import { describe, expect, it, vi } from "vitest";

import { createContractHttpExecutor } from "../../src/adapters/http/http-execution-v3.ts";
import type {
  HttpExecutionObservation,
} from "../../src/adapters/http/http-execution-v3.ts";
import { createHttpObservationProjector } from "../../src/bootstrap/runtime-adapters.ts";
import { createReferenceFeatureInstalledInput } from "../../src/features/reference-feature/adapters/create-reference-feature-input.ts";
import {
  DIAGNOSTIC_CONTEXT_ALLOWLIST,
  projectDiagnosticRecord,
  type DiagnosticRecordInput,
} from "../../src/contracts/diagnostics.ts";
import {
  projectTelemetryEvent,
  type TelemetryEventName,
} from "../../src/contracts/telemetry.ts";
import {
  TEST_CREATE_HTTP_CONTRACT,
  TEST_LIST_HTTP_CONTRACT,
} from "../helpers/external-contract-fixture.ts";

const ROUTE_ID = "TEST_ROUTE";

function scopeSnapshot(isCurrent: () => boolean = () => true) {
  return Object.freeze({
    generation: 1,
    fingerprint: "scope-1",
    identities: Object.freeze({}) as never,
    signal: new AbortController().signal,
    isCurrent,
  });
}

type RecordedDiagnostic = DiagnosticRecordInput;
type RecordedTelemetry = Readonly<{
  eventName: TelemetryEventName;
  attributes: Readonly<Record<string, unknown>>;
}>;

function recordingSinks() {
  const diagnostics: RecordedDiagnostic[] = [];
  const telemetry: RecordedTelemetry[] = [];
  return {
    diagnostics,
    telemetry,
    projector: createHttpObservationProjector({
      diagnostics: {
        record(input: DiagnosticRecordInput) {
          diagnostics.push(input);
        },
      },
      telemetry: {
        emit(
          eventName: TelemetryEventName,
          attributes: Record<string, unknown>,
        ) {
          telemetry.push(Object.freeze({ eventName, attributes }));
        },
      },
    }),
  };
}

describe("V3 HTTP observability projection", () => {
  it("projects every V3 terminal outcome through the closed diagnostics allowlist", async () => {
    const sinks = recordingSinks();

    const cases: readonly Readonly<{
      label: string;
      fetcher: typeof fetch;
    }>[] = [
      {
        label: "SUCCESS",
        fetcher: (async () =>
          Response.json([{ id: "a", name: "A" }])) as unknown as typeof fetch,
      },
      {
        label: "PROBLEM",
        fetcher: (async () =>
          Response.json(
            { type: "about:blank", title: "nope", status: 400 },
            { status: 400 },
          )) as unknown as typeof fetch,
      },
      {
        label: "TRANSPORT_FAILURE",
        fetcher: (async () => {
          throw new TypeError("network down");
        }) as unknown as typeof fetch,
      },
      {
        label: "CONTRACT_VIOLATION",
        fetcher: (async () =>
          new Response("<html/>", {
            status: 200,
            headers: { "content-type": "text/html" },
          })) as unknown as typeof fetch,
      },
    ];

    for (const testCase of cases) {
      const executor = createContractHttpExecutor({
        baseUrl: "https://api.example/",
        maxRetryAttempts: 0,
        attachCredentials: () => ({
          kind: "READY" as const,
          headers: {},
          credentials: "omit" as const,
        }),
        fetcher: testCase.fetcher,
        observe: sinks.projector,
      });
      await executor.execute(
        TEST_LIST_HTTP_CONTRACT,
        { limit: 5 },
        { routeId: ROUTE_ID, scope: scopeSnapshot() },
      );
    }

    expect(sinks.diagnostics).toHaveLength(cases.length);
    for (const recorded of sinks.diagnostics) {
      expect(recorded.eventId).toBe("http.request.completed");
      const contextKeys = Object.keys(recorded.context ?? {});
      expect(contextKeys).toEqual(
        expect.arrayContaining([
          "route_id",
          "operation_id",
          "operation",
          "outcome",
          "error_kind",
          "http_status_group",
          "attempt_count_bucket",
          "duration_bucket",
        ]),
      );
      for (const key of contextKeys) {
        expect(DIAGNOSTIC_CONTEXT_ALLOWLIST).toContain(key);
      }
      expect(contextKeys).not.toContain("attempts");
      expect(contextKeys).not.toContain("certainty");
      const projection = projectDiagnosticRecord(recorded);
      expect(projection.success).toBe(true);
    }
  });

  it("emits one failure telemetry event for a non-abort terminal failure", async () => {
    const sinks = recordingSinks();
    const executor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 0,
      attachCredentials: () => ({
        kind: "READY" as const,
        headers: {},
        credentials: "omit" as const,
      }),
      fetcher: (async () => {
        throw new TypeError("network down");
      }) as unknown as typeof fetch,
      observe: sinks.projector,
    });

