#!/usr/bin/env python3
# Copyright 2020-2022, Collabora, Ltd.
# SPDX-License-Identifier: BSL-1.0
"""Generate code from a JSON file describing interaction profiles and
bindings."""

import argparse
import json



class PathsByLengthCollector:
    """Helper class to sort paths by length, useful for creating fast path
    validation functions.
    """

    def __init__(self):
        self.by_length = dict()

    def add_path(self, path):
        length = len(path)
        if length in self.by_length:
            self.by_length[length].add(path)
        else:
            self.by_length[length] = {path}

    def add_paths(self, paths):
        for path in paths:
            self.add_path(path)

    def to_dict_of_lists(self):
        ret = dict()
        for length, set_per_length in self.by_length.items():
            ret[length] = list(set_per_length)
        return ret

class Component:
    """Components correspond with the standard OpenXR components click, touch, force, value, x, y, twist, pose
    """

    @classmethod
    def parse_components(component_cls,
                         subaction_path,
                         identifier_path,
                         json_subpath):
        """Turn a Identifier's component paths into a list of Component objects."""

        component_list = []
        for component_name in json_subpath["components"]:  # click, touch, ...
            monado_binding = None
            if component_name in json_subpath["monado_bindings"]:
                monado_binding = json_subpath["monado_bindings"][component_name]

            c = Component(subaction_path,
                          identifier_path,
                          json_subpath["localized_name"],
                          json_subpath["type"],
                          component_name,
                          monado_binding,
                          json_subpath["components"])
            component_list.append(c)

        return component_list

    def __init__(self,
                 subaction_path,
                 identifier_path,
                 subpath_localized_name,
                 subpath_type,
                 component_name,
                 monado_binding,
                 components_for_subpath):
        self.subaction_path = subaction_path
        self.identifier_path = identifier_path  # note: starts with a slash
        self.subpath_localized_name = subpath_localized_name
        self.subpath_type = subpath_type
        self.component_name = component_name
        self.monado_binding = monado_binding

        # click, touch etc. components under the subpath of this component. Only needed for steamvr profile gen.
        self.components_for_subpath = components_for_subpath

    def get_full_openxr_paths(self):
        """A group of paths that derive from the same component.
        For example .../thumbstick, .../thumbstick/x, .../thumbstick/y
        """
        paths = []

        basepath = self.subaction_path + self.identifier_path

        if self.component_name == "position":
            paths.append(basepath + "/" + "x")
            paths.append(basepath + "/" + "y")
            paths.append(basepath)
        else:
            paths.append(basepath + "/" + self.component_name)
            paths.append(basepath)

        return paths

    def is_input(self):
        # only haptics is output so far, everything else is input
        return self.component_name != "haptic"

    def is_output(self):
        return not self.is_input()


class Identifer:
    """A Identifier is a OpenXR identifier with a user path, such as button
    X, a trackpad, a pose such as aim. It can have one or more features, even
    tho outputs doesn't include a component/feature path a output indentifier
    will have a haptic output feature.
    """

    @classmethod
    def parse_identifiers(indentifer_cls, json_profile):
        """Turn a profile's input paths into a list of Component objects."""

        json_subaction_paths = json_profile["subaction_paths"]
        json_subpaths = json_profile["subpaths"]

        identifier_list = []
        for subaction_path in json_subaction_paths:  # /user/hand/*
            for json_sub_path_itm in json_subpaths.items():  # /input/*, /output/*
                identifier_path = json_sub_path_itm[0]  # /input/trackpad
                json_subpath = json_sub_path_itm[1]  # json object associated with a subpath (type, localized_name, ...)

                # Oculus Touch a,b/x,y components only exist on one controller
                if "side" in json_subpath and "/user/hand/" + json_subpath["side"] != subaction_path:
                    continue

                component_list = Component.parse_components(subaction_path,
                                                            identifier_path,
                                                            json_subpath)

                i = Identifer(subaction_path,
                              identifier_path,
                              component_list)
                identifier_list.append(i)

        return identifier_list

    def __init__(self,
                 subaction_path,
                 identifier_path,
                 component_list):
        self.subaction_path = subaction_path
        self.identifier_path = identifier_path
        self.path = subaction_path + identifier_path
        self.components = component_list
        return


class Profile:
    """An interactive bindings profile."""

    def __init__(self, profile_name, json_profile):
        """Construct an profile."""
        self.name = profile_name
        self.localized_name = json_profile['title']
        self.profile_type = json_profile["type"]
        self.monado_device_enum = json_profile["monado_device"]
        self.validation_func_name = profile_name.replace("/interaction_profiles/", "").replace("/", "_")
        self.identifiers = Identifer.parse_identifiers(json_profile)

        self.components = []
        for identifier in self.identifiers:
            for component in identifier.components:
                self.components.append(component)

        collector = PathsByLengthCollector()
        for component in self.components:
            collector.add_paths(component.get_full_openxr_paths())
        self.by_length = collector.to_dict_of_lists()


class Bindings:
    """A collection of interaction profiles used in bindings."""

