/**
 * @file Tests for hook-payload trimming (`server/lib/event-payload.js`): what is
 * dropped and kept, that every event insert goes through `trim_event_data`, that
 * the duplicate guard still matches a trimmed payload, and the one-time sweep.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const { describe, it } = require("node:test");
const assert = require("node:assert/strict");
const path = require("path");
const os = require("os");

const TMP = path.join(os.tmpdir(), `event-payload-${Date.now()}-${process.pid}`);
process.env.DASHBOARD_DB_PATH = path.join(TMP, "dashboard.db");
process.env.CLAUDE_HOME = path.join(TMP, "home");
process.env.DASHBOARD_DATA_DIR = path.join(TMP, "data");

const {
  trimHookPayload,
  trimEventData,
  sweepEventPayloads,
  STR_CAP,
} = require("../lib/event-payload");
const { db, stmts } = require("../db");

const big = (n, ch = "x") => ch.repeat(n);

describe("trimHookPayload", () => {
  it("drops an Edit's whole-file mirror and keeps the patch", () => {
    const patch = [{ oldStart: 1, lines: ["-a", "+b"] }];
    const out = trimHookPayload({
      tool_name: "Edit",
      tool_input: { file_path: "/a.js", old_string: "a", new_string: "b" },
      tool_response: {
        originalFile: big(50),
        oldString: "a",
        newString: "b",
        structuredPatch: patch,
      },
    });
    assert.equal(out.tool_response.originalFile, undefined);
    assert.equal(out.tool_response.oldString, undefined);
    assert.deepEqual(out.tool_response.structuredPatch, patch);
    assert.equal(out.tool_input.old_string, "a");
    assert.deepEqual(out._trimmed.sort(), [
      "tool_response.newString",
      "tool_response.oldString",
      "tool_response.originalFile",
    ]);
  });

  it("drops a Read's file body but keeps its counts", () => {
    const out = trimHookPayload({
      tool_name: "Read",
      tool_response: {
        type: "text",
        file: { filePath: "/a", content: "hi", numLines: 1, totalLines: 9 },
      },
    });
    assert.deepEqual(out.tool_response.file, { filePath: "/a", numLines: 1, totalLines: 9 });
    assert.deepEqual(out._trimmed, ["tool_response.file.content"]);
  });

  it("keeps another tool's `content` (Grep matches), only capping it", () => {
    const out = trimHookPayload({ tool_name: "Grep", tool_response: { content: "a:1:x" } });
    assert.equal(out.tool_response.content, "a:1:x");
    assert.equal(out._trimmed, undefined);
  });

  it("caps long strings to head + tail, idempotently, and leaves other fields", () => {
    const stdout = `HEAD${big(STR_CAP * 3)}TAIL`;
    const data = {
      tool_name: "Bash",
      prompt_id: "p",
      tool_response: { stdout, stderr: "", interrupted: false },
      tool_input: { command: "ls" },
    };
    const once = trimHookPayload(data);
    assert.ok(once.tool_response.stdout.length <= STR_CAP);
    assert.ok(once.tool_response.stdout.startsWith("HEAD"));
    assert.ok(once.tool_response.stdout.endsWith("TAIL"));
    assert.equal(once.tool_response.interrupted, false);
    assert.equal(once.prompt_id, "p");
    assert.deepEqual(trimHookPayload(once), once);
    assert.equal(data.tool_response.stdout, stdout, "input not mutated");
  });

  it("caps a string-typed tool_response", () => {
    const out = trimHookPayload({ tool_name: "Read", tool_response: big(STR_CAP * 2) });
    assert.ok(out.tool_response.length <= STR_CAP);
  });
});

describe("trimEventData", () => {
  it("passes short, null and non-JSON input through", () => {
    assert.equal(trimEventData(null), null);
    assert.equal(trimEventData('{"a":1}'), '{"a":1}');
    const junk = big(STR_CAP + 10, "{");
    assert.equal(trimEventData(junk), junk);
  });

  it("returns a long payload it has nothing to trim byte for byte (no number rounding)", () => {
    // 12345678901234567890 does not survive a JSON.parse/stringify round trip.
    const json = `{"tool_name":"Bash","id":12345678901234567890,"tool_input":{"a":"${big(
      STR_CAP - 10
    )}","b":"${big(STR_CAP - 10)}"}}`;
    assert.equal(trimEventData(json), json);
  });
});

describe("event inserts", () => {
  const payload = JSON.stringify({
    session_id: "s-trim",
    tool_name: "Edit",
    tool_response: { originalFile: big(STR_CAP * 4) },
  });

  it("store the trimmed payload and the duplicate guard still matches it", () => {
    db.prepare("INSERT OR IGNORE INTO sessions (id) VALUES ('s-trim')").run();
    stmts.insertEvent.run("s-trim", null, "PostToolUse", "Edit", "x", payload);
    const row = db.prepare("SELECT data FROM events WHERE session_id = 's-trim'").get();
    assert.ok(row.data.length < 500);
    assert.ok(stmts.findRecentDuplicateEvent.get("s-trim", "PostToolUse", payload));
  });

  it("the sweep trims rows stored untrimmed", async () => {
    db.prepare(
      "INSERT INTO events (session_id, event_type, data, created_at) VALUES ('s-trim', 'PostToolUse', ?, '2026-01-01T00:00:00Z')"
    ).run(payload);
    const r = await sweepEventPayloads(db, { chunk: 1 });
    assert.equal(r.rows, 1);
    assert.ok(r.bytesSaved > STR_CAP * 3);
    const again = await sweepEventPayloads(db);
    assert.equal(again.rows, 0);
  });

  it("the sweep commits once a chunk's bytes pass the budget, and still trims every row", async () => {
    db.prepare("INSERT OR IGNORE INTO sessions (id) VALUES ('s-sweep')").run();
    const ins = db.prepare(
      "INSERT INTO events (session_id, event_type, data, created_at) VALUES ('s-sweep', 'PostToolUse', ?, '2026-01-01T00:00:00Z')"
    );
    for (let i = 0; i < 5; i++) ins.run(payload);
    let txns = 0;
    const counting = {
      prepare: (sql) => db.prepare(sql),
      transaction: (fn) => {
        const t = db.transaction(fn);
        return (...a) => (txns++, t(...a));
      },
    };
    // Each payload is ~32 KB; a 1-byte budget closes the transaction after every row.
    const r = await sweepEventPayloads(counting, { chunk: 200, maxBytes: 1 });
    assert.equal(r.rows, 5);
    assert.ok(txns >= 5, `expected a transaction per row, got ${txns}`);
  });
});