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

require "rubygems"
require "bundler"
Bundler.setup(:default, :development)

require "json"
require "optparse"
require "pathname"
require "time"
require "yaml"
require "httpx"
require "active_support/all"

require_relative "support/github_actions_failures"

GITHUB_API_OPENPROJECT_PREFIX = "https://api.github.com/repos/opf/openproject"
RAILS_ROOT = Pathname.new(__dir__).dirname
TEST_WORKFLOW_FILE = "test-core.yml"
PRIMARY_BRANCH_PATTERN = /\A(?:dev|release\/.+)\z/
TEST_STEP_NAMES = ["Unit tests", "Feature tests"].freeze
DEFAULT_TIMEZONE = "Europe/Berlin"
DEFAULT_LOOKBACK_DAYS = 30

module OutOfHoursCiFailures
  RunSummary = Data.define(:run_id, :run_number, :html_url, :head_branch, :event, :created_at, :failed_steps, :errors)
  SpecSummary = Data.define(
    :location,
    :test_types,
    :out_of_hours_count,
    :in_hours_count,
    :branches,
    :first_seen_at,
    :last_seen_at,
    :out_of_hours_runs,
    :in_hours_runs,
    :classification
  )

  class Options
    DEFAULTS = {
      days: DEFAULT_LOOKBACK_DAYS,
      include_pr_runs: false,
      json: false,
      timezone: DEFAULT_TIMEZONE,
      workflow: TEST_WORKFLOW_FILE
    }.freeze

    class << self
      # rubocop:disable Metrics/AbcSize
      def parse!(argv)
        options = DEFAULTS.dup

        OptionParser.new do |parser|
          parser.banner = "Usage: script/report_out_of_hours_ci_failures [options]"

          parser.on("--days DAYS", Integer, "Look back this many days (default: #{DEFAULT_LOOKBACK_DAYS})") do |value|
            options[:days] = value
          end

          parser.on("--include-pr-runs", "Include pull_request runs in the report") do
            options[:include_pr_runs] = true
          end

          parser.on("--json", "Output JSON instead of a table") do
            options[:json] = true
          end

          parser.on(
            "--timezone NAME",
            "Timezone for the in-hours/out-of-hours classification (default: #{DEFAULT_TIMEZONE})"
          ) do |value|
            options[:timezone] = value
          end

          parser.on("--workflow FILE", "Workflow file name to inspect (default: #{TEST_WORKFLOW_FILE})") do |value|
            options[:workflow] = value
          end

          parser.on("-h", "--help", "Print this help") do
            puts parser
            exit
          end
        end.parse!(argv)

        options
      end
      # rubocop:enable Metrics/AbcSize
    end
  end

  class GithubClient
    def initialize(cache_dir:)
      @cache_dir = cache_dir
    end

    def workflow_runs(workflow_file:, page:)
      get_json("actions/workflows/#{workflow_file}/runs?status=completed&per_page=100&page=#{page}")
    end

    def jobs(run_id)
      get_json("actions/runs/#{run_id}/jobs")
    end

    def log(job_id)
      cached("job_#{job_id}.log") do
        get_http("actions/jobs/#{job_id}/logs")
      end
    end

    private

    def http
      @http ||= HTTPX
        .plugin(:follow_redirects)
        .with_headers(
          "Authorization" => "Bearer #{ENV.fetch('GITHUB_TOKEN')}"
        )
    end

    def github_url(path)
      path.start_with?("http") ? path : "#{GITHUB_API_OPENPROJECT_PREFIX}/#{path}"
    end

    def get_http(path)
      response = http.get(github_url(path))
      response.raise_for_status
      response.to_s
    end

    def get_json(path)
      JSON.parse(get_http(path))
    rescue HTTPX::HTTPError => e
      body = e.response.json
      raise "#{body['message']} (see #{body['documentation_url']})"
    end

    def cached(name)
      path = @cache_dir.join(name)
      return path.read if path.file?

