
        self.output_file = item.args[0].name
        self.modules = item.args[1:]
        self.install_path = item.install_path


class GenPkgConfConfig:
    def __init__(self, item: BuildTarget):
        self.module_pkg_name = item.args[0]
        self.pkg_name = item.args[1]
        self.project_file = item.args[2].path
        self.output_file = item.args[3].name
        # --libinit-py = 4
        self.libinit_py = item.args[5]

        assert 0 == len(item.args[6:])

        self.install_path = item.install_path


class GenModInitHpp:
    def __init__(self, item: BuildTarget):
        self.lib_name = item.args[0]
        self.output_file = item.args[1].name
        idx = 2
        while idx < len(item.args):
            if item.args[idx].command != "header2dat":
                break
            idx += 1

        assert 0 == len(item.args[idx:])


class PublishCastersConfig:
    def __init__(self, projectcfg, item: BuildTarget):
        self.project_file = item.args[0].path
        self.casters_name = item.args[1]
        self.json_output = item.args[2].name
        self.pc_output = item.args[3].name
        assert 0 == len(item.args[4:])

        self.install_path = item.install_path

        self.include_paths = []
        caster_cfg = projectcfg.export_type_casters[self.casters_name]

        for inc_dir in caster_cfg.includedir:
            self.include_paths.append(f"src/main/python/{inc_dir}")


class BazelExtensionModule:
    def __init__(
        self,
        extension_module: ExtensionModule,
        additional_extension_targets: Dict[str, BuildTarget],
    ):
        self.name = extension_module.name
        self.package_name = extension_module.package_name
        self.install_path = extension_module.install_path

        self.generation_data = self._extract_header_generation(extension_module.sources)
        self.resolve_casters = ResolveCastersConfig(
            additional_extension_targets["resolve-casters"]
        )
        self.gen_libinit = GenLibInitPyConfig(
            additional_extension_targets["gen-libinit-py"]
        )
        self.gen_pkgconf = GenPkgConfConfig(additional_extension_targets["gen-pkgconf"])
        self.gen_modinit = GenModInitHpp(
            additional_extension_targets["gen-modinit-hpp"]
        )

        self.pkgcache = PkgconfCache()

        all_dependencies = set()

        for d in extension_module.depends:
            if isinstance(d, LocalDependency):
                all_dependencies.add(d.name)
            self._collect_local_dependency_names(d, all_dependencies)

        native_wrapper_dependencies = set()
        local_extension_dependencies = set()
        dynamic_dependencies = set()
        for dep_name in all_dependencies:
            if "native" in dep_name:

                transitive_deps = set()
                self._get_transitive_native_dependencies(dep_name, transitive_deps)
                for d in transitive_deps:
                    if d == "robotpy-native-mrclib":
                        continue
                    base_library = fixup_root_package_name(
                        d.replace("robotpy-native-", "")
                    )
                    native_wrapper_dependencies.add(
                        f"//{base_library}:{fixup_native_lib_name(d)}.copy_headers"
                    )
            elif "-casters" in dep_name:
                base_library = dep_name.split("-")[0]
                local_extension_dependencies.add(f"//{base_library}:{dep_name}")
            else:
                base_library = fixup_root_package_name(dep_name.split("_")[0])
                local_extension_dependencies.add(
                    f"//{base_library}:{fixup_shared_lib_name(base_library)}"
                )
                dynamic_dependencies.add(
                    f"//{base_library}:shared/{fixup_shared_lib_name(base_library)}"
                )
                if dep_name != self.name:
                    local_extension_dependencies.add(
                        f"//{base_library}:{dep_name}_pybind_library"
                    )

        self.native_wrapper_dependencies = sorted(native_wrapper_dependencies)
        self.local_extension_dependencies = sorted(local_extension_dependencies)
        self.dynamic_dependencies = sorted(dynamic_dependencies)

    def get_defines(self):
        defines = set()
        for h2d_def in self.generation_data.values():
            defines.update(h2d_def.defines)
        return sorted(defines)