    const outcome = await executor.execute(
      TEST_LIST_HTTP_CONTRACT,
      { limit: 5 },
      { routeId: ROUTE_ID, scope: scopeSnapshot() },
    );

    expect(outcome.kind).toBe("TRANSPORT_FAILURE");
    expect(sinks.telemetry).toHaveLength(1);
    const emitted = sinks.telemetry[0];
    expect(emitted?.eventName).toBe("api.request.failed");
    expect(emitted?.attributes).toMatchObject({
      route_id: ROUTE_ID,
      operation_id: "TEST_LIST_ENTITIES",
      error_kind: "NETWORK_FAILURE",
      http_status_group: "none",
      attempt_count_bucket: "1",
    });
    const projected = projectTelemetryEvent(
      emitted?.eventName ?? "api.request.failed",
      emitted?.attributes ?? {},
    );
    expect(projected.success).toBe(true);
    expect(sinks.diagnostics).toHaveLength(1);
  });

  it("does not emit failure telemetry for caller cancellation or scope fencing", async () => {
    const cancelled = recordingSinks();
    const callerController = new AbortController();
    callerController.abort();
    const cancelledExecutor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 0,
      attachCredentials: () => ({
        kind: "READY" as const,
        headers: {},
        credentials: "omit" as const,
      }),
      fetcher: (async () =>
        Response.json([{ id: "a", name: "A" }])) as unknown as typeof fetch,
      observe: cancelled.projector,
    });
    const cancelledOutcome = await cancelledExecutor.execute(
      TEST_LIST_HTTP_CONTRACT,
      { limit: 5 },
      {
        routeId: ROUTE_ID,
        scope: scopeSnapshot(),
        signal: callerController.signal,
      },
    );
    expect(cancelledOutcome.kind).toBe("CANCELLED");
    expect(cancelled.diagnostics).toHaveLength(1);
    expect(cancelled.telemetry).toHaveLength(0);

    const fenced = recordingSinks();
    const fencedExecutor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 0,
      attachCredentials: () => ({
        kind: "READY" as const,
        headers: {},
        credentials: "omit" as const,
      }),
      fetcher: (async () =>
        Response.json([{ id: "a", name: "A" }])) as unknown as typeof fetch,
      observe: fenced.projector,
    });
    const fencedOutcome = await fencedExecutor.execute(
      TEST_LIST_HTTP_CONTRACT,
      { limit: 5 },
      { routeId: ROUTE_ID, scope: scopeSnapshot(() => false) },
    );
    expect(fencedOutcome.kind).toBe("CONTRACT_VIOLATION");
    expect(fenced.diagnostics).toHaveLength(1);
    expect(fenced.telemetry).toHaveLength(0);
  });

  it("preserves the feature route id through the installed operation executor", async () => {
    const seen: Array<Readonly<Record<string, unknown>>> = [];
    const installed = createReferenceFeatureInstalledInput({
      contractOperations: Object.freeze({
        async execute(
          _operationId: string,
          _input: unknown,
          context?: Readonly<Record<string, unknown>>,
        ) {
          seen.push(Object.freeze({ ...(context ?? {}) }));
          return Object.freeze({
            kind: "SUCCESS" as const,
            value: [],
            metadata: Object.freeze({ status: 200 }),
            effect: "NOT_APPLICABLE" as const,
          });
        },
      }),
    });

    await installed.input.listResources({ limit: 20 });
    await installed.input.getResource("resource-1");

    expect(seen.map((context) => context.routeId)).toEqual([
      "REFERENCE_RESOURCE_LIST",
      "REFERENCE_RESOURCE_DETAIL",
    ]);
  });

  it("cannot change the HTTP result when diagnostics or telemetry throws", async () => {
    const projector = createHttpObservationProjector({
      diagnostics: {
        record() {
          throw new Error("diagnostics sink exploded");
        },
      },
      telemetry: {
        emit() {
          throw new Error("telemetry sink exploded");
        },
      },
    });
    const observe = vi.fn((observation: HttpExecutionObservation) => {
      projector(observation);
    });
    const executor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 0,
      attachCredentials: () => ({
        kind: "READY" as const,
        headers: {},
        credentials: "omit" as const,
      }),
      fetcher: (async () =>
        Response.json({ id: "created", name: "Created" }, {
          status: 201,
        })) as unknown as typeof fetch,
      observe,
    });

    const outcome = await executor.execute(
      TEST_CREATE_HTTP_CONTRACT,
      { name: "Created" },
      {
        routeId: ROUTE_ID,
        scope: scopeSnapshot(),
        intent: Object.freeze({
          intentId: "intent-1",
          operationId: "TEST_CREATE_ENTITY",
          canonicalInputIdentity: "opaque-input-identity",
          idempotencyKey: "key-1",
          createdAtMonotonicMs: 1,
        }),
      },
    );

    expect(outcome.kind).toBe("SUCCESS");
    expect(observe).toHaveBeenCalledTimes(1);
  });
});