import { describe, expect, it } from "vitest";
import {
  resolveTemplateValues,
  substituteSnapshot,
  substituteTemplateTokens,
  validateTemplateVars
} from "./template-vars.js";

describe("template variables (T-142)", () => {
  it("validates a well-formed variable list", () => {
    const r = validateTemplateVars([
      { name: "title", label: "Title", type: "text", required: true },
      { name: "count", label: "Count", type: "number", defaultValue: "0" },
      { name: "date", label: "Date", type: "date" },
      { name: "status", label: "Status", type: "select", options: ["open", "closed"] }
    ]);
    expect(r.ok).toBe(true);
    if (r.ok) expect(r.vars).toHaveLength(4);
  });

  it("rejects bad names, duplicates, unknown types, empty select options", () => {
    for (const bad of [
      [{ name: "bad name!", label: "L", type: "text" }],
      [{ name: "a", label: "L", type: "text" }, { name: "a", label: "M", type: "text" }],
      [{ name: "a", label: "L", type: "widget" }],
      [{ name: "a", label: "L", type: "select" }],
      "nope"
    ]) {
      const r = validateTemplateVars(bad);
      expect(r.ok).toBe(false);
      if (!r.ok) expect(r.errors.length).toBeGreaterThan(0);
    }
  });

  it("resolves values: defaults, required, coercion, select membership, length cap", () => {
    const r = validateTemplateVars([
      { name: "title", label: "Title", type: "text", required: true },
      { name: "count", label: "Count", type: "number", defaultValue: "3" },
      { name: "date", label: "Date", type: "date" },
      { name: "status", label: "Status", type: "select", options: ["open", "closed"] }
    ]);
    expect(r.ok).toBe(true);
    const vars = (r as { ok: true; vars: import("./template-vars.js").TemplateVar[] }).vars;

    // required missing → error
    expect(resolveTemplateValues(vars, {}).ok).toBe(false);
    // all good
    const good = resolveTemplateValues(vars, { title: "T", count: "5", date: "2026-10-11", status: "open" });
    expect(good.ok).toBe(true);
    if (good.ok) {
      expect(good.values.count).toBe("5");
      expect(good.values.status).toBe("open");
    }
    // default applied when omitted
    const def = resolveTemplateValues(vars, { title: "T" });
    expect(def.ok).toBe(true);
    if (def.ok) expect(def.values.count).toBe("3");
    // bad select value / bad date / non-number
    for (const v of [
      { title: "T", status: "maybe" },
      { title: "T", date: "tomorrow" },
      { title: "T", count: "abc" }
    ]) {
      expect(resolveTemplateValues(vars, v).ok).toBe(false);
    }
    // text length cap
    expect(resolveTemplateValues(vars, { title: "T", count: "x".repeat(2001) }).ok).toBe(false);
  });

  it("substitutes tokens (plain text; unknown tokens → empty)", () => {
    expect(substituteTemplateTokens("Hi {{name}}, due {{date}}", { name: "Ada", date: "2026-10-11" })).toBe(
      "Hi Ada, due 2026-10-11"
    );
    expect(substituteTemplateTokens("{{ missing }} stays", {})).toBe(" stays");
    expect(substituteTemplateTokens("no tokens", { a: "b" })).toBe("no tokens");
  });

  it("substitutes across the snapshot (page + blocks + children) without mutating input", () => {
    const snapshot = {
      page: { title: "{{title}} draft", icon: "📄", description: "owner: {{owner}}" },
      blocks: [
        { id: "b1", type: "PARAGRAPH", content: { text: "Count: {{count}}" }, properties: {}, parentId: null, position: "A" },
        { id: "b2", type: "TODO", content: { text: "ship" }, properties: {}, parentId: null, position: "B" }
      ],
      children: [{ title: "{{title}} child", blocks: [{ content: { text: "{{owner}} owns" } }] }]
    };
    const out = substituteSnapshot(snapshot, { title: "Q3", owner: "Ada", count: "7" });
    expect(out.page.title).toBe("Q3 draft");
    expect(out.page.description).toBe("owner: Ada");
    const firstBlock = out.blocks[0] as { content: { text: string } } | undefined;
    expect(firstBlock?.content.text).toBe("Count: 7");
    const firstChild = out.children[0];
    expect(firstChild?.title).toBe("Q3 child");
    const childBlock = firstChild?.blocks[0] as { content: { text: string } } | undefined;
    expect(childBlock?.content.text).toBe("Ada owns");
    // input untouched
    expect(snapshot.page.title).toBe("{{title}} draft");
  });
});