import {
  assert,
  assertEquals,
  assertMatch,
  assertRejects,
  assertStringIncludes,
} from "@std/assert";
import { BACKGROUND_CONTEXT as context } from "@earendil-works/chord/context";
import {
  type ImageContent,
  type Message,
  type ToolResultMessage,
  Type,
} from "@earendil-works/pi-ai";
import { createModels } from "@earendil-works/pi-ai/models";
import {
  fauxAssistantMessage,
  fauxProvider,
  fauxToolCall,
} from "@earendil-works/pi-ai/providers/faux";
import { MemoryStorage } from "@earendil-works/pi-durable";
import { defineExtension } from "@berry/api";
import { mkdir, writeFile } from "node:fs/promises";
import { join } from "node:path";
import { userInfo } from "node:os";
import code from "../extensions/code/mod.ts";
import { BerryError, Conversations, openBerry, Settings } from "./berry.ts";
import { dir, lastToolResult, sectionsSeen, setup, toolsOffered, turn } from "./fixture.ts";
import { TID_PATTERN } from "./tid.ts";
import { localOnly } from "./environment.ts";
import { tempDir } from "@berry/util";

Deno.test("configured and emitted state reaches the prompt, as an extension's section and as named ones", async () => {
  await using harness = await setup();
  const { berry, model } = harness;
  await assertRejects(
    () => berry.create({ extensions: { dir: { cwd: 5 } }, model }),
    BerryError,
    "dir: cwd:",
  );
  await assertRejects(
    () => berry.create({ extensions: { dir: { cwd: "here" } }, model }),
    BerryError,
    "dir: not absolute: here",
  );
  assertEquals(Object.keys(berry.configurationParameters("dir")?.properties ?? {}), ["cwd"]);
  assertEquals(berry.configurationParameters("gate"), null);

  const tid = await berry.create({ extensions: { dir: { cwd: "/seed" } }, model });
  assertMatch(tid, TID_PATTERN);
  const seen = await turn(harness, tid, [
    fauxAssistantMessage(fauxToolCall("cd", { path: "/next" }), { stopReason: "toolUse" }),
  ]);
  assertEquals(sectionsSeen(seen[0])[0].dir, "<dir>\ncwd: /seed\n</dir>");
  assertEquals(sectionsSeen(seen[1]).at(-1)?.dir, "<dir>\ncwd: /next\n</dir>");
  assertEquals(await berry.state(tid, "dir"), { cwd: "/next" });

  await berry.install(defineExtension({
    name: "sections",
    initial: () => ({ text: "first" }),
    apply: (_state, event: { text: string }) => event,
    setup(ext) {
      ext.prompt("extra", ({ state }) => state.text || undefined);
      return (conv) => conv.prompt(() => "stable");
    },
  }));
  const named = await berry.create({ extensions: { sections: {} }, model });
  const [initial] = await turn(harness, named, []);
  const shown = sectionsSeen(initial)[0];
  assertEquals(shown.sections, "<sections>\nstable\n</sections>");
  assertEquals(shown["sections_extra"], "<sections_extra>\nfirst\n</sections_extra>");
  for (const text of ["second", ""]) {
    await (await berry.emit(named, "sections", { text })).wait(context);
    const [seen] = await turn(harness, named, []);
    assertEquals(sectionsSeen(seen).at(-1), {
      "sections_extra": text ? `<sections_extra>\n${text}\n</sections_extra>` : null,
    });
  }
});

Deno.test("global prompt edits reach existing conversations and code prose follows the code extension", async () => {
  await using harness = await setup();
  const { berry, model } = harness;
  await berry.install(code);
  const coding = await berry.create({ extensions: { code: {} }, model });
  const plain = await berry.create({ extensions: {}, model });
  await turn(harness, coding, []);
  await turn(harness, plain, []);

  await berry.setSystemPrompt({
    userName: "Alex",
    generalGuidelines: "Ask $USER before deleting anything.",
    promptProse: { code: "Keep $USER's APIs small." },
  });
  const [changed] = await turn(harness, coding, []);
  const patch = sectionsSeen(changed).at(-1)!;
  assertStringIncludes(patch.lede!, "(Alex)");
  assertStringIncludes(patch.guidelines!, "Ask Alex before deleting anything.");
  assertStringIncludes(patch.code!, "Keep Alex's APIs small.");
  assertStringIncludes(patch.code!, "current working directory:");
  assert(!Object.hasOwn(patch, "code_guidelines"));
  assert(!Object.hasOwn(patch, "code_project") || patch["code_project"] === null);

