# frozen_string_literal: true

require "open3"
require "time"
require_relative "errors_formatter"
require_relative "source_file_formatter"

module SimpleCov
  module Formatter
    class JSONFormatter
      # Builds the hash that JSONFormatter serializes to coverage.json:
      # meta, per-file coverage data, group totals, and aggregate stats.
      class ResultHashFormatter
        # Bump SCHEMA_VERSION (and SCHEMA_URL) when the JSON shape
        # changes. Additive changes bump the minor segment, removals or
        # shape changes bump the major segment. The versioned file at
        # schemas/coverage-vX.Y.schema.json is the canonical artifact
        # consumers should pin to, schemas/coverage.schema.json is a
        # convenience alias that always tracks the latest. See the
        # `coverage.json` schema section of the README for the rationale.
        SCHEMA_VERSION = "1.0"
        SCHEMA_URL = "https://raw.githubusercontent.com/simplecov-ruby/simplecov/main/schemas/coverage-v#{SCHEMA_VERSION}.schema.json".freeze
        private_constant :SCHEMA_VERSION, :SCHEMA_URL

        def initialize(result, include_source: true)
          @result = result
          @include_source = include_source
        end

        def format
          {
            :$schema => SCHEMA_URL,
            :meta => format_meta,
            :total => format_coverage_statistics(@result.coverage_statistics),
            :coverage => format_files,
            :groups => format_groups,
            :errors => ErrorsFormatter.new(@result).call
          }
        end

      private

        def format_files
          @result.files.to_h do |source_file|
            [source_file.project_filename, SourceFileFormatter.new(source_file, include_source: @include_source).call]
          end
        end

        def format_groups
          @result.groups.to_h do |name, file_list|
            stats = format_coverage_statistics(file_list.coverage_statistics)
            [name, stats.merge(files: file_list.map(&:project_filename))]
          end
        end

        def format_meta
          {
            schema_version: SCHEMA_VERSION,
            simplecov_version: SimpleCov::VERSION,
            command_name: @result.command_name,
            project_name: SimpleCov.project_name,
            timestamp: @result.created_at.iso8601(3),
            root: SimpleCov.root,
            commit: git_commit,
            primary_coverage: SimpleCov.primary_coverage.to_s
          }.merge!(coverage_flags)
        end

        # Full git commit SHA of `SimpleCov.root`'s HEAD, or nil when the
        # project isn't a git checkout or git isn't on PATH. Recorded so tools
        # can recover the exact source a report was generated against, which
        # matters most when `source_in_json false` drops the source text from
        # coverage.json. stderr is captured (not forwarded) so a non-git project
        # doesn't print git's diagnostics to the build.
        def git_commit
          output, status = Open3.capture2e("git", "-C", SimpleCov.root.to_s, "rev-parse", "HEAD")
          status.success? ? output.strip : nil
        rescue StandardError
          nil
        end

        def coverage_flags
          {
            line_coverage: line_coverage_enabled?,
            branch_coverage: SimpleCov.branch_coverage?,
            method_coverage: SimpleCov.method_coverage?
          }
        end

        # Mirrors SourceFileFormatter's predicate so meta.line_coverage
        # tracks exactly which configurations cause the formatter to
        # emit line stats.
        def line_coverage_enabled?
          SimpleCov.coverage_criterion_enabled?(:line) || SimpleCov.coverage_criterion_enabled?(:oneshot_line)
        end

        def format_coverage_statistics(statistics)
          result = {} #: Hash[Symbol, untyped]
          result[:lines]    = format_line_statistic(statistics[:line])      if statistics[:line]
          result[:branches] = format_single_statistic(statistics[:branch])  if statistics[:branch]
          result[:methods]  = format_single_statistic(statistics[:method])  if statistics[:method]
          result
        end

        def format_line_statistic(stat)
          {
            covered: stat.covered,
            missed: stat.missed,
            omitted: stat.omitted,
            total: stat.total,
            percent: stat.percent,
            strength: stat.strength
          }
        end

        def format_single_statistic(stat)
          {
            covered: stat.covered,
            missed: stat.missed,
            total: stat.total,
            percent: stat.percent,
            strength: stat.strength
          }
        end
      end
    end
  end
end