      content = yield
      path.dirname.mkpath
      path.write(content)
      content
    end
  end

  class ReportBuilder
    def initialize(options:, client:)
      @options = options
      @client = client
      @timezone = ActiveSupport::TimeZone[options[:timezone]] || raise("Unknown timezone #{options[:timezone]}")
      @since = Time.current - options[:days].days
    end

    # rubocop:disable Metrics/AbcSize
    def build
      spec_runs = Hash.new { |hash, key| hash[key] = [] }

      each_relevant_run do |workflow_run, failed_jobs|
        logs = failed_jobs.map { |job| @client.log(job.fetch("id")) }
        scan_result = GithubActionsFailures::JobErrorsFinder.scan_logs(logs)
        next if scan_result.errors.empty?

        failed_steps = failed_jobs.flat_map { failing_test_steps(it) }.uniq.sort
        summary = RunSummary.new(
          run_id: workflow_run.fetch("id"),
          run_number: workflow_run.fetch("run_number"),
          html_url: workflow_run.fetch("html_url"),
          head_branch: workflow_run.fetch("head_branch"),
          event: workflow_run.fetch("event"),
          created_at: parse_time(workflow_run.fetch("created_at")),
          failed_steps:,
          errors: scan_result.errors.map(&:location).sort
        )

        summary.errors.each do |location|
          spec_runs[location] << summary
        end
      end

      spec_runs
        .sort_by { |location, _| location }
        .map { |location, runs| summarize(location, runs) }
        .sort_by { |summary| [-summary.out_of_hours_count, -summary.in_hours_count, summary.location] }
    end
    # rubocop:enable Metrics/AbcSize

    private

    # rubocop:disable Metrics/AbcSize
    def each_relevant_run
      page = 1
      done = false

      loop do
        response = @client.workflow_runs(workflow_file: @options[:workflow], page:)
        runs = response.fetch("workflow_runs")
        break if runs.empty?

        runs.each do |workflow_run|
          created_at = parse_time(workflow_run.fetch("created_at"))
          if created_at < @since
            done = true
            break
          end

          next unless include_run?(workflow_run)

          jobs = @client.jobs(workflow_run.fetch("id")).fetch("jobs")
          failed_jobs = jobs.select { test_job_failure?(it) }
          next if failed_jobs.empty?

          yield workflow_run, failed_jobs
        end

        page += 1
        break if done
      end
    end
    # rubocop:enable Metrics/AbcSize

    def include_run?(workflow_run)
      branch = workflow_run.fetch("head_branch")
      return false unless branch.match?(PRIMARY_BRANCH_PATTERN) || @options[:include_pr_runs]
      return false if workflow_run.fetch("event") == "pull_request" && !@options[:include_pr_runs]

      true
    end

    def test_job_failure?(job)
      job.fetch("conclusion") == "failure" && failing_test_steps(job).any?
    end

    def failing_test_steps(job)
      job
        .fetch("steps")
        .filter_map { |step| step["name"] if step["conclusion"] == "failure" && TEST_STEP_NAMES.include?(step["name"]) }
    end

    # rubocop:disable Metrics/AbcSize
    def summarize(location, runs)
      out_of_hours_runs, in_hours_runs = runs.partition { out_of_hours?(it.created_at) }
      branches = runs.map(&:head_branch).uniq.sort
      test_types = runs.flat_map(&:failed_steps).uniq.sort

      SpecSummary.new(
        location:,
        test_types:,
        out_of_hours_count: out_of_hours_runs.count,
        in_hours_count: in_hours_runs.count,
        branches:,
        first_seen_at: runs.min_by(&:created_at).created_at,
        last_seen_at: runs.max_by(&:created_at).created_at,
        out_of_hours_runs: out_of_hours_runs.map(&:html_url),
        in_hours_runs: in_hours_runs.map(&:html_url),
        classification: classify(out_of_hours_runs:, in_hours_runs:, branches:)
      )
    end
    # rubocop:enable Metrics/AbcSize

    def classify(out_of_hours_runs:, in_hours_runs:, branches:)
      total = out_of_hours_runs.count + in_hours_runs.count
      return "needs manual review" if total < 2
      return "likely regression" if branches.one?
      return "likely datetime-sensitive" if in_hours_runs.empty?

      ratio = out_of_hours_runs.count.to_f / total
      return "likely datetime-sensitive" if ratio >= 0.75 && branches.many?