  const [withoutCode] = await turn(harness, plain, []);
  const plainSections = Object.assign({}, ...sectionsSeen(withoutCode));
  assertStringIncludes(plainSections.guidelines!, "Ask Alex before deleting anything.");
  assert(!plainSections.code);

  await berry.setSystemPrompt({ generalGuidelines: "", promptProse: { code: "" } });
  const [cleared] = await turn(harness, coding, []);
  const removed = sectionsSeen(cleared).at(-1)!;
  assertEquals(removed.guidelines, null);
  // blank prose leaves the dynamic part of the section behind
  assertStringIncludes(removed.code!, "current working directory:");
  assert(!removed.code!.includes("Keep"));
  assert(!Object.hasOwn(removed, "lede"));
});

Deno.test("startup fills missing prompt settings without replacing saved fields or other settings", async () => {
  await using directory = await tempDir();
  const path = join(directory.path, "settings.sqlite");
  const { openNodeSqliteStorage } = await import("@earendil-works/pi-durable/storage/sqlite/node");
  const models = createModels();
  const berry = await openBerry(await openNodeSqliteStorage(path), models);
  assertEquals(
    (await berry.harness.snapshot(Settings, context))?.systemPrompt?.userName,
    userInfo().username,
  );
  await berry.harness.commit(async (tx) => {
    const settings = await tx.doc(Settings);
    settings.models = [{ provider: "offline", modelId: "kept" }];
    settings.environments = { remote: { ssh: "host" } };
    settings.systemPrompt = { userName: "Sam", generalGuidelines: "" } as NonNullable<
      typeof settings.systemPrompt
    >;
  }, context);
  await berry.close();
  const reopened = await openBerry(await openNodeSqliteStorage(path), models);
  try {
    const settings = (await reopened.harness.snapshot(Settings, context))!;
    assertEquals(settings.systemPrompt?.userName, "Sam");
    assertEquals(settings.systemPrompt?.generalGuidelines, "");
    assertEquals(settings.systemPrompt?.promptProse ?? {}, {});
    assertEquals(settings.models, [{ provider: "offline", modelId: "kept" }]);
    assertEquals(settings.environments, { remote: { ssh: "host" } });
  } finally {
    await reopened.close();
  }
});

Deno.test("AGENTS.md edits update the project section without repeating code guidelines", async () => {
  await using rootDir = await tempDir();
  const root = rootDir.path;
  await using harness = await setup();
  const { berry, model } = harness;
  await mkdir(join(root, "inner"));
  await writeFile(join(root, "AGENTS.md"), "outer rules");
  await writeFile(join(root, "inner", "AGENTS.md"), "inner rules");
  await berry.install(code);
  const tid = await berry.create({ extensions: { environment: { cwd: root }, code: {} }, model });
  const [initial] = await turn(harness, tid, []);
  const shown = sectionsSeen(initial)[0];
  assertStringIncludes(shown.code!, `current working directory: ${root}`);
  assertStringIncludes(shown.code!, "guidelines:");
  assert(!shown.code!.includes("outer rules"));
  assertStringIncludes(shown["code_project"]!, "outer rules");
  assert(!shown["code_project"]!.includes("current working directory:"));

  await writeFile(join(root, "AGENTS.md"), "revised rules");
  const [edited] = await turn(harness, tid, []);
  const patch = sectionsSeen(edited).at(-1)!;
  assertEquals(Object.keys(patch), ["code_project"]);
  assertStringIncludes(patch["code_project"]!, "revised rules");

  await berry.command(tid, "cd", "inner");
  const [moved] = await turn(harness, tid, []);
  const changed = sectionsSeen(moved).at(-1)!;
  assertStringIncludes(changed.code!, `current working directory: ${join(root, "inner")}`);
  assertStringIncludes(changed["code_project"]!, "inner rules");
});

