const assert = require("assert");
const fs = require("fs");
const path = require("path");
const vm = require("vm");

const rootDir = path.resolve(__dirname, "..", "..");

const loadRelayForwardingModule = (injected = {}) => {
    const filePath = path.join(
        rootDir,
        "pages/api/middleware/relayForwarding.js"
    );
    let source = fs.readFileSync(filePath, "utf8");

    source = source.replace(/import[\s\S]*?from\s+"[^"]+";\n?/g, "");
    source = source.replace(/export const\s+/g, "const ");

    source +=
        "\nmodule.exports = { relayGet, relayGetData, forwardGetData };\n";

    const context = {
        module: { exports: {} },
        exports: {},
        require,
        process,
        setTimeout,
        clearTimeout,
        console: {
            log: () => {},
            info: () => {},
            warn: () => {},
            error: () => {}
        },
        ...injected
    };

    vm.runInNewContext(source, context, { filename: filePath });
    return context.module.exports;
};

const tests = [];
const test = (name, fn) => tests.push({ name, fn });

test("forwardGetData retries retryable HTTP status and then succeeds", async () => {
    let callCount = 0;
    const infoLogs = [];

    const mod = loadRelayForwardingModule({
        axios: {
            get: async () => {
                callCount += 1;
                if (callCount === 1) {
                    const error = new Error("temporary outage");
                    error.response = { status: 503 };
                    throw error;
                }

                return { data: { ok: true } };
            }
        },
        getToken: async () => ({ access_token: "token" }),
        hashAPIPath: () => "&hash=abc",
        azureHeaders: () => ({ headers: { Authorization: "Bearer token" } }),
        redactSensitive: (value) => value,
        consoleLogger: () => {},
        console: {
            log: () => {},
            info: (...args) => infoLogs.push(args),
            warn: () => {},
            error: () => {}
        }
    });

    const result = await mod.forwardGetData({
        queryUrl: "incidents?$top=1",
        maxRetries: 1,
        retryBaseDelayMs: 0,
        retryMaxDelayMs: 0
    });

    assert.strictEqual(callCount, 2);
    assert.deepStrictEqual(result.data, { ok: true });
    assert.strictEqual(result.accessToken, "token");

    const eventNames = infoLogs.map((entry) => entry[0]);
    assert.ok(eventNames.includes("relay_request_started"));
    assert.ok(eventNames.includes("relay_request_retrying"));
    assert.ok(eventNames.includes("relay_request_succeeded"));

    const retryEvent = infoLogs.find(
        (entry) => entry[0] === "relay_request_retrying"
    );
    assert.ok(retryEvent);

    const retryPayload = retryEvent[1];
    assert.strictEqual(retryPayload.statusClass, "5xx");
    assert.strictEqual(retryPayload.attemptsMade, 1);
    assert.strictEqual(retryPayload.retryCountUsed, 0);
    assert.strictEqual(retryPayload.remainingRetries, 1);
    assert.ok(typeof retryPayload.relayRequestId === "string");

    const successEvent = infoLogs.find(
        (entry) => entry[0] === "relay_request_succeeded"
    );
    assert.ok(successEvent);

    const successPayload = successEvent[1];
    assert.strictEqual(successPayload.statusClass, "none");
    assert.strictEqual(successPayload.attemptsMade, 2);
    assert.strictEqual(successPayload.retryCountUsed, 1);
    assert.ok(typeof successPayload.elapsedMs === "number");
});

test("forwardGetData does not retry non-retryable HTTP status", async () => {
    let callCount = 0;
    const infoLogs = [];

    const mod = loadRelayForwardingModule({
        axios: {
            get: async () => {
                callCount += 1;
                const error = new Error("bad request");
                error.response = { status: 400 };
                throw error;
            }
        },
        getToken: async () => ({ access_token: "token" }),
        hashAPIPath: () => "&hash=abc",
        azureHeaders: () => ({ headers: {} }),
        redactSensitive: (value) => value,
        consoleLogger: () => {},
        console: {
            log: () => {},
            info: (...args) => infoLogs.push(args),
            warn: () => {},
            error: () => {}
        }
    });

