#!/usr/bin/env ruby
# frozen_string_literal: true

# Merges multiple SimpleCov result sets in .resultset.json into a single
# combined entry. This is necessary because Skunk (via RubyCritic) reads
# only the FIRST entry from the resultset, missing coverage data from
# other parallel test groups.
# It also synchronously formats the final coverage to avoid parallel test
# race conditions corrupting coverage/coverage.json

require "simplecov"
require "json"

RESULTSET_PATH = File.expand_path("../../..", __dir__) + "/coverage/.resultset.json"

unless File.exist?(RESULTSET_PATH)
  warn "[merge_coverage] No .resultset.json found"
  exit 0
end

data = JSON.parse(File.read(RESULTSET_PATH))
suite_count = data.keys.reject { |k| k == "merged" || k.include?(",") }.size

# Run standard collation which generates coverage/coverage.json perfectly
SimpleCov.collate(Dir[RESULTSET_PATH], "rails") do
  add_filter "/spec/"
  add_filter "/config/"
  add_filter "/vendor/"

  add_group "Channels", "app/channels"
  add_group "Controllers", "app/controllers"
  add_group "Models", "app/models"
  add_group "MCP Tools", "app/mcp"
  add_group "Helpers", "app/helpers"
  add_group "Jobs", "app/jobs"
  add_group "Services", "app/services"

  if ENV["COVERAGE_FORMAT"] == "json"
    require "simplecov_json_formatter"
    formatter SimpleCov::Formatter::JSONFormatter
  else
    formatter SimpleCov::Formatter::HTMLFormatter
  end
end

# Now clean up .resultset.json so that Skunk parses it correctly.
# SimpleCov.collate joined all command names into a single massive key.
# We extract that largest merged value, and rewrite .resultset.json with ONLY "merged"
new_data = JSON.parse(File.read(RESULTSET_PATH))
# Find the collated key (it will contain commas since it joined multiple suite names, or it will be the most recently touched)
merged_payload = new_data.values.max_by { |v| v["timestamp"].to_i }

File.write(RESULTSET_PATH, JSON.generate({ "merged" => merged_payload }))

puts "[merge_coverage] Merged #{suite_count > 0 ? suite_count : 1} suites into single entry"