defmodule Mix.Tasks.Raxol.Bench.Advanced do
  @moduledoc """
  Advanced benchmarking commands leveraging the new world-class infrastructure.

  ## Commands

    mix raxol.bench.advanced suite           # Run registered benchmark suites
    mix raxol.bench.advanced compare         # Compare with competitors
    mix raxol.bench.advanced regression      # Detailed regression analysis
    mix raxol.bench.advanced profile         # Deep profiling with flame graphs
    mix raxol.bench.advanced continuous      # Continuous monitoring mode
    mix raxol.bench.advanced report          # Generate comprehensive reports
    mix raxol.bench.advanced analyze         # Statistical analysis of results

  ## Options

    --suite NAME           Run specific benchmark suite
    --tags TAG1,TAG2      Filter scenarios by tags
    --baseline VERSION    Compare against specific baseline
    --threshold PERCENT   Regression threshold (default: 5%)
    --format FORMAT       Output format (text|json|html|markdown)
    --output FILE         Save results to file
    --iterations N        Number of iterations for statistical significance
    --confidence LEVEL    Confidence level for tests (default: 0.95)
    --competitor NAME     Compare against specific competitor
    --realtime           Show results in realtime
    --verbose            Verbose output
  """

  use Mix.Task

  alias Raxol.Benchmark.{
    CompetitorSuite,
    RegressionDetector,
    StatisticalAnalyzer,
    SuiteRegistry
  }

  alias Raxol.Core.Runtime.Log

  @shortdoc "Advanced benchmarking with statistical analysis"

  @switches [
    suite: :string,
    tags: :string,
    baseline: :string,
    threshold: :float,
    format: :string,
    output: :string,
    iterations: :integer,
    confidence: :float,
    competitor: :string,
    realtime: :boolean,
    verbose: :boolean,
    help: :boolean
  ]

  @spec run(list()) :: no_return()
  def run(args) do
    {opts, commands, _} = OptionParser.parse(args, switches: @switches)

    handle_help_option(opts)
    setup_benchmark_environment()
    execute_command(commands, opts)
  end

  defp handle_help_option(opts) do
    if opts[:help] do
      print_help()
      System.halt(0)
    end
  end

  defp setup_benchmark_environment do
    Mix.Task.run("app.start")
    # Start the suite registry
    {:ok, _pid} = SuiteRegistry.start_link()
  end

  defp execute_command(commands, opts) do
    command_handler = get_command_handler(commands)

    case command_handler do
      nil ->
        handle_unknown_command(commands)

      handler ->
        handler.(opts)
    end
  end

  defp get_command_handler(commands) do
    command_map = %{
      ["suite"] => &run_suite_benchmarks/1,
      ["compare"] => &run_competitor_comparison/1,
      ["regression"] => &run_regression_analysis/1,
      ["profile"] => &run_profiling_session/1,
      ["continuous"] => &run_continuous_monitoring/1,
      ["report"] => &generate_comprehensive_report/1,
      ["analyze"] => &run_statistical_analysis/1,
      ["discover"] => &discover_and_run_suites/1
    }

    Map.get(command_map, commands)
  end

  defp handle_unknown_command(commands) do
    Mix.shell().error("Unknown command: #{Enum.join(commands, " ")}")
    print_help()
  end

  # Command implementations

  defp run_suite_benchmarks(opts) do
    Mix.shell().info("[FAST] Running Benchmark Suites...")

    # Discover available suites
    {:ok, count} = SuiteRegistry.discover_suites()
    Mix.shell().info("Discovered #{count} benchmark suites")

    # Filter suites based on options
    filter = build_suite_filter(opts)

    # Run the suites
    {:ok, results} =
      SuiteRegistry.run_suites(filter, build_benchmark_config(opts))

    # Analyze results
    analysis = analyze_suite_results(results)

    # Generate output
    output_results(analysis, opts)

    # Check for regressions if baseline specified
    if opts[:baseline] do
      check_regressions(results, opts[:baseline], opts)
    end
  end

  defp run_competitor_comparison(opts) do
    Mix.shell().info("[POWER] Running Competitor Comparison...")

    competitor = opts[:competitor] || "all"
    Mix.shell().info("Comparing against: #{competitor}")

    # Run competitor benchmarks
    results = CompetitorSuite.run_benchmarks()

    # Generate comparison report
    comparison = CompetitorSuite.generate_comparison_report(results)

    # Calculate performance scores
    scores = CompetitorSuite.calculate_performance_score(results)

    # Output results
    output_competitor_comparison(comparison, scores, opts)
  end

  defp run_regression_analysis(opts) do
    Mix.shell().info("[STATS] Running Regression Analysis...")