    let thrown = null;
    try {
        await mod.forwardGetData({
            queryUrl: "incidents?$top=1",
            maxRetries: 3,
            retryBaseDelayMs: 0,
            retryMaxDelayMs: 0
        });
    } catch (error) {
        thrown = error;
    }

    assert.ok(thrown);
    assert.strictEqual(callCount, 1);

    const failedEvent = infoLogs.find(
        (entry) => entry[0] === "relay_request_failed"
    );
    assert.ok(failedEvent);

    const failedPayload = failedEvent[1];
    assert.strictEqual(failedPayload.statusClass, "4xx");
    assert.strictEqual(failedPayload.attemptsMade, 1);
    assert.strictEqual(failedPayload.retryCountUsed, 0);
    assert.ok(typeof failedPayload.elapsedMs === "number");
});

test("forwardGetData does not retry unauthorized status", async () => {
    let callCount = 0;

    const mod = loadRelayForwardingModule({
        axios: {
            get: async () => {
                callCount += 1;
                const error = new Error("unauthorized");
                error.response = { status: 401 };
                throw error;
            }
        },
        getToken: async () => ({ access_token: "token" }),
        hashAPIPath: () => "&hash=abc",
        azureHeaders: () => ({ headers: {} }),
        redactSensitive: (value) => value,
        consoleLogger: () => {}
    });

    let thrown = null;
    try {
        await mod.forwardGetData({
            queryUrl: "incidents?$top=1",
            maxRetries: 3,
            retryBaseDelayMs: 0,
            retryMaxDelayMs: 0
        });
    } catch (error) {
        thrown = error;
    }

    assert.ok(thrown);
    assert.strictEqual(callCount, 1);
});

test("relayGet avoids duplicate consoleLogger when relay layer already logged", async () => {
    let consoleLoggerCalls = 0;
    let respondErrorCalls = 0;

    const mod = loadRelayForwardingModule({
        axios: {
            get: async () => {
                const error = new Error("bad request");
                error.response = { status: 400 };
                throw error;
            }
        },
        getToken: async () => ({ access_token: "token" }),
        hashAPIPath: () => "&hash=abc",
        azureHeaders: () => ({ headers: {} }),
        redactSensitive: (value) => value,
        consoleLogger: () => {
            consoleLoggerCalls += 1;
        },
        respondSuccess: () => {},
        respondError: () => {
            respondErrorCalls += 1;
        }
    });

    await mod.relayGet({
        queryUrl: "incidents?$top=1",
        res: {},
        errorResponse: { code: "FAILED" }
    });

    assert.strictEqual(consoleLoggerCalls, 0);
    assert.strictEqual(respondErrorCalls, 1);
});

test("forwardGetData clamps invalid env config values to safe bounds", async () => {
    const previousEnv = {
        RELAY_TIMEOUT_MS: process.env.RELAY_TIMEOUT_MS,
        RELAY_RETRY_MAX: process.env.RELAY_RETRY_MAX,
        RELAY_RETRY_BASE_DELAY_MS: process.env.RELAY_RETRY_BASE_DELAY_MS,
        RELAY_RETRY_MAX_DELAY_MS: process.env.RELAY_RETRY_MAX_DELAY_MS
    };

    process.env.RELAY_TIMEOUT_MS = "999999";
    process.env.RELAY_RETRY_MAX = "999";
    process.env.RELAY_RETRY_BASE_DELAY_MS = "-1";
    process.env.RELAY_RETRY_MAX_DELAY_MS = "999999";

    let capturedOptions = null;

