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

require "json"

MARKER_FILE = "coverage/coverage.json"

unless File.exist?(MARKER_FILE)
  puts "Coverage check failed: no coverage.json found."
  puts "Please run `bin/linters/nplus1` or `bin/coverage` first to generate the report."
  exit 1
end

begin
  data = JSON.parse(File.read(MARKER_FILE))

  unless data.key?("groups")
    puts "Coverage check failed: 'groups' key not found in coverage.json format."
    exit(1)
  end

  failed_groups = []

  data["groups"].each do |group_name, group_data|
    # Depending on SimpleCov format, it might be nested under `lines`
    # Check both structured formats.
    percent = group_data.dig("lines", "covered_percent") || group_data["covered_percent"]

    if percent.nil?
      puts "Coverage check failed: Could not determine covered_percent for group '#{group_name}'."
      exit(1)
    end

    if percent < 100.0
      failed_groups << { name: group_name, percent: percent }
    end
  end

  if failed_groups.any?
    puts "Coverage check failed: Not all groups have 100% coverage."
    puts "The following groups need more tests:"
    failed_groups.sort_by { |fg| fg[:name] }.each do |fg|
      # Format percentage to 2 decimal places max
      percent_str = fg[:percent] == fg[:percent].to_i ? fg[:percent].to_i : format("%.2f", fg[:percent])
      puts " - #{fg[:name]}: #{percent_str}%"
    end

    if data["coverage"]
      puts "\nUncovered lines:"
      data["coverage"].each do |file, file_data|
        next unless file_data["lines"]
        next if file_data["lines"].compact.all? { |l| l.to_i > 0 }

        lines = file_data["lines"]
        missing_lines = []

        lines.each_with_index do |visits, idx|
          missing_lines << (idx + 1) if visits && visits.to_i == 0
        end

        if missing_lines.any?
          relative_file = file.sub(%r{^#{Regexp.escape(Dir.pwd)}/}, "")
          puts " - #{relative_file}: #{missing_lines.count} missing lines (#{missing_lines.join(", ")})"
        end
      end
    end

    exit(1)
  end

  puts "Coverage check passed: All groups have 100% coverage."
  exit(0)
rescue JSON::ParserError
  puts "Coverage check failed: coverage.json is not valid JSON."
  exit(1)
end