lightspeed

//// Deterministic async data engine and enterprise driver harness for M48.

import gleam/int
import gleam/list
import lightspeed/integration/async_driver

pub const snapshot_version = 1

/// M48 conformance scenarios.
pub type Scenario {
  AsyncDriverContractsConsistency
  EnterpriseDriverConformance
  TimeoutRetryTelemetryParity
  HeavyDataMixedLatencyBenchmarks
  CapabilityMatrixDeterminism
}

/// One M48 scenario outcome.
pub type ScenarioOutcome {
  ScenarioOutcome(
    scenario: Scenario,
    passed: Bool,
    deterministic: Bool,
    signature: String,
  )
}

/// Full M48 report.
pub type Report {
  Report(
    outcomes: List(ScenarioOutcome),
    failed_scenarios: Int,
    nondeterministic_failures: Int,
  )
}

/// Run all M48 scenarios.
pub fn run_matrix() -> Report {
  let outcomes =
    [
      AsyncDriverContractsConsistency,
      EnterpriseDriverConformance,
      TimeoutRetryTelemetryParity,
      HeavyDataMixedLatencyBenchmarks,
      CapabilityMatrixDeterminism,
    ]
    |> list.map(run_scenario)

  Report(
    outcomes: outcomes,
    failed_scenarios: count_failed(outcomes),
    nondeterministic_failures: count_nondeterministic(outcomes),
  )
}

/// Run one M48 scenario twice and require deterministic parity.
pub fn run_scenario(scenario: Scenario) -> ScenarioOutcome {
  let #(first_passed, first_signature) = evaluate(scenario)
  let #(second_passed, second_signature) = evaluate(scenario)
  let deterministic =
    first_passed == second_passed && first_signature == second_signature
  let passed = first_passed && second_passed && deterministic

  ScenarioOutcome(
    scenario: scenario,
    passed: passed,
    deterministic: deterministic,
    signature: first_signature,
  )
}

/// Scenario label.
pub fn scenario_label(scenario: Scenario) -> String {
  case scenario {
    AsyncDriverContractsConsistency -> "async_driver_contracts_consistency"
    EnterpriseDriverConformance -> "enterprise_driver_conformance"
    TimeoutRetryTelemetryParity -> "timeout_retry_telemetry_parity"
    HeavyDataMixedLatencyBenchmarks -> "heavy_data_mixed_latency_benchmarks"
    CapabilityMatrixDeterminism -> "capability_matrix_determinism"
  }
}

/// Stable pass/fail label.
pub fn pass_fail_label(outcome: ScenarioOutcome) -> String {
  case outcome.passed {
    True -> "pass"
    False -> "fail"
  }
}

/// Scenario signature accessor.
pub fn signature(outcome: ScenarioOutcome) -> String {
  outcome.signature
}

/// Scenario accessor.
pub fn scenario(outcome: ScenarioOutcome) -> Scenario {
  outcome.scenario
}

/// Determinism accessor.
pub fn deterministic(outcome: ScenarioOutcome) -> Bool {
  outcome.deterministic
}

/// Report outcomes accessor.
pub fn outcomes(report: Report) -> List(ScenarioOutcome) {
  report.outcomes
}

/// Failed scenario count.
pub fn failed_scenarios(report: Report) -> Int {
  report.failed_scenarios
}

/// Nondeterministic scenario count.
pub fn nondeterministic_failures(report: Report) -> Int {
  report.nondeterministic_failures
}

/// Stable report signature.
pub fn report_signature(report: Report) -> String {
  let entries =
    list.map(report.outcomes, fn(outcome) {
      scenario_label(outcome.scenario)
      <> "="
      <> pass_fail_label(outcome)
      <> ":deterministic="
      <> bool_label(outcome.deterministic)
      <> ":"
      <> outcome.signature
    })

  join_with(";", entries)
}

/// Deterministic snapshot signature for M48 fixture drift gates.
pub fn snapshot_signature() -> String {
  "m48.snapshot.v"
  <> int.to_string(snapshot_version)
  <> "|"
  <> report_signature(run_matrix())
}

/// Deterministic markdown report for M48 fixture scripts.
pub fn snapshot_report_markdown() -> String {
  let report = run_matrix()
  let failed = failed_scenarios(report)
  let nondeterministic = nondeterministic_failures(report)
  let status = case failed == 0 && nondeterministic == 0 {
    True -> "OK"
    False -> "FAIL"
  }