    # Load current and baseline results
    current = load_latest_results()
    baseline = load_baseline_results(opts[:baseline] || "latest")

    if current && baseline do
      # Perform regression detection
      threshold = opts[:threshold] || 0.05

      detection =
        RegressionDetector.detect(current, baseline, threshold: threshold)

      # Generate detailed report
      report =
        RegressionDetector.generate_report(detection,
          format: opts[:format] || :text
        )

      # Output report
      output_regression_report(report, detection, opts)

      # Exit with error code if regressions found
      if length(detection.regressions) > 0 do
        Mix.shell().error("[FAIL] Performance regressions detected!")
        System.halt(1)
      else
        Mix.shell().info("[OK] No performance regressions detected")
      end
    else
      Mix.shell().error("Unable to load benchmark results for comparison")
      System.halt(1)
    end
  end

  defp run_profiling_session(opts) do
    Mix.shell().info("[SEARCH] Running Profiling Session...")

    suite = opts[:suite] || "all"

    # Start profiling
    _ = :fprof.start()
    _ = :fprof.trace([:start])

    # Run benchmarks with profiling enabled
    results = run_with_profiling(suite, opts)

    # Stop profiling
    _ = :fprof.trace([:stop])
    _ = :fprof.profile()
    _ = :fprof.analyse(dest: ~c"profile_output.txt")

    # Generate flame graph if available
    if System.find_executable("flamegraph.pl") do
      generate_flame_graph()
    end

    # Analyze profiling results
    profile_analysis = analyze_profile_output()

    # Output results
    output_profiling_results(profile_analysis, results, opts)
  end

  defp run_continuous_monitoring(opts) do
    Mix.shell().info("[TREND] Starting Continuous Monitoring...")

    # Default: 1 minute
    interval = opts[:interval] || 60_000

    # Start monitoring loop
    spawn(fn ->
      loop_continuous_monitoring(interval, opts)
    end)

    Mix.shell().info("Monitoring started. Press Ctrl+C to stop.")

    # Keep the process running
    :timer.sleep(:infinity)
  end

  defp generate_comprehensive_report(opts) do
    Mix.shell().info("[DOC] Generating Comprehensive Report...")

    # Load all available results
    results = load_all_results()

    # Perform comprehensive analysis
    analysis = %{
      statistical: perform_statistical_analysis(results),
      trends: analyze_performance_trends(results),
      comparison: compare_with_competitors(results),
      regression: detect_historical_regressions(results),
      recommendations: generate_recommendations(results)
    }

    # Generate report in requested format
    format = String.to_atom(opts[:format] || "html")
    report = generate_report(analysis, format)

    # Save report
    output_file = opts[:output] || "benchmark_report_#{timestamp()}.#{format}"
    File.write!(output_file, report)

    Mix.shell().info("Report generated: #{output_file}")
  end

  defp run_statistical_analysis(opts) do
    Mix.shell().info("[STAT] Running statistical analysis")

    # Load results
    results = load_latest_results()

    if results do
      # Extract time series data
      time_data = extract_time_series(results)

      # Perform statistical analysis
      analysis = StatisticalAnalyzer.analyze(time_data)

      # Calculate advanced metrics
      advanced = %{
        percentiles: analysis.percentiles,
        outliers: analysis.outliers,
        distribution: analysis.distribution,
        confidence_intervals: analysis.confidence_intervals,
        statistical_tests: perform_statistical_tests(time_data, opts)
      }

      # Output analysis
      output_statistical_analysis(advanced, opts)
    else
      Mix.shell().error("No results available for analysis")
    end
  end

  defp discover_and_run_suites(opts) do
    Mix.shell().info("[DISC] Discovering and running benchmark suites")

    # Discover all available suites
    {:ok, count} = SuiteRegistry.discover_suites()
    Mix.shell().info("Found #{count} benchmark suites")

    # List discovered suites
    suites = SuiteRegistry.list_suites()

    Enum.each(suites, fn suite ->
      Mix.shell().info("  • #{suite.name} (#{suite.scenario_count} scenarios)")
    end)

    # Run all discovered suites
    if Mix.shell().yes?("Run all discovered suites?") do
      {:ok, results} = SuiteRegistry.run_all(build_benchmark_config(opts))
      output_results(results, opts)
    end
  end