Deno.test("direct tools are offered beside codemode, and the model reads their text or their images", async () => {
  const image: ImageContent = { type: "image", data: "bytes", mimeType: "image/png" };
  const values = ["plain text", { ...image, id: "capture" }, { type: "image", data: "bytes" }];
  await using harness = await setup();
  const { berry, model } = harness;
  await berry.install(defineExtension({
    name: "results",
    initial: () => null,
    setup(ext) {
      ext.tool({
        name: "result",
        description: "Return a value",
        parameters: Type.Object({ index: Type.Integer() }),
        expose: "model",
        execute: ({ index }) => values[index],
      });
    },
  }));
  const tid = await berry.create({ extensions: { dir: {}, results: {} }, model });
  const call = (name: string, args = {}) =>
    fauxAssistantMessage(fauxToolCall(name, args), { stopReason: "toolUse" });
  const seen = await turn(harness, tid, [
    call("shout"),
    ...values.map((_, index) => call("result", { index })),
  ]);
  assertEquals(toolsOffered(seen[0]).sort(), ["cd", "codemode", "result", "shout"]);
  assertEquals(lastToolResult(seen[1]).text, "HEY!");
  const expected: ToolResultMessage["content"][] = [
    [{ type: "text", text: "plain text" }],
    [image],
    [{ type: "text", text: JSON.stringify(values[2], null, 2) }],
  ];
  for (const [index, content] of expected.entries()) {
    const result = seen[index + 2].findLast((message) => message.role === "toolResult");
    assert(result?.role === "toolResult");
    assertEquals(result.content, content);
  }
});

Deno.test("an extension installs whole or not at all, and a new reducer re-derives state from history", async () => {
  await using harness = await setup();
  const { berry, model } = harness;
  for (const name of ["berry", "environment", "subagent"]) {
    await assertRejects(
      () => berry.install(defineExtension({ name, initial: () => null, setup() {} })),
      BerryError,
    );
  }
  let disposed = false;
  const shadow = (expose: "model" | "codemode") =>
    defineExtension({
      name: "shadow",
      initial: () => null,
      setup(ext) {
        ext.tool({
          name: "codemode",
          description: "",
          parameters: Type.Object({}),
          expose,
          execute: () => "",
        });
        ext.onDispose(() => void (disposed = true));
      },
    });
  await assertRejects(() => berry.install(shadow("model")), BerryError);
  assert(disposed, "a refused extension is disposed");
  assertEquals(berry.extensions().map((extension) => extension.name), ["dir", "gate"]);
  // scripts may have a tool by that name; it cannot reach the model
  await berry.install(shadow("codemode"));

  const tid = await berry.create({ extensions: { dir: { cwd: "/a" } }, model });
  await (await berry.emit(tid, "dir", { type: "cd", cwd: "b" })).wait(context);
  await assertRejects(() =>
    berry.install(defineExtension({
      name: "dir",
      initial: () => ({}),
      setup() {
        throw new Error("broken");
      },
    }))
  );
  assertEquals(await berry.state(tid, "dir"), { cwd: "b" });
  // v2 resolves relative paths against the current cwd
  await berry.install(
    dir((s, e) => ({ cwd: e.cwd.startsWith("/") ? e.cwd : `${s.cwd}/${e.cwd}` })),
  );
  assertEquals(await berry.state(tid, "dir"), { cwd: "/a/b" });
});

Deno.test("a conversation has its chosen extensions, the always-on ones, and the harness's own, under any name they have had", async () => {
  await using harness = await setup();
  const { berry, model } = harness;
  const names = async (id: string) =>
    (await (await berry.conversation(id))!.agent(context)).extensions.map((e) => e.name);
  // naming the harness's own changes nothing: every conversation has it
  const tid = await berry.create({ extensions: { berry: {}, dir: { cwd: "/a" } }, model });
  assertEquals(await names(tid), ["berry", "environment", "dir"]);
  await berry.install(defineExtension({
    name: "always",
    alwaysOn: true,
    initial: () => null,
    setup() {
      return (conv) => {
        conv.command({ name: "ping", description: "always there", execute: () => "pong" });
      };
    },
  }));
  assertEquals(await names(tid), ["berry", "environment", "always", "dir"]);
  const named = await berry.create({ extensions: { always: {}, dir: {} }, model });
  assertEquals(await names(named), ["berry", "environment", "always", "dir"]);
  assertEquals((await berry.commands(tid)).map(({ name }) => name), ["cd", "ping", "go"]);
  assertEquals(await berry.command(tid, "ping", ""), "pong");
  await berry.configure(named, { extensions: [] });
  assertEquals(await names(named), ["berry", "environment", "always"]);