    @classmethod
    def parse(cls, json_root):
        """Parse an entire bindings.json into a collection of Profile objects."""
        return cls(json_root)

    @classmethod
    def load_and_parse(cls, file):
        """Load a JSON file and parse it into Profile objects."""
        with open(file) as infile:
            json_root = json.loads(infile.read())
            return cls.parse(json_root)

    def __init__(self, json_root):
        """Construct a bindings from a dictionary of profiles."""
        self.profiles = [Profile(profile_name, json_profile) for
                         profile_name, json_profile in json_root["profiles"].items()]


header = '''// Copyright 2020, Collabora, Ltd.
// SPDX-License-Identifier: BSL-1.0
/*!
 * @file
 * @brief  {brief}.
 * @author Jakob Bornecrantz <jakob@collabora.com>
 * @author Christoph Haag <christoph.haag@collabora.com>
 * @ingroup {group}
 */
'''

func_start = '''
bool
oxr_verify_{func}_subpath(const char *str, size_t length)
{{
\tswitch (length) {{
'''

if_strcmp = '''if (strcmp(str, "{check}") == 0) {{
\t\t\treturn true;
\t\t}} else '''


def generate_bindings_c(file, p):
    """Generate the file to verify subpaths on a interaction profile."""
    f = open(file, "w")
    f.write(header.format(brief='Generated bindings data', group='oxr_main'))
    f.write('''
#include "b_generated_bindings.h"
#include <string.h>

// clang-format off
''')

    for profile in p.profiles:
        f.write(func_start.format(func=profile.validation_func_name))
        for length in profile.by_length:
            f.write("\tcase " + str(length) + ":\n\t\t")
            for path in profile.by_length[length]:
                f.write(if_strcmp.format(check=path))
            f.write("{\n\t\t\treturn false;\n\t\t}\n")
        f.write("\tdefault:\n\t\treturn false;\n\t}\n}\n")

    f.write(
        f'\n\nstruct profile_template profile_templates[{len(p.profiles)}] = {{ // array of profile_template\n')
    for profile in p.profiles:
        hw_name = str(profile.name.split("/")[-1])
        vendor_name = str(profile.name.split("/")[-2])
        fname = vendor_name + "_" + hw_name + "_profile.json"
        controller_type = "monado_" + vendor_name + "_" + hw_name

        binding_count = len(profile.components)
        f.write(f'\t{{ // profile_template\n')
        f.write(f'\t\t.name = {profile.monado_device_enum},\n')
        f.write(f'\t\t.path = "{profile.name}",\n')
        f.write(f'\t\t.localized_name = "{profile.localized_name}",\n')
        f.write(f'\t\t.steamvr_input_profile_path = "{fname}",\n')
        f.write(f'\t\t.steamvr_controller_type = "{controller_type}",\n')
        f.write(f'\t\t.binding_count = {binding_count},\n')
        f.write(
            f'\t\t.bindings = (struct binding_template[]){{ // array of binding_template\n')

        component: Component
        for idx, component in enumerate(profile.components):

            steamvr_path = component.identifier_path
            if component.component_name in ["click", "touch", "force", "value"]:
                steamvr_path += "/" + component.component_name

            f.write(f'\t\t\t{{ // binding_template {idx}\n')
            f.write(f'\t\t\t\t.subaction_path = "{component.subaction_path}",\n')
            f.write(f'\t\t\t\t.steamvr_path = "{steamvr_path}",\n')
            f.write(
                f'\t\t\t\t.localized_name = "{component.subpath_localized_name}",\n')

            f.write('\t\t\t\t.paths = { // array of paths\n')
            for path in component.get_full_openxr_paths():
                f.write(f'\t\t\t\t\t"{path}",\n')
            f.write('\t\t\t\t\tNULL\n')
            f.write('\t\t\t\t}, // /array of paths\n')

            # print("component", component.__dict__)

            component_str = component.component_name

            # controllers can have input that we don't have bindings for
            if component.monado_binding:
                monado_binding = component.monado_binding

                if component.is_input() and monado_binding is not None:
                    f.write(f'\t\t\t\t.input = {monado_binding},\n')
                else:
                    f.write(f'\t\t\t\t.input = 0,\n')

                if component.is_output() and monado_binding is not None:
                    f.write(f'\t\t\t\t.output = {monado_binding},\n')
                else:
                    f.write(f'\t\t\t\t.output = 0,\n')

            f.write(f'\t\t\t}}, // /binding_template {idx}\n')

        f.write('\t\t}, // /array of binding_template\n')
        f.write('\t}, // /profile_template\n')

    f.write('}; // /array of profile_template\n\n')

    inputs = set()
    outputs = set()
    for profile in p.profiles:
        component: Component
        for idx, component in enumerate(profile.components):

            if not component.monado_binding:
                continue

            if component.subpath_type == "vibration":
                outputs.add(component.monado_binding)
            else:
                inputs.add(component.monado_binding)