      "likely generic flaky"
    end

    def out_of_hours?(time)
      local = time.in_time_zone(@timezone)
      local.saturday? || local.sunday? || local.hour < 9 || local.hour >= 18
    end

    def parse_time(value)
      Time.iso8601(value)
    end
  end

  class Formatter
    def initialize(timezone:)
      @timezone = timezone
    end

    def print(spec_summaries, json: false)
      json ? print_json(spec_summaries) : print_table(spec_summaries)
    end

    private

    # rubocop:disable Metrics/AbcSize
    def print_json(spec_summaries)
      puts JSON.pretty_generate(
        spec_summaries.map do |summary|
          {
            location: summary.location,
            test_types: summary.test_types,
            out_of_hours_count: summary.out_of_hours_count,
            in_hours_count: summary.in_hours_count,
            branches: summary.branches,
            first_seen_at: summary.first_seen_at.in_time_zone(@timezone).iso8601,
            last_seen_at: summary.last_seen_at.in_time_zone(@timezone).iso8601,
            classification: summary.classification,
            out_of_hours_runs: summary.out_of_hours_runs,
            in_hours_runs: summary.in_hours_runs
          }
        end
      )
    end
    # rubocop:enable Metrics/AbcSize

    # rubocop:disable Metrics/AbcSize
    def print_table(spec_summaries)
      puts [
        "Classification".ljust(26),
        "OOH".rjust(3),
        "IN".rjust(3),
        "Type".ljust(16),
        "Branches".ljust(18),
        "First seen".ljust(17),
        "Last seen".ljust(17),
        "Spec"
      ].join("  ")

      spec_summaries.each do |summary|
        puts [
          summary.classification.ljust(26),
          summary.out_of_hours_count.to_s.rjust(3),
          summary.in_hours_count.to_s.rjust(3),
          summary.test_types.join(",").ljust(16),
          truncate(summary.branches.join(","), 18).ljust(18),
          summary.first_seen_at.in_time_zone(@timezone).strftime("%F %H:%M"),
          summary.last_seen_at.in_time_zone(@timezone).strftime("%F %H:%M"),
          summary.location
        ].join("  ")
      end
    end
    # rubocop:enable Metrics/AbcSize

    def truncate(value, length)
      return value if value.length <= length

      "#{value[0, length - 3]}..."
    end
  end
end

if $PROGRAM_NAME == __FILE__
  if !ENV["GITHUB_TOKEN"]
    raise "Missing GITHUB_TOKEN env, go to https://github.com/settings/tokens and create one with 'repo' access"
  end

  # workaround an openssl 3.6.0 issue
  # https://github.com/ruby/openssl/issues/949#issuecomment-3367944960
  s = OpenSSL::X509::Store.new.tap(&:set_default_paths)
  OpenSSL::SSL::SSLContext.send(:remove_const, :DEFAULT_CERT_STORE) rescue nil # rubocop:disable Style/RescueModifier
  OpenSSL::SSL::SSLContext.const_set(:DEFAULT_CERT_STORE, s.freeze)

  options = OutOfHoursCiFailures::Options.parse!(ARGV)
  client = OutOfHoursCiFailures::GithubClient.new(cache_dir: RAILS_ROOT.join("tmp/report_out_of_hours_ci_failures"))
  builder = OutOfHoursCiFailures::ReportBuilder.new(options:, client:)
  formatter = OutOfHoursCiFailures::Formatter.new(timezone: options[:timezone])

  formatter.print(builder.build, json: options[:json])
end