  # Helper functions

  defp build_suite_filter(opts) do
    filter = []

    filter =
      if opts[:suite] do
        Keyword.put(filter, :names, [opts[:suite]])
      else
        filter
      end

    filter =
      if opts[:tags] do
        tags = String.split(opts[:tags], ",") |> Enum.map(&String.to_atom/1)
        Keyword.put(filter, :tags, tags)
      else
        filter
      end

    filter
  end

  defp build_benchmark_config(opts) do
    config = [
      time: opts[:time] || 5,
      memory_time: opts[:memory_time] || 2,
      warmup: opts[:warmup] || 1,
      parallel: opts[:parallel] || 1
    ]

    config =
      if opts[:iterations] do
        Keyword.put(config, :iterations, opts[:iterations])
      else
        config
      end

    config
  end

  defp analyze_suite_results(results) do
    results
    |> Enum.map(fn {suite, data} ->
      {suite,
       %{
         statistics: calculate_statistics(data),
         performance: analyze_performance(data),
         memory: analyze_memory(data)
       }}
    end)
    |> Enum.into(%{})
  end

  defp calculate_statistics(data) do
    times = extract_execution_times(data)
    StatisticalAnalyzer.analyze(times)
  end

  defp analyze_performance(data) do
    # Performance analysis logic
    %{
      average_time: calculate_average(data),
      throughput: calculate_throughput(data),
      latency: calculate_latency(data)
    }
  end

  defp analyze_memory(data) do
    # Memory analysis logic
    %{
      peak_memory: calculate_peak_memory(data),
      average_memory: calculate_average_memory(data),
      allocations: count_allocations(data)
    }
  end

  defp output_results(results, opts) do
    format = String.to_atom(opts[:format] || "text")

    output =
      case format do
        :json -> Jason.encode!(results, pretty: true)
        :html -> generate_html_output(results)
        :markdown -> generate_markdown_output(results)
        _ -> generate_text_output(results)
      end

    if opts[:output] do
      File.write!(opts[:output], output)
      Mix.shell().info("Results saved to: #{opts[:output]}")
    else
      Log.info(output)
    end
  end

  defp output_competitor_comparison(comparison, scores, _opts) do
    Mix.shell().info("\n=== Competitor Comparison Results ===\n")

    print_performance_ranking(comparison.performance_ranking)
    print_raxol_score(scores.raxol_score)
    print_relative_performance(scores.comparison)
  end

  defp print_performance_ranking(performance_ranking) do
    Mix.shell().info("Performance Ranking:")

    Enum.each(performance_ranking, &print_ranking_entry/1)
  end

  defp print_ranking_entry(%{rank: rank, test: test, time: time}) do
    Mix.shell().info("  #{rank}. #{test}: #{Float.round(time, 2)}μs")
  end

  defp print_raxol_score(raxol_score) do
    Mix.shell().info(
      "\nRaxol Performance Score: #{Float.round(raxol_score, 1)}/100"
    )
  end

  defp print_relative_performance(comparison_data) do
    Mix.shell().info("\nRelative Performance vs Competitors:")

    Enum.each(comparison_data, &print_comparison_entry/1)
  end

  defp print_comparison_entry({terminal, data}) do
    percentage = Float.round(data.relative_performance, 1)
    symbol = get_performance_symbol(percentage)

    Mix.shell().info("  #{symbol} vs #{terminal}: #{percentage}%")
  end

  defp get_performance_symbol(percentage) do
    cond do
      percentage > 110 -> "[FAST]"
      percentage > 100 -> "[OK]"
      percentage > 90 -> "[WARN]"
      true -> "[FAIL]"
    end
  end

  defp load_latest_results do
    # Load the most recent benchmark results
    case File.ls("bench/results") do
      {:ok, files} ->
        latest_file =
          files
          |> Enum.filter(&String.ends_with?(&1, ".benchee"))
          |> Enum.sort()
          |> List.last()

        if latest_file do
          # TODO: Implement proper benchee result loading
          # Benchee doesn't have a direct load function for saved files
          # Need to use custom deserialization
          {:ok, Path.join("bench/results", latest_file)}
        end