  const conversation = (await berry.conversation(tid))!;
  const [, seed] =
    (await conversation.entries({ order: "ascending" }, 10, undefined, context)).items;
  await (await berry.emit(tid, "dir", { type: "cd", cwd: "/b" })).wait(context);
  berry.uninstall("dir");
  await berry.install({ ...dir(), name: "place", formerly: ["dir"] });
  assertEquals(await names(tid), ["berry", "environment", "always", "place"]);
  assertEquals(await berry.state(tid, "place"), { cwd: "/b" });
  // a fork from before the rename, and a conversation asked for by the old name
  const fork = await conversation.fork(seed.id, { ownership: { kind: "ownerless" } }, context);
  const forkTid = await berry.tidOf(fork.id);
  assertEquals(await names(forkTid), ["berry", "environment", "always", "place"]);
  assertEquals(await berry.state(forkTid, "place"), { cwd: "/a" });
  const asked = await berry.create({ extensions: { dir: { cwd: "/c" } }, model });
  assertEquals(await berry.state(asked, "place"), { cwd: "/c" });
});

Deno.test("a replaced load closes its channels and is disposed once the calls it started end", async () => {
  const { faux, berry, model } = await setup();
  const held = { entered: Promise.withResolvers<void>(), release: Promise.withResolvers<string>() };
  const opened: number[] = [];
  let disposed = 0;
  const version = (mark: number) =>
    defineExtension({
      name: "slow",
      alwaysOn: true,
      initial: () => null,
      setup(ext) {
        ext.channel({
          name: "line",
          parameters: Type.Object({}),
          open: () => void opened.push(mark),
        });
        ext.tool({
          name: "hold",
          description: "wait",
          parameters: Type.Object({}),
          expose: "model",
          execute: () => {
            held.entered.resolve();
            return held.release.promise;
          },
        });
        ext.onDispose(() => void (disposed += mark));
      },
    });
  await berry.install(version(1));
  const tid = await berry.create({ extensions: {}, model });
  let closed = 0;
  const channel = { send() {}, messages: new ReadableStream(), close: () => void closed++ };
  await berry.channel(tid, "slow", "line", {}, channel, new AbortController().signal);
  faux.setResponses([
    fauxAssistantMessage(fauxToolCall("hold", {}), { stopReason: "toolUse" }),
    fauxAssistantMessage("done"),
  ]);
  const conversation = (await berry.conversation(tid))!;
  const submission = await conversation.submit({ type: "input", content: "go" }, context);
  await held.entered.promise;

  await berry.install(version(10));
  assertEquals(disposed, 0);
  held.release.resolve("released");
  await submission.wait(context);
  await conversation.waitForIdle(context);
  assertEquals({ opened, closed, disposed }, { opened: [1], closed: 1, disposed: 1 });
  await berry.close();
  assertEquals(disposed, 11);
});

Deno.test("handlers answer only in conversations that have their extension", async () => {
  await using harness = await setup();
  const { berry, model } = harness;
  await berry.install(defineExtension({
    name: "asked",
    initial: () => "folded",
    setup(ext) {
      ext.handle({
        name: "echo",
        parameters: Type.Object({ times: Type.Integer({ default: 1 }) }),
        execute: ({ times }, ctx) => ({ state: ctx.state, times, aborted: ctx.signal.aborted }),
      });
      ext.handle({
        name: "fail",
        parameters: Type.Object({}),
        execute: () => {
          throw new Error("no such thing");
        },
      });
    },
  }));
  const tid = await berry.create({ extensions: { asked: {} }, model });
  assertEquals(await berry.request(tid, "asked", "echo", undefined), {
    state: "folded",
    times: 1,
    aborted: false,
  });
  assertEquals(
    (await berry.request(tid, "asked", "echo", { times: 3 }) as { times: number }).times,
    3,
  );
  await assertRejects(
    () => berry.request(tid, "asked", "echo", { times: "3" }),
    BerryError,
    "times",
  );
  await assertRejects(() => berry.request(tid, "asked", "fail", {}), BerryError, "no such thing");
  await assertRejects(() => berry.request(tid, "asked", "nope", {}), BerryError, "no handler");
  const without = await berry.create({ extensions: {}, model });
  await assertRejects(
    () => berry.request(without, "asked", "echo", {}),
    BerryError,
    "not in this conversation",
  );
});