    def _get_transitive_native_dependencies(self, dep_name, transitive_deps):
        entry = self.pkgcache.get(dep_name)
        transitive_deps.add(dep_name)
        for req in entry.requires:
            if req not in transitive_deps:
                transitive_deps.add(req)
                self._get_transitive_native_dependencies(req, transitive_deps)

    def _collect_local_dependency_names(self, dep, all_dependencies):
        for child_dep in dep.depends:
            if isinstance(child_dep, str):
                if child_dep != "semiwrap":
                    all_dependencies.add(child_dep)
            elif isinstance(child_dep, LocalDependency):
                all_dependencies.add(child_dep.name)
                self._collect_local_dependency_names(child_dep, all_dependencies)
            else:
                raise

    def _extract_header_generation(self, sources) -> Dict[str, HeaderToDatConfig]:
        generation_data: Dict[str, HeaderToDatConfig] = {}

        def get_h2d_config(target_info: BuildTarget) -> HeaderToDatConfig:
            config = HeaderToDatConfig(target_info)
            if config.class_name not in generation_data:
                generation_data[config.class_name] = config
            return generation_data[config.class_name]

        for source in sources:
            if source.command == "dat2cpp":
                h2d_config = get_h2d_config(source.args[0])
            elif source.command == "dat2trampoline":
                h2d_config = get_h2d_config(source.args[0])
                name, out_file = source.args[1:]
                h2d_config.trampolines.append((name, out_file.name))
            elif source.command == "dat2tmplcpp":
                h2d_config = get_h2d_config(source.args[0])
                name, out_file = source.args[1:]
                h2d_config.templates.append((out_file.name[:-4], name))
            elif source.command == "dat2tmplhpp":
                # Handled by dat2tmplcpp
                continue
            elif source.command == "gen-modinit-hpp":
                # Handled elsewhere
                continue
            else:
                raise Exception("Unknown command", source.command)

        return generation_data


def generate_pybind_build_file(
    pkgcfgs: List[pathlib.Path],
    project_file: pathlib.Path,
    package_root_file: str,
    stripped_include_prefix: str,
    yml_prefix: Union[str, None],
    output_file: pathlib.Path,
):
    project_dir = project_file.parent
    plan = makeplan(project_dir)

    hack_pkgconfig(pkgcfgs)

    extension_modules = []
    entry_points = collections.defaultdict(list)

    pyproject = PyProject(project_file)
    projectcfg = pyproject.project

    # Cache built up for an extension module. Gets reset when an ExtensionModule is encountered
    additional_extension_targets: Dict[str, BuildTarget] = {}
    publish_casters_targets = []

    for item in plan:
        if isinstance(item, ExtensionModule):
            extension_modules.append(
                BazelExtensionModule(item, additional_extension_targets)
            )
            additional_extension_targets = {}
        elif isinstance(item, BuildTarget):
            if item.command in [
                "resolve-casters",
                "gen-libinit-py",
                "gen-pkgconf",
                "gen-modinit-hpp",
            ]:
                if item.command in additional_extension_targets:
                    raise Exception(f"Repeated target {item.command}")
                additional_extension_targets[item.command] = item
            elif item.command in [
                "header2dat",
                "dat2cpp",
                "dat2tmplcpp",
                "dat2tmplhpp",
                "dat2trampoline",
                "make-pyi",
            ]:
                pass
            elif item.command == "publish-casters":
                publish_casters_targets.append(PublishCastersConfig(projectcfg, item))
            else:
                raise Exception(f"Unhandled build target {item.command}")
        elif isinstance(item, Entrypoint):
            entry_points[item.group].append(f"{item.name} = {item.package}")
        elif isinstance(item, LocalDependency):
            pass
        elif isinstance(item, CppMacroValue):
            pass
        else:
            raise Exception(f"Unknown item {type(item)}")

    with open(project_file, "rb") as fp:
        raw_config = tomli.load(fp)

