# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

# Write out event information for C++. The events are defined
# in a file provided as a command-line argument.

import itertools
import json
import sys
from collections import OrderedDict
from os import path

from mozparsers import parse_events
from mozparsers.shared_telemetry_utils import ParserError, static_assert

COMPONENTS_PATH = path.abspath(
    path.join(path.dirname(__file__), path.pardir, path.pardir)
)
sys.path.append(
    path.join(COMPONENTS_PATH, "glean", "build_scripts", "glean_parser_ext")
)
from string_table import StringTable

# The banner/text at the top of the generated file.
banner = """/* This file is auto-generated, only for internal use in TelemetryEvent.h,
   see gen_event_data.py. */
"""

file_header = """\
#ifndef mozilla_TelemetryEventData_h
#define mozilla_TelemetryEventData_h
#include "core/EventInfo.h"
#include "nsITelemetry.h"
namespace {
"""

file_footer = """\
} // namespace
#endif // mozilla_TelemetryEventData_h
"""


def write_extra_table(events, output, string_table):
    table_name = "gExtraKeysTable"
    extra_table = []
    extra_count = 0

    print("#if defined(_MSC_VER) && !defined(__clang__)", file=output)
    print("const uint32_t %s[] = {" % table_name, file=output)
    print("#else", file=output)
    print("constexpr uint32_t %s[] = {" % table_name, file=output)
    print("#endif", file=output)

    for e in events:
        extra_index = 0
        extra_keys = e.extra_keys
        if len(extra_keys) > 0:
            extra_index = extra_count
            extra_count += len(extra_keys)
            indexes = string_table.stringIndexes(extra_keys)

            print(
                "  // %s, [%s], [%s]"
                % (e.category, ", ".join(e.methods), ", ".join(e.objects)),
                file=output,
            )
            print("  // extra_keys: %s" % ", ".join(extra_keys), file=output)
            print("  %s," % ", ".join(map(str, indexes)), file=output)

        extra_table.append((extra_index, len(extra_keys)))

    print("};", file=output)
    static_assert(output, "sizeof(%s) <= UINT32_MAX" % table_name, "index overflow")

    return extra_table


def write_common_event_table(events, output, string_table, extra_table):
    table_name = "gCommonEventInfo"

    print("#if defined(_MSC_VER) && !defined(__clang__)", file=output)
    print("const CommonEventInfo %s[] = {" % table_name, file=output)
    print("#else", file=output)
    print("constexpr CommonEventInfo %s[] = {" % table_name, file=output)
    print("#endif", file=output)

    for e, extras in zip(events, extra_table):
        # Write a comment to make the file human-readable.
        print("  // category: %s" % e.category, file=output)
        print("  // methods: [%s]" % ", ".join(e.methods), file=output)
        print("  // objects: [%s]" % ", ".join(e.objects), file=output)

        # Write the common info structure
        print(
            "  {%d, %d, %d, %d, %s, %s, %s },"
            % (
                string_table.stringIndex(e.category),
                string_table.stringIndex(e.expiry_version),
                extras[0],  # extra keys index
                extras[1],  # extra keys count
                e.dataset,
                " | ".join(e.record_in_processes_enum),
                " | ".join(e.products_enum),
            ),
            file=output,
        )

    print("};", file=output)
    static_assert(output, "sizeof(%s) <= UINT32_MAX" % table_name, "index overflow")


def write_event_table(events, output, string_table):
    table_name = "gEventInfo"

    print("#if defined(_MSC_VER) && !defined(__clang__)", file=output)
    print("const EventInfo %s[] = {" % table_name, file=output)
    print("#else", file=output)
    print("constexpr EventInfo %s[] = {" % table_name, file=output)
    print("#endif", file=output)

    for common_info_index, e in enumerate(events):
        for method_name, object_name in itertools.product(e.methods, e.objects):
            print(
                "  // category: %s, method: %s, object: %s"
                % (e.category, method_name, object_name),
                file=output,
            )

            print(
                "  {gCommonEventInfo[%d], %d, %d},"
                % (
                    common_info_index,
                    string_table.stringIndex(method_name),
                    string_table.stringIndex(object_name),
                ),
                file=output,
            )

    print("};", file=output)
    static_assert(output, "sizeof(%s) <= UINT32_MAX" % table_name, "index overflow")


def generate_JSON_definitions(output, *filenames):
    """Write the event definitions to a JSON file.

    :param output: the file to write the content to.
    :param filenames: a list of filenames provided by the build system.
           We only support a single file.
    """
    # Load the event data.
    events = []
    for filename in filenames:
        try:
            batch = parse_events.load_events(filename, True)
            events.extend(batch)
        except ParserError as ex:
            print("\nError processing %s:\n%s\n" % (filename, str(ex)), file=sys.stderr)
            sys.exit(1)

    event_definitions = OrderedDict()
    for event in events:
        category = event.category

        if category not in event_definitions:
            event_definitions[category] = OrderedDict()

        event_definitions[category][event.name] = OrderedDict(
            {
                "methods": event.methods,
                "objects": event.objects,
                "extra_keys": event.extra_keys,
                "record_on_release": True
                if event.dataset_short == "opt-out"
                else False,
                # We don't expire dynamic-builtin scalars: they're only meant for
                # use in local developer builds anyway. They will expire when rebuilding.
                "expires": event.expiry_version,
                "expired": False,
                "products": event.products,
            }
        )

    json.dump(event_definitions, output, sort_keys=True)


def main(output, *filenames):
    # Load the event data.
    events = []
    for filename in filenames:
        try:
            batch = parse_events.load_events(filename, True)
            events.extend(batch)
        except ParserError as ex:
            print("\nError processing %s:\n%s\n" % (filename, str(ex)), file=sys.stderr)
            sys.exit(1)

    # Write the scalar data file.
    print(banner, file=output)
    print(file_header, file=output)

    # Write the extra keys table.
    string_table = StringTable()
    extra_table = write_extra_table(events, output, string_table)
    print("", file=output)

    # Write a table with the common event data.
    write_common_event_table(events, output, string_table, extra_table)
    print("", file=output)

    # Write the data for individual events.
    write_event_table(events, output, string_table)
    print("", file=output)

    # Write the string table.
    string_table_name = "gEventsStringTable"
    string_table.writeDefinition(output, string_table_name)
    static_assert(
        output, "sizeof(%s) <= UINT32_MAX" % string_table_name, "index overflow"
    )
    print("", file=output)

    print(file_footer, file=output)


if __name__ == "__main__":
    main(sys.stdout, *sys.argv[1:])