#!/usr/bin/env vpython3

# Copyright 2024 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""The entry of the metric system."""

from typing import List, Set

from measure import Measure
from test_script_metrics_pb2 import TestScriptMetrics


class Metric:
    def __init__(self) -> None:
        # A list of Measure to dump.
        self._metrics: List[Measure] = []
        # A list of tags to suffix the dumped results; see tag and dump function.
        self._tags: Set[str] = set()

    def register(self, metric: Measure) -> None:
        self._metrics.append(metric)

    def size(self) -> int:
        return len(self._metrics)

    def clear(self) -> None:
        self._metrics.clear()
        self._tags.clear()

    def tag(self, *args: str) -> None:
        # Tags the metrics, the tags will be merged and split by '|' and set to each
        # metric for easy selection.
        # This is an easy and hacky solution before adding output properties from
        # test script becomes possible. Currently adding output properties is
        # limited to the scope of the recipe, so any runtime tags are pretty much
        # impossible.
        self._tags.update(list(args))

    def dump(self) -> TestScriptMetrics:
        result = TestScriptMetrics()
        merged_tag = ''
        if self._tags:
            merged_tag = '|'
            for tag in sorted(self._tags):
                merged_tag += tag + '|'
        for m in self._metrics:
            metric = m.dump()
            metric.tag = merged_tag
            result.metrics.append(metric)
        return result