    const mod = loadRelayForwardingModule({
        axios: {
            get: async (url, options) => {
                capturedOptions = options;
                return { data: { ok: true } };
            }
        },
        getToken: async () => ({ access_token: "token" }),
        hashAPIPath: () => "&hash=abc",
        azureHeaders: () => ({ headers: {} }),
        redactSensitive: (value) => value,
        consoleLogger: () => {}
    });

    await mod.forwardGetData({
        queryUrl: "incidents?$top=1"
    });

    assert.strictEqual(capturedOptions.timeout, 30000);

    process.env.RELAY_TIMEOUT_MS = previousEnv.RELAY_TIMEOUT_MS;
    process.env.RELAY_RETRY_MAX = previousEnv.RELAY_RETRY_MAX;
    process.env.RELAY_RETRY_BASE_DELAY_MS =
        previousEnv.RELAY_RETRY_BASE_DELAY_MS;
    process.env.RELAY_RETRY_MAX_DELAY_MS = previousEnv.RELAY_RETRY_MAX_DELAY_MS;
});

test("forwardGetData applies timeout and appendHash=false behavior", async () => {
    let capturedUrl = null;
    let capturedOptions = null;

    const mod = loadRelayForwardingModule({
        axios: {
            get: async (url, options) => {
                capturedUrl = url;
                capturedOptions = options;
                return { data: { ok: true } };
            }
        },
        getToken: async () => ({ access_token: "token" }),
        hashAPIPath: () => "&hash=abc",
        azureHeaders: () => ({ headers: { Accept: "application/json" } }),
        redactSensitive: (value) => value,
        consoleLogger: () => {}
    });

    await mod.forwardGetData({
        baseUrl: "http://localhost:3000",
        queryUrl: "/api/endpoint/example",
        appendHash: false,
        timeoutMs: 1234,
        maxRetries: 0
    });

    assert.strictEqual(
        capturedUrl,
        "http://localhost:3000/api/endpoint/example"
    );
    assert.strictEqual(capturedOptions.timeout, 1234);
    assert.strictEqual(capturedOptions.headers.Accept, "application/json");
});

test("forwardGetData telemetry request id is stable across lifecycle events", async () => {
    const infoLogs = [];
    let callCount = 0;

    const mod = loadRelayForwardingModule({
        axios: {
            get: async () => {
                callCount += 1;
                if (callCount === 1) {
                    const error = new Error("service unavailable");
                    error.response = { status: 503 };
                    throw error;
                }

                return { data: { ok: true }, status: 200 };
            }
        },
        getToken: async () => ({ access_token: "token" }),
        hashAPIPath: () => "&hash=abc",
        azureHeaders: () => ({ headers: {} }),
        redactSensitive: (value) => value,
        consoleLogger: () => {},
        console: {
            log: () => {},
            info: (...args) => infoLogs.push(args),
            warn: () => {},
            error: () => {}
        }
    });

    await mod.forwardGetData({
        queryUrl: "incidents?$top=1",
        maxRetries: 1,
        retryBaseDelayMs: 0,
        retryMaxDelayMs: 0
    });

    const lifecycleEvents = infoLogs
        .filter((entry) =>
            [
                "relay_request_started",
                "relay_request_retrying",
                "relay_request_succeeded"
            ].includes(entry[0])
        )
        .map((entry) => entry[1]);

    assert.strictEqual(lifecycleEvents.length, 3);

    const relayRequestIds = lifecycleEvents.map(
        (event) => event.relayRequestId
    );
    assert.ok(
        relayRequestIds.every((id) => typeof id === "string" && id.length > 0)
    );
    assert.strictEqual(new Set(relayRequestIds).size, 1);
});

test("forwardGetData relayPolicy override controls retry behavior", async () => {
    let callCount = 0;
    const infoLogs = [];

    const mod = loadRelayForwardingModule({
        axios: {
            get: async () => {
                callCount += 1;
                if (callCount < 3) {
                    const error = new Error("temporary outage");
                    error.response = { status: 503 };
                    throw error;
                }