    # special cased bindings that are never directly used in the input profiles
    inputs.add("XRT_INPUT_GENERIC_HEAD_POSE")
    inputs.add("XRT_INPUT_GENERIC_HEAD_DETECT")
    inputs.add("XRT_INPUT_GENERIC_HAND_TRACKING_LEFT")
    inputs.add("XRT_INPUT_GENERIC_HAND_TRACKING_RIGHT")
    inputs.add("XRT_INPUT_GENERIC_TRACKER_POSE")

    f.write('const char *\n')
    f.write('xrt_input_name_string(enum xrt_input_name input)\n')
    f.write('{\n')
    f.write('\tswitch(input)\n')
    f.write('\t{\n')
    for input in inputs:
        f.write(f'\tcase {input}: return "{input}";\n')
    f.write(f'\tdefault: return "UNKNOWN";\n')
    f.write('\t}\n')
    f.write('}\n')

    f.write('enum xrt_input_name\n')
    f.write('xrt_input_name_enum(const char *input)\n')
    f.write('{\n')
    for input in inputs:
        f.write(f'\tif(strcmp("{input}", input) == 0) return {input};\n')
    f.write(f'\treturn XRT_INPUT_GENERIC_TRACKER_POSE;\n')
    f.write('}\n')

    f.write('const char *\n')
    f.write('xrt_output_name_string(enum xrt_output_name output)\n')
    f.write('{\n')
    f.write('\tswitch(output)\n')
    f.write('\t{\n')
    for output in outputs:
        f.write(f'\tcase {output}: return "{output}";\n')
    f.write(f'\tdefault: return "UNKNOWN";\n')
    f.write('\t}\n')
    f.write('}\n')

    f.write('enum xrt_output_name\n')
    f.write('xrt_output_name_enum(const char *output)\n')
    f.write('{\n')
    for output in outputs:
        f.write(f'\tif(strcmp("{output}", output) == 0) return {output};\n')
    f.write(f'\treturn XRT_OUTPUT_NAME_SIMPLE_VIBRATION;\n')
    f.write('}\n')

    f.write("\n// clang-format on\n")

    f.close()


def generate_bindings_h(file, p):
    """Generate header for the verify subpaths functions."""
    f = open(file, "w")
    f.write(header.format(brief='Generated bindings data header',
                          group='oxr_api'))
    f.write('''
#pragma once

#include <stddef.h>

#include "xrt/xrt_defines.h"

// clang-format off
''')

    for profile in p.profiles:
        f.write("\nbool\noxr_verify_" + profile.validation_func_name +
                "_subpath(const char *str, size_t length);\n")

    f.write(f'''
#define PATHS_PER_BINDING_TEMPLATE 8

struct binding_template
{{
\tconst char *subaction_path;
\tconst char *steamvr_path;
\tconst char *localized_name;
\tconst char *paths[PATHS_PER_BINDING_TEMPLATE];
\tenum xrt_input_name input;
\tenum xrt_output_name output;
}};

struct profile_template
{{
\tenum xrt_device_name name;
\tconst char *path;
\tconst char *localized_name;
\tconst char *steamvr_input_profile_path;
\tconst char *steamvr_controller_type;
\tstruct binding_template *bindings;
\tsize_t binding_count;
}};

#define NUM_PROFILE_TEMPLATES {len(p.profiles)}
extern struct profile_template profile_templates[NUM_PROFILE_TEMPLATES];

''')

    f.write('const char *\n')
    f.write('xrt_input_name_string(enum xrt_input_name input);\n\n')

    f.write('enum xrt_input_name\n')
    f.write('xrt_input_name_enum(const char *input);\n\n')

    f.write('const char *\n')
    f.write('xrt_output_name_string(enum xrt_output_name output);\n\n')

    f.write('enum xrt_output_name\n')
    f.write('xrt_output_name_enum(const char *output);\n\n')

    f.write("\n// clang-format on\n")
    f.close()


def main():
    """Handle command line and generate a file."""
    parser = argparse.ArgumentParser(description='Bindings generator.')
    parser.add_argument(
        'bindings', help='Bindings file to use')
    parser.add_argument(
        'output', type=str, nargs='+',
        help='Output file, uses the name to choose output type')
    args = parser.parse_args()

    bindings = Bindings.load_and_parse(args.bindings)

    for output in args.output:
        if output.endswith("generated_bindings.c"):
            generate_bindings_c(output, bindings)
        if output.endswith("generated_bindings.h"):
            generate_bindings_h(output, bindings)


if __name__ == "__main__":
    main()