Deno.test("forks and branches start from the state at their entry, and a branch keeps the conversation's tid, agent, and name", async () => {
  await using harness = await setup();
  const { faux, berry, model, gate } = harness;
  const tid = await berry.create({ extensions: { dir: { cwd: "/a" } }, model });
  const conversation = (await berry.conversation(tid))!;
  const [start, seed] =
    (await conversation.entries({ order: "ascending" }, 10, undefined, context)).items;
  assertEquals([start.kind, seed.kind], ["berry.start", "berry.event"]);
  await (await berry.emit(tid, "dir", { type: "cd", cwd: "/b" })).wait(context);

  const fork = await conversation.fork(seed.id, { ownership: { kind: "ownerless" } }, context);
  const forkTid = await berry.tidOf(fork.id);
  assert(forkTid !== tid);
  assertEquals(await berry.state(forkTid, "dir"), { cwd: "/a" });
  assertEquals(await berry.state(tid, "dir"), { cwd: "/b" });

  await berry.configure(tid, { extensions: ["dir", "gate"] });
  faux.setResponses([
    fauxAssistantMessage(fauxToolCall("hold", {}), { stopReason: "toolUse" }),
    fauxAssistantMessage("done"),
  ]);
  const submission = await conversation.submit({ type: "input", content: "go" }, context);
  await gate.entered.promise;
  await assertRejects(() => berry.branch(tid, seed.id), BerryError, "busy");
  gate.release.resolve("released");
  await submission.wait(context);
  await conversation.waitForIdle(context);
  const tip = (await conversation.context(context)).entries.at(-1)!.id;
  await berry.markRead(tid, tip);
  await berry.rename(tid, "  a custom name  ");

  const feed = (await berry.watchState(tid, "dir"))!;
  const moved = Promise.withResolvers<unknown>();
  feed.start((value) => Promise.resolve(moved.resolve(value)));
  await berry.branch(tid, seed.id);
  const branch = (await berry.conversation(tid))!;
  assert(branch.id !== conversation.id);
  assertEquals(await berry.tidOf(branch.id), tid);
  const index = (await berry.harness.snapshot(Conversations, context))!;
  assertEquals(Object.keys(index).sort(), [tid, forkTid].sort());
  assertEquals([index[tid].title, index[tid].readThrough], ["a custom name", tip]);
  assertEquals(await berry.state(tid, "dir"), { cwd: "/a" });
  assertEquals(await moved.promise, { cwd: "/a" });
  assertEquals(
    (await branch.agent(context)).extensions.map((extension) => extension.name),
    ["berry", "environment", "dir", "gate"],
  );
  await feed.stop();

  await berry.branch(tid, tip);
  assertEquals((await berry.harness.snapshot(Conversations, context))![tid].title, "a custom name");
  await berry.rename(tid, "   ");
  assertEquals((await berry.harness.snapshot(Conversations, context))![tid].title, undefined);
  await assertRejects(() => berry.rename("missing", "name"), BerryError, "No conversation");
});

Deno.test("commands are listed per conversation and run as the user, landing at once while busy", async () => {
  await using harness = await setup();
  const { faux, berry, model, gate } = harness;
  const tid = await berry.create({ extensions: { dir: {}, gate: {} }, model });
  const conversation = (await berry.conversation(tid))!;
  assertEquals((await berry.commands(tid)).map(({ name }) => name), ["cd", "go"]);
  assertEquals(await berry.command(tid, "go", "/cmd"), "/cmd");
  await conversation.waitForIdle(context);
  assertEquals(await berry.state(tid, "dir"), { cwd: "/cmd" });
  await assertRejects(() => berry.command(tid, "go", "relative"), BerryError, "not absolute");
  await assertRejects(() => berry.command(tid, "nope", ""), BerryError, "No command /nope");
  const other = await berry.create({ extensions: {}, model });
  assertEquals((await berry.commands(other)).map(({ name }) => name), ["cd"]);

  let next: readonly Message[] = [];
  faux.setResponses([
    fauxAssistantMessage(fauxToolCall("hold", {}), { stopReason: "toolUse" }),
    (ctx) => (next = ctx.messages, fauxAssistantMessage("done")),
  ]);
  const submission = await conversation.submit({ type: "input", content: "go" }, context);
  await gate.entered.promise;
  assertEquals(await berry.command(tid, "go", "/mid"), "/mid");
  assertEquals(await berry.state(tid, "dir"), { cwd: "/mid" });
  gate.release.resolve("released");
  await submission.wait(context);
  await conversation.waitForIdle(context);
  assertEquals(await berry.state(tid, "dir"), { cwd: "/mid" });
  // and the model hears of it at the next request, not only on the next input
  assertEquals(sectionsSeen(next).at(-1)?.dir, "<dir>\ncwd: /mid\n</dir>");
});