  "# Async Engine Fixture Report\n\n"
  <> "snapshot_version: "
  <> int.to_string(snapshot_version)
  <> "\n"
  <> "status: "
  <> status
  <> "\n"
  <> "failed_scenarios: "
  <> int.to_string(failed)
  <> "\n"
  <> "nondeterministic_failures: "
  <> int.to_string(nondeterministic)
  <> "\n\n"
  <> "snapshot_signature: "
  <> snapshot_signature()
  <> "\n\n"
  <> "report_signature: "
  <> report_signature(report)
  <> "\n"
}

fn evaluate(scenario: Scenario) -> #(Bool, String) {
  case scenario {
    AsyncDriverContractsConsistency ->
      evaluate_async_driver_contracts_consistency()
    EnterpriseDriverConformance -> evaluate_enterprise_driver_conformance()
    TimeoutRetryTelemetryParity -> evaluate_timeout_retry_telemetry_parity()
    HeavyDataMixedLatencyBenchmarks ->
      evaluate_heavy_data_mixed_latency_benchmarks()
    CapabilityMatrixDeterminism -> evaluate_capability_matrix_determinism()
  }
}

fn evaluate_async_driver_contracts_consistency() -> #(Bool, String) {
  let drivers = async_driver.supported_drivers()
  let passed = async_driver.contracts_consistent() && list.length(drivers) == 4
  let signature =
    "count="
    <> int.to_string(list.length(drivers))
    <> "|matrix="
    <> async_driver.capability_matrix_signature()

  #(passed, signature)
}

fn evaluate_enterprise_driver_conformance() -> #(Bool, String) {
  let drivers = async_driver.supported_drivers()
  let passed = all_drivers_valid(drivers)
  let signature =
    join_with(";", list.map(drivers, async_driver.driver_signature))

  #(passed, signature)
}

fn evaluate_timeout_retry_telemetry_parity() -> #(Bool, String) {
  let drivers = async_driver.supported_drivers()
  let passed = async_driver.timeout_retry_telemetry_parity()
  let signature =
    join_with(
      ";",
      list.map(drivers, fn(driver) {
        async_driver.name(driver)
        <> "|telemetry="
        <> telemetry_signature(async_driver.telemetry(driver))
      }),
    )

  #(passed, signature)
}

fn evaluate_heavy_data_mixed_latency_benchmarks() -> #(Bool, String) {
  let benchmarks = async_driver.run_enterprise_benchmarks()
  let budgets = async_driver.default_budgets()
  let results = async_driver.evaluate_budgets(benchmarks, budgets)
  let passed = async_driver.budget_failures(results) == 0
  let signature =
    "benchmarks="
    <> join_with(";", list.map(benchmarks, async_driver.benchmark_signature))
    <> "|budget_results="
    <> join_with(";", list.map(results, async_driver.budget_result_signature))

  #(passed, signature)
}

fn evaluate_capability_matrix_determinism() -> #(Bool, String) {
  let first = async_driver.capability_matrix_signature()
  let second = async_driver.capability_matrix_signature()
  let passed = first == second

  #(passed, first)
}

fn telemetry_signature(profile: async_driver.TelemetryProfile) -> String {
  profile.timeout_metric
  <> ","
  <> profile.retry_metric
  <> ","
  <> profile.latency_metric
  <> ","
  <> profile.in_flight_metric
}

fn all_drivers_valid(drivers: List(async_driver.DriverContract)) -> Bool {
  case drivers {
    [] -> True
    [driver, ..rest] -> async_driver.valid(driver) && all_drivers_valid(rest)
  }
}

fn count_failed(outcomes: List(ScenarioOutcome)) -> Int {
  case outcomes {
    [] -> 0
    [outcome, ..rest] ->
      case outcome.passed {
        True -> count_failed(rest)
        False -> 1 + count_failed(rest)
      }
  }
}

fn count_nondeterministic(outcomes: List(ScenarioOutcome)) -> Int {
  case outcomes {
    [] -> 0
    [outcome, ..rest] ->
      case outcome.deterministic {
        True -> count_nondeterministic(rest)
        False -> 1 + count_nondeterministic(rest)
      }
  }
}

fn bool_label(value: Bool) -> String {
  case value {
    True -> "true"
    False -> "false"
  }
}

fn join_with(separator: String, values: List(String)) -> String {
  case values {
    [] -> ""
    [value] -> value
    [value, ..rest] -> value <> separator <> join_with(separator, rest)
  }
}