    try:
        top_level_name = raw_config["tool"]["hatch"]["build"]["targets"]["wheel"][
            "packages"
        ]
    except KeyError:
        top_level_name = [raw_config["project"]["name"]]
    assert len(top_level_name) == 1
    top_level_name = top_level_name[0]

    template_file = "shared/bazel/rules/robotpy/pybind_build_file_template.jinja2"
    with open(template_file, "r") as f:
        template_contents = f.read()

    def jsonify(item):
        if isinstance(item, jinja2.runtime.Undefined):
            return "None"
        return json.dumps(item)

    def target_from_python_dep(python_dep):
        if "native" in python_dep:
            base_library = python_dep.replace("robotpy-native-", "")
            return f"//{fixup_root_package_name(base_library)}:{fixup_python_dep_name(python_dep)}"
        else:
            base_library = python_dep.replace("robotpy-", "")
            return f"//{fixup_root_package_name(base_library)}:{fixup_python_dep_name(python_dep)}"

    EXTERNAL_PYPI_DEPS = [
        "robotpy-cli",
        "pytest-reraise",
        "pytest",
    ]

    python_deps = []
    has_external_python_deps = False
    if "dependencies" in raw_config["project"]:
        for d in raw_config["project"]["dependencies"]:
            for external_dep in EXTERNAL_PYPI_DEPS:
                if external_dep in d:
                    has_external_python_deps = True
                    python_deps.append(f'requirement("{external_dep}")')
                    break
            else:
                pd = target_from_python_dep(d.split("==")[0])
                python_deps.append(pd)

    env = Environment(loader=BaseLoader)
    env.filters["jsonify"] = jsonify
    template = env.from_string(template_contents)

    all_local_native_deps = set()
    for em in extension_modules:
        all_local_native_deps.update(em.native_wrapper_dependencies)
    all_local_native_deps = sorted(all_local_native_deps)

    try:
        version_file = raw_config["tool"]["hatch"]["build"]["hooks"]["robotpy"][
            "version_file"
        ]
    except:
        version_file = None

    # The entry points defined above are implicit to how the project is broken down in the toml files.
    # This adds potentially extra explicitly declared entry points
    if "entry-points" in raw_config["project"]:
        explicit_entry_points = raw_config["project"]["entry-points"]
        for entry_point_type in explicit_entry_points:
            for ep_key, ep_value in explicit_entry_points[entry_point_type].items():
                entry_points[entry_point_type].append(f"{ep_key} = {ep_value}")

    strip_path_prefixes = [
        f"{fixup_root_package_name(top_level_name)}/{stripped_include_prefix}",
        f"{fixup_root_package_name(top_level_name)}",
    ]

    with open(output_file, "w") as f:
        f.write(
            template.render(
                extension_modules=extension_modules,
                top_level_name=top_level_name,
                publish_casters_targets=publish_casters_targets,
                python_deps=sorted(python_deps),
                all_local_native_deps=all_local_native_deps,
                stripped_include_prefix=stripped_include_prefix,
                strip_path_prefixes=strip_path_prefixes,
                yml_prefix=yml_prefix,
                package_root_file=package_root_file,
                raw_project_config=raw_config["project"],
                entry_points=entry_points,
                version_file=version_file,
                has_external_python_deps=has_external_python_deps,
            )
            + "\n"
        )


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("--project_file", type=pathlib.Path, required=True)
    parser.add_argument("--output_file", type=pathlib.Path, required=True)
    parser.add_argument(
        "--stripped_include_prefix", type=str, default="src/main/python"
    )
    parser.add_argument("--yml_prefix", type=str)
    parser.add_argument("--package_root_file", type=str)
    parser.add_argument("--pkgcfgs", type=pathlib.Path, nargs="+")

    args = parser.parse_args()

    generate_pybind_build_file(
        args.pkgcfgs,
        args.project_file,
        args.package_root_file,
        args.stripped_include_prefix,
        args.yml_prefix,
        args.output_file,
    )


if __name__ == "__main__":
    main()