import { describe, expect, it } from "vitest";
import {
  buildFastForwardRequest,
  fastForwardSeed,
  resolveFastForward,
} from "./fastForward.js";
import type { Project, SpawnPreset } from "./types.js";

const presets: SpawnPreset[] = [
  { id: "custom", label: "Custom…", command: "" },
  { id: "claude", label: "Claude", command: "claude" },
];

function project(overrides: Partial<Project>): Project {
  return {
    path: "/repos/p",
    name: "p",
    last_activity: new Date().toISOString(),
    ...overrides,
  };
}

describe("resolveFastForward (#67)", () => {
  it("resolves every default from the most recent project", () => {
    const projects = [
      project({ path: "/repos/old", name: "old", last_activity: "2020-01-01T00:00:00Z" }),
      project({
        path: "/repos/fresh",
        name: "fresh",
        base_repo: "/repos/fresh",
        last_command: "aider",
      }),
    ];
    const res = resolveFastForward(projects, presets, "amber-falcon");
    expect(res.project?.path).toBe("/repos/fresh");
    expect(res.command).toBe("aider");
    expect(res.handle).toBe("amber-falcon");

    const req = buildFastForwardRequest(res)!;
    expect(req.cwd).toBe("/repos/fresh");
    expect(req.command).toBe("aider");
    // No name (#131): the daemon names the session after its first prompt,
    // and a name here would collide with the branch handle.
    expect(req.metadata).toBeUndefined();
    expect(req.worktree).toEqual({
      base_repo: "/repos/fresh",
      branch: "amber-falcon",
      create_branch: true,
    });
  });

  it("prefers the focused session's project over the freshest one", () => {
    const projects = [
      project({ path: "/repos/fresh", name: "fresh", last_command: "claude" }),
      project({
        path: "/repos/current",
        name: "current",
        last_activity: "2020-01-01T00:00:00Z",
        last_command: "zsh",
      }),
    ];
    const res = resolveFastForward(projects, presets, "n", "/repos/current");
    expect(res.project?.path).toBe("/repos/current");
    expect(res.command).toBe("zsh");
  });

  it("falls back to the freshest project when the focused cwd is unknown", () => {
    const projects = [
      project({ path: "/repos/old", name: "old", last_activity: "2020-01-01T00:00:00Z" }),
      project({ path: "/repos/fresh", name: "fresh" }),
    ];
    const res = resolveFastForward(projects, presets, "n", "/repos/gone");
    expect(res.project?.path).toBe("/repos/fresh");
  });

  it("falls back to the first non-custom preset when there is no last command", () => {
    const res = resolveFastForward([project({ last_command: undefined })], presets, "n");
    expect(res.command).toBe("claude");
  });

  it("treats an empty last command as no command", () => {
    const res = resolveFastForward([project({ last_command: "" })], [presets[0]], "n");
    expect(res.command).toBeUndefined();
    expect(buildFastForwardRequest(res)).toBeNull();
  });

  it("resolves nothing when no projects are known yet", () => {
    const res = resolveFastForward([], presets, "n");
    expect(res.project).toBeUndefined();
    expect(buildFastForwardRequest(res)).toBeNull();
  });

  it("downgrades to a draft when the generated handle is missing", () => {
    const res = resolveFastForward([project({ last_command: "claude" })], presets);
    expect(res.handle).toBeUndefined();
    expect(buildFastForwardRequest(res)).toBeNull();
  });

  it("seeds the fallback draft with whatever did resolve", () => {
    const res = resolveFastForward(
      [project({ path: "/repos/p", base_repo: "/repos/p", last_command: "aider" })],
      presets,
    );
    expect(fastForwardSeed(res)).toEqual({
      cwd: "/repos/p",
      command: "aider",
      name: "",
      worktreeEnabled: true,
      worktreeBranch: undefined,
    });
  });

  it("seeds the handle as the branch and leaves the name field empty (#131)", () => {
    const res = resolveFastForward(
      [project({ path: "/repos/p", base_repo: "/repos/p", last_command: "aider" })],
      presets,
      "amber-falcon",
    );
    const seed = fastForwardSeed(res);
    expect(seed.name).toBe("");
    expect(seed.worktreeBranch).toBe("amber-falcon");
  });

  it("leaves the worktree default alone when not even a project resolved", () => {
    // Not `false`: the form defaults the toggle on and a false would stick,
    // so the fallback draft would disagree with a normally-opened draft and
    // with the TUI's fast path.
    const seed = fastForwardSeed(resolveFastForward([], presets));
    expect(seed.worktreeEnabled).toBeUndefined();
    expect(seed.cwd).toBe("");
  });
});