// Receive-chain micro-benchmark (RoadMap #5).
//
// Measured paths:
//   1. `parseMsgPush` — pure decode + decoder dispatch (no SQLite, no
//      event emit). The protobuf workload only.
//   2. `IncomingPacketPipeline.process` — full receive pipeline:
//      decode + decoder + handleSideEffects (identity-service SQLite
//      writes) + event emit through BridgeEventBus.
//
// Run via:  pnpm -F @snowluma/protocol bench
//
// Output is `tinybench` ops/sec — vitest's built-in `bench()` is just a
// thin wrapper. Run before AND after a perf commit; the delta is what
// matters (RoadMap #5 commit messages quote the % shift).

import fs from 'node:fs';
import os from 'node:os';
import path from 'node:path';
import { bench, describe } from 'vitest';
import { protobuf_encode } from '@snowluma/proton';
import type { PacketInfo } from '@snowluma/common/protocol-types';
import type { PushMsg } from '@snowluma/proto-defs/message';
import type { GroupChange } from '@snowluma/proto-defs/notify';
import { parseMsgPush, MSG_PUSH_CMD } from '../src/msg-push/index';
import { IdentityService } from '../src/identity-service';
import { BridgeEventBus } from '../src/event-bus';
import { GroupInviteTracker } from '../src/group-invite-tracker';
import { IncomingPacketPipeline } from '../src/packet-pipeline';

const SELF_UIN = '10001';
const GROUP_ID = 123456789;
const SENDER_UIN = 22222;
const SENDER_UID = 'u_sender';

// ─── Synthetic packet builders ───

function makeGroupTextPacket(): PacketInfo {
    const body = protobuf_encode<PushMsg>({
        message: {
            responseHead: { fromUin: SENDER_UIN, fromUid: SENDER_UID },
            contentHead: {
                msgType: 82,
                subType: 1,
                sequence: 1234,
                timestamp: 1710000000,
                msgId: 999999,
            },
            body: {
                richText: {
                    elems: [{ text: { str: 'hello world from bench' } }],
                },
            },
        },
        status: 0,
        grpInfo: { groupUin: GROUP_ID },
    } as any);
    return {
        pid: 1,
        uin: SELF_UIN,
        serviceCmd: MSG_PUSH_CMD,
        seqId: 1,
        retCode: 0,
        fromClient: false,
        body,
    };
}

function makeGroupMixedPacket(): PacketInfo {
    const body = protobuf_encode<PushMsg>({
        message: {
            responseHead: { fromUin: SENDER_UIN, fromUid: SENDER_UID },
            contentHead: {
                msgType: 82,
                subType: 1,
                sequence: 1235,
                timestamp: 1710000000,
                msgId: 999998,
            },
            body: {
                richText: {
                    elems: [
                        { text: { str: '@some_user ' } },
                        { face: { index: 76 } },
                        { text: { str: 'hello ' } },
                        { srcMsg: { origSeqs: [4242] } },
                        { text: { str: ' world' } },
                    ],
                },
            },
        },
        status: 0,
        grpInfo: { groupUin: GROUP_ID },
    } as any);
    return {
        pid: 1,
        uin: SELF_UIN,
        serviceCmd: MSG_PUSH_CMD,
        seqId: 2,
        retCode: 0,
        fromClient: false,
        body,
    };
}

function makeGroupJoinPacket(): PacketInfo {
    const content = protobuf_encode<GroupChange>({
        groupUin: GROUP_ID,
        memberUid: 'u_newcomer',
    });
    const body = protobuf_encode<PushMsg>({
        message: {
            responseHead: { fromUin: GROUP_ID },
            contentHead: { msgType: 33, timestamp: 1710000000 },
            body: { msgContent: content },
        },
        status: 0,
    } as any);
    return {
        pid: 1,
        uin: SELF_UIN,
        serviceCmd: MSG_PUSH_CMD,
        seqId: 3,
        retCode: 0,
        fromClient: false,
        body,
    };
}

// ─── Setup helpers ───

// In-memory identity (no SQLite writes) — used for the "pure decode"
// bench to isolate proton + decoder cost from DB cost.
function makeIdentity(): IdentityService {
    return IdentityService.memory(SELF_UIN);
}

// SQLite-backed identity in a temp file — used for the full-pipeline
// bench so we capture per-event identity writes. Temp dir is cleaned
// implicitly on process exit (OS tmp policy); we don't need to unlink
// because each `bench()` recreates it.
function makeIdentityWithDb(): IdentityService {
    const dir = fs.mkdtempSync(path.join(os.tmpdir(), 'snowluma-bench-recv-'));
    return new IdentityService(SELF_UIN, path.join(dir, 'identity.db'));
}

function makePipeline(identity: IdentityService): IncomingPacketPipeline {
    const events = new BridgeEventBus();
    events.on('group_message', () => {
        /* drain */
    });
    events.on('group_member_join', () => {
        /* drain */
    });
    const pipeline = new IncomingPacketPipeline({
        identity,
        events,
        fetchGroupList: async () => {},
        fetchGroupMemberList: async () => {},
        resolveGroupJoinRequest: async () => null,
        groupInvites: new GroupInviteTracker(),
    });
    pipeline.registerCmd(MSG_PUSH_CMD, parseMsgPush);
    return pipeline;
}

// ─── Benches ───

const groupText = makeGroupTextPacket();
const groupMixed = makeGroupMixedPacket();
const groupJoin = makeGroupJoinPacket();

describe('parseMsgPush — pure decode + dispatch (no SQLite, no emit)', () => {
    const identityPure = makeIdentity();
    bench('group_message (text only)', () => {
        parseMsgPush(groupText, identityPure);
    });
    bench('group_message (5 mixed elements)', () => {
        parseMsgPush(groupMixed, identityPure);
    });
    bench('group_member_join', () => {
        parseMsgPush(groupJoin, identityPure);
    });
});

describe('IncomingPacketPipeline.process — full pipeline (with SQLite identity writes)', () => {
    const pipelineText = makePipeline(makeIdentityWithDb());
    const pipelineMixed = makePipeline(makeIdentityWithDb());
    const pipelineJoin = makePipeline(makeIdentityWithDb());

    bench('group_message (text only)', () => {
        pipelineText.process(groupText);
    });
    bench('group_message (5 mixed elements)', () => {
        pipelineMixed.process(groupMixed);
    });
    bench('group_member_join', () => {
        pipelineJoin.process(groupJoin);
    });
});