      _ ->
        nil
    end
  end

  defp load_baseline_results(version) do
    # Load baseline results for comparison
    baseline_file = "bench/baselines/#{version}.benchee"

    if File.exists?(baseline_file) do
      # TODO: Implement proper benchee result loading
      # Benchee doesn't have a direct load function for saved files
      # Need to use custom deserialization
      {:ok, baseline_file}
    else
      nil
    end
  end

  defp check_regressions(results, baseline_version, opts) do
    baseline = load_baseline_results(baseline_version)

    if baseline do
      threshold = opts[:threshold] || 0.05

      detection =
        RegressionDetector.detect(results, baseline, threshold: threshold)

      if length(detection.regressions) > 0 do
        print_regressions(detection.regressions)
      end
    end
  end

  defp print_regressions(regressions) do
    Mix.shell().error("\n[WARN]  Performance Regressions Detected:")

    Enum.each(regressions, fn reg ->
      Mix.shell().error(
        "  • #{reg.scenario}: +#{Float.round(reg.percent_change, 1)}% (#{reg.severity})"
      )
    end)
  end

  defp loop_continuous_monitoring(interval, opts) do
    # Run benchmarks
    {:ok, results} = SuiteRegistry.run_all(build_benchmark_config(opts))

    # Analyze results
    analysis = analyze_suite_results(results)

    # Display summary
    display_monitoring_summary(analysis)

    # Check for anomalies
    check_for_anomalies(analysis)

    # Sleep and repeat
    :timer.sleep(interval)
    loop_continuous_monitoring(interval, opts)
  end

  defp display_monitoring_summary(analysis) do
    timestamp = DateTime.utc_now() |> DateTime.to_string()
    Mix.shell().info("\n[#{timestamp}] Monitoring Update:")

    Enum.each(analysis, fn {suite, data} ->
      avg_time = get_in(data, [:statistics, :mean]) || 0
      p99 = get_in(data, [:statistics, :percentiles, :p99]) || 0

      Mix.shell().info(
        "  #{suite}: avg=#{Float.round(avg_time, 2)}μs, p99=#{Float.round(p99, 2)}μs"
      )
    end)
  end

  defp check_for_anomalies(analysis) do
    Enum.each(analysis, fn {suite, data} ->
      outliers = get_in(data, [:statistics, :outliers, :outliers]) || []

      if length(outliers) > 0 do
        Mix.shell().warn(
          "  [WARN]  #{suite}: #{length(outliers)} outliers detected"
        )
      end
    end)
  end

  defp generate_text_output(results) do
    Enum.map_join(results, "\n", fn {suite, data} ->
      """
      Suite: #{suite}
      ================
      Mean: #{Float.round(get_in(data, [:statistics, :mean]) || 0, 2)}μs
      Median: #{Float.round(get_in(data, [:statistics, :median]) || 0, 2)}μs
      P95: #{Float.round(get_in(data, [:statistics, :percentiles, :p95]) || 0, 2)}μs
      P99: #{Float.round(get_in(data, [:statistics, :percentiles, :p99]) || 0, 2)}μs
      """
    end)
  end

  defp generate_html_output(_results) do
    # Generate HTML report
    "<html><body><h1>Benchmark Results</h1></body></html>"
  end

  defp generate_markdown_output(results) do
    # Generate Markdown report
    Enum.map_join(results, "\n", fn {suite, _data} ->
      "## #{suite}\n\nResults pending...\n"
    end)
  end

  defp timestamp do
    DateTime.utc_now()
    |> DateTime.to_iso8601()
    |> String.replace(~r/[:\.]/, "_")
  end

  defp print_help do
    Mix.shell().info(@moduledoc)
  end

  # Stub implementations for complex functions
  defp extract_execution_times(_data), do: [1.0, 2.0, 3.0]
  defp calculate_average(_data), do: 2.0
  defp calculate_throughput(_data), do: 1000.0
  defp calculate_latency(_data), do: 1.0
  defp calculate_peak_memory(_data), do: 100_000
  defp calculate_average_memory(_data), do: 50_000
  defp count_allocations(_data), do: 1000
  defp load_all_results, do: %{}
  defp perform_statistical_analysis(_results), do: %{}
  defp analyze_performance_trends(_results), do: %{}
  defp compare_with_competitors(_results), do: %{}
  defp detect_historical_regressions(_results), do: %{}
  defp generate_recommendations(_results), do: []
  defp generate_report(_analysis, _format), do: ""
  defp extract_time_series(_results), do: []
  defp perform_statistical_tests(_data, _opts), do: %{}
  defp output_statistical_analysis(_analysis, _opts), do: :ok
  defp output_regression_report(_report, _detection, _opts), do: :ok
  defp run_with_profiling(_suite, _opts), do: %{}
  defp generate_flame_graph, do: :ok
  defp analyze_profile_output, do: %{}
  defp output_profiling_results(_analysis, _results, _opts), do: :ok
end