                return { data: { ok: true }, status: 200 };
            }
        },
        getToken: async () => ({ access_token: "token" }),
        hashAPIPath: () => "&hash=abc",
        azureHeaders: () => ({ headers: {} }),
        redactSensitive: (value) => value,
        consoleLogger: () => {},
        console: {
            log: () => {},
            info: (...args) => infoLogs.push(args),
            warn: () => {},
            error: () => {}
        }
    });

    const result = await mod.forwardGetData({
        queryUrl: "incidents?$top=1",
        maxRetries: 0,
        relayPolicy: {
            maxRetries: 2,
            retryBaseDelayMs: 0,
            retryMaxDelayMs: 0,
            method: "GET"
        }
    });

    assert.strictEqual(callCount, 3);
    assert.deepStrictEqual(result.data, { ok: true });

    const startEvent = infoLogs.find(
        (entry) => entry[0] === "relay_request_started"
    );
    assert.ok(startEvent);
    assert.strictEqual(startEvent[1].maxRetries, 2);
    assert.strictEqual(startEvent[1].method, "GET");
});

test("forwardGetData blocks retries for non-idempotent methods by default", async () => {
    let callCount = 0;
    const infoLogs = [];

    const mod = loadRelayForwardingModule({
        axios: {
            get: async () => {
                callCount += 1;
                const error = new Error("temporary outage");
                error.response = { status: 503 };
                throw error;
            }
        },
        getToken: async () => ({ access_token: "token" }),
        hashAPIPath: () => "&hash=abc",
        azureHeaders: () => ({ headers: {} }),
        redactSensitive: (value) => value,
        consoleLogger: () => {},
        console: {
            log: () => {},
            info: (...args) => infoLogs.push(args),
            warn: () => {},
            error: () => {}
        }
    });

    let thrown = null;
    try {
        await mod.forwardGetData({
            queryUrl: "incidents?$top=1",
            relayPolicy: {
                method: "POST",
                maxRetries: 3,
                retryBaseDelayMs: 0,
                retryMaxDelayMs: 0
            }
        });
    } catch (error) {
        thrown = error;
    }

    assert.ok(thrown);
    assert.strictEqual(callCount, 1);

    const retryEvents = infoLogs.filter(
        (entry) => entry[0] === "relay_request_retrying"
    );
    assert.strictEqual(retryEvents.length, 0);

    const failedEvent = infoLogs.find(
        (entry) => entry[0] === "relay_request_failed"
    );
    assert.ok(failedEvent);
    assert.strictEqual(failedEvent[1].method, "POST");
});

test("forwardGetData can allow retries for non-idempotent methods when explicitly enabled", async () => {
    let callCount = 0;

    const mod = loadRelayForwardingModule({
        axios: {
            get: async () => {
                callCount += 1;
                if (callCount === 1) {
                    const error = new Error("temporary outage");
                    error.response = { status: 503 };
                    throw error;
                }

                return { data: { ok: true }, status: 200 };
            }
        },
        getToken: async () => ({ access_token: "token" }),
        hashAPIPath: () => "&hash=abc",
        azureHeaders: () => ({ headers: {} }),
        redactSensitive: (value) => value,
        consoleLogger: () => {}
    });

    const result = await mod.forwardGetData({
        queryUrl: "incidents?$top=1",
        relayPolicy: {
            method: "PATCH",
            maxRetries: 1,
            retryBaseDelayMs: 0,
            retryMaxDelayMs: 0,
            allowNonIdempotentRetries: true
        }
    });

    assert.strictEqual(callCount, 2);
    assert.deepStrictEqual(result.data, { ok: true });
});

const run = async () => {
    let passed = 0;
    for (const currentTest of tests) {
        await currentTest.fn();
        passed += 1;
    }
    console.log(
        `Phase 21 relay-forwarding hardening tests passed (${passed}/${tests.length}).`
    );
};

module.exports = run;

if (require.main === module) {
    run().catch((error) => {
        console.error(error);
        process.exit(1);
    });
}