Deno.test("conversations use only models enabled in settings, at a thinking level the model supports", async () => {
  await using harness = await setup(undefined, {
    models: [{ id: "thinker", reasoning: true }, { id: "plain", reasoning: false }],
  });
  const { berry, model } = harness;
  const plain = { provider: "faux", modelId: "plain" };
  await assertRejects(
    () => berry.create({ extensions: {}, model: plain }),
    BerryError,
    "not enabled",
  );
  const tid = await berry.create({ extensions: {}, model, thinkingLevel: "high" });
  await assertRejects(() => berry.configure(tid, { model: plain }), BerryError, "not enabled");
  await berry.enableModels([model, plain, model]);
  assertEquals((await berry.harness.snapshot(Settings, context))?.models, [model, plain]);

  const agent = async (id: string) => await (await berry.conversation(id))!.agent(context);
  assertEquals((await agent(tid)).thinkingLevel, "high");
  await berry.configure(tid, { model: plain });
  assertEquals([(await agent(tid)).model, (await agent(tid)).thinkingLevel], [plain, "off"]);
  await berry.configure(tid, { model, thinkingLevel: "max" });
  assertEquals((await agent(tid)).thinkingLevel, "high");
  const created = await berry.create({ extensions: {}, model: plain, thinkingLevel: "high" });
  assertEquals((await agent(created)).thinkingLevel, "off");
});

Deno.test("extension prose defaults, overrides, blanks, selection, and $USER", async () => {
  await using harness = await setup();
  const { berry, model } = harness;
  await berry.install(defineExtension({
    name: "notes",
    initial: () => null,
    setup(ext) {
      ext.promptProse({ default: "Greet $USER warmly." });
      return (conv) => conv.prompt(() => "dynamic content");
    },
  }));
  assertEquals(berry.promptProseDefault("notes"), "Greet $USER warmly.");
  assertEquals(berry.promptProseDefault("dir"), null);
  const withNotes = await berry.create({ extensions: { notes: {} }, model });
  const withoutNotes = await berry.create({ extensions: {}, model });
  const [first] = await turn(harness, withNotes, []);
  const shown = sectionsSeen(first)[0];
  assertStringIncludes(shown.notes!, "Greet");
  assert(!shown.notes!.includes("$USER"));
  assert(!shown.notes!.includes("guidelines:"));
  assertStringIncludes(shown.notes!, "dynamic content");
  const [absent] = await turn(harness, withoutNotes, []);
  assert(!Object.assign({}, ...sectionsSeen(absent)).notes);

  await berry.setSystemPrompt({ userName: "Sam", promptProse: { notes: "Bid $USER farewell." } });
  const [overrode] = await turn(harness, withNotes, []);
  assertStringIncludes(sectionsSeen(overrode).at(-1)!.notes!, "Bid Sam farewell.");
  assertStringIncludes(sectionsSeen(overrode).at(-1)!.notes!, "dynamic content");

  await berry.setSystemPrompt({ promptProse: { notes: "" } });
  const [blanked] = await turn(harness, withNotes, []);
  assertStringIncludes(sectionsSeen(blanked).at(-1)!.notes!, "dynamic content");
  assert(!sectionsSeen(blanked).at(-1)!.notes!.includes("Bid"));

  const stored = (await berry.harness.snapshot(Settings, context))?.systemPrompt;
  assertEquals(stored?.promptProse?.notes, "");
});

Deno.test("startup migrates legacy code prose, preserving blank values and newer overrides", async () => {
  const { openNodeSqliteStorage } = await import("@earendil-works/pi-durable/storage/sqlite/node");
  for (
    const { legacy, override, expected } of [
      {
        legacy: "Legacy for $USER.",
        override: undefined,
        expected: "guidelines:\nLegacy for $USER.",
      },
      { legacy: "", override: undefined, expected: "" },
      { legacy: "Stale legacy.", override: "", expected: "" },
    ]
  ) {
    await using directory = await tempDir();
    const path = join(directory.path, "settings.sqlite");
    const models = createModels();
    const seed = await openBerry(await openNodeSqliteStorage(path), models);
    try {
      await seed.harness.commit(async (tx) => {
        const settings = await tx.doc(Settings);
        const stored = {
          userName: "Sam",
          generalGuidelines: "",
          codingGuidelines: legacy,
          promptProse: {
            other: "untouched",
            ...(override === undefined ? {} : { code: override }),
          },
        };
        settings.systemPrompt = stored;
      }, context);
    } finally {
      await seed.close();
    }
    const berry = await openBerry(await openNodeSqliteStorage(path), models);
    try {
      const stored = (await berry.harness.snapshot(Settings, context))?.systemPrompt;
      assertEquals(stored?.promptProse, { code: expected, other: "untouched" });
      assertEquals(stored?.userName, "Sam");
      assertEquals(stored?.generalGuidelines, "");
    } finally {
      await berry.close();
    }
  }
});

Deno.test("prompt prose overrides survive a missing extension", async () => {
  await using harness = await setup();
  const { berry } = harness;
  await berry.install(defineExtension({
    name: "ephemeral",
    initial: () => null,
    setup(ext) {
      ext.promptProse({ default: "default prose" });
    },
  }));
  await berry.setSystemPrompt({ promptProse: { ephemeral: "kept override" } });
  berry.uninstall("ephemeral");
  assertEquals(berry.promptProseDefault("ephemeral"), null);
  assertEquals(
    (await berry.harness.snapshot(Settings, context))?.systemPrompt?.promptProse?.ephemeral,
    "kept override",
  );
  await berry.install(defineExtension({
    name: "ephemeral",
    initial: () => null,
    setup(ext) {
      ext.promptProse({ default: "default prose" });
    },
  }));
  assertEquals(berry.promptProseDefault("ephemeral"), "default prose");
  assertEquals(
    (await berry.harness.snapshot(Settings, context))?.systemPrompt?.promptProse?.ephemeral,
    "kept override",
  );
});

Deno.test("a host lends /reload its extensions, and the prompt a guide to berry's source", async () => {
  const faux = fauxProvider();
  const models = createModels();
  models.setProvider(faux.provider);
  const model = { provider: "faux", modelId: faux.getModel().id };
  const reloaded: string[] = [];
  const loaded = (name: string) =>
    ({ name, description: null, status: "loaded", error: null }) as const;
  const failed = { ...loaded("two"), status: "failed", error: "no mod.ts" } as const;
  const berry = await openBerry(new MemoryStorage(), models, {
    root: "/somewhere/berry",
    check: () => Promise.resolve(null),
    restart: () => {},
    extensions: () => [loaded("one"), failed],
    reload: (name) => {
      reloaded.push(name);
      return Promise.resolve(name === "two" ? failed : loaded(name));
    },
  }, {
    async open(name, cwd, during) {
      return Object.assign(await localOnly.open("local", cwd, during), { name });
    },
    close: () => Promise.resolve(),
  });
  try {
    await berry.enableModels([model]);
    const tid = await berry.create({ extensions: {}, model });
    const seen = await turn({ faux, berry }, tid, []);
    assertStringIncludes(sectionsSeen(seen[0])[0].berry ?? "", "/somewhere/berry");
    assertEquals(toolsOffered(seen[0]), ["codemode"]);

    assertEquals(await berry.command(tid, "reload", " one "), "reloaded one");
    await assertRejects(() => berry.command(tid, "reload", ""), BerryError, "two: no mod.ts");
    assertEquals(reloaded, ["one", "one", "two"]);

    await berry.configureExtension(tid, "environment", { environment: "remote" });
    const [remote] = await turn({ faux, berry }, tid, []);
    assertEquals(sectionsSeen(remote).at(-1)?.berry, null);
    const fresh = await berry.create({
      extensions: { environment: { environment: "remote" } },
      model,
    });
    const [firstRemote] = await turn({ faux, berry }, fresh, []);
    assertEquals(sectionsSeen(firstRemote).at(-1)?.berry, undefined);

    await berry.configureExtension(tid, "environment", { environment: "local" });
    const [local] = await turn({ faux, berry }, tid, []);
    assertStringIncludes(sectionsSeen(local).at(-1)?.berry ?? "", "/somewhere/berry");
  } finally {
    await berry.close();
  }
});