import { describe, expect, it } from "vitest";
import { readFileSync } from "node:fs";
import {
  insertAtGap,
  insertNextTo,
  keyVariantGroups,
  orderSegments,
  renumber,
  swapKeys,
} from "../src/domain/idxOrder";
import type { OrderContext } from "../src/domain/idxOrder";
import {
  assignLines,
  keyRect,
  matrixSequence,
  scanKeys,
  splitHalves,
  type ScanOptions,
} from "../src/domain/idxScan";
import { matchPlacements } from "../src/domain/idxImport";
import { readLayoutPlacements } from "../src/io/layoutImport";
import { importKle } from "../src/io/kleImport";
import { flattenKeys } from "../src/domain/geometry";
import type { KeyRect } from "../src/domain/rows";
import type { FlatKey, PhyFile } from "../src/domain/phy";

const sample = (path: string) =>
  JSON.parse(readFileSync(new URL(`../../samples/${path}`, import.meta.url), "utf8")) as unknown;
const gen = () => {
  let i = 0;
  return () => `${String(++i).padStart(8, "0")}-0000-4000-8000-000000000000`;
};

/** Context where `hidden` keys are in group g (with every `grouped` visible key) and the rest are common. */
const ctx = (visible: string[], grouped: string[] = []): OrderContext => ({
  visible: new Set(visible),
  groups: new Map(grouped.map((id) => [id, ["g"]])),
});

describe("IDX order editing", () => {
  it("keeps the ISO Enter next to the ANSI Enter when inserting after it", () => {
    // a = ANSI Enter (shown), h = ISO Enter (hidden), b = common key
    const c = ctx(["a", "b", "x"], ["a", "h"]);
    expect(orderSegments(["a", "h", "b"], c)).toEqual([["a", "h"], ["b"]]);
    expect(insertNextTo(["a", "h", "b", "x"], c, "x", "a", true)).toEqual(["a", "h", "x", "b"]);
    expect(insertNextTo(["a", "h", "b", "x"], c, "x", "b", false)).toEqual(["a", "h", "x", "b"]);
  });

  it("attaches hidden keys forward only to a key sharing their group", () => {
    const c = ctx(["p", "q"], ["h1", "h2", "q"]);
    expect(orderSegments(["p", "h1", "h2", "q"], c)).toEqual([["p"], ["h1", "h2", "q"]]);
    // shares with neither: stays with the key before
    expect(orderSegments(["p", "z", "q"], ctx(["p", "q"]))).toEqual([["p", "z"], ["q"]]);
    // shares with both: stays with the key before
    expect(orderSegments(["p", "h", "q"], ctx(["p", "q"], ["p", "h", "q"]))).toEqual([["p", "h"], ["q"]]);
    // once a hidden key goes forward, the rest of the run follows to keep the order
    const mixed = {
      visible: new Set(["p", "q"]),
      groups: new Map([
        ["h1", ["g"]],
        ["q", ["g"]],
        ["h2", ["k"]],
        ["p", ["k"]],
      ]),
    };
    expect(orderSegments(["p", "h1", "h2", "q"], mixed)).toEqual([["p"], ["h1", "h2", "q"]]);
    // leading hidden keys attach to the first visible key, trailing ones to the last
    expect(orderSegments(["z", "p", "q", "y"], ctx(["p", "q"]))).toEqual([
      ["z", "p"],
      ["q", "y"],
    ]);
    expect(orderSegments(["z"], ctx([]))).toEqual([]);
  });

  it("moves a key between two others like a list move", () => {
    const c = ctx(["k0", "k1", "k2", "k3", "k4", "k5"]);
    const order = ["k0", "k1", "k2", "k3", "k4", "k5"];
    // n = 4 dropped between i = 1 and i + 1 = 2: lands on 2, 2..3 shift back
    expect(insertNextTo(order, c, "k4", "k1", true)).toEqual(["k0", "k1", "k4", "k2", "k3", "k5"]);
    expect(insertNextTo(order, c, "k4", "k2", false)).toEqual(["k0", "k1", "k4", "k2", "k3", "k5"]);
    // n = 1 dropped between i = 3 and 4: lands on 3, 2..3 shift forward
    expect(insertNextTo(order, c, "k1", "k3", true)).toEqual(["k0", "k2", "k3", "k1", "k4", "k5"]);
    expect(insertNextTo(order, c, "k1", "k4", false)).toEqual(["k0", "k2", "k3", "k1", "k4", "k5"]);
    expect(insertNextTo(order, c, "k1", "k1", true)).toEqual(order);
    expect(insertAtGap(order, c, "k0", 99)).toEqual(["k1", "k2", "k3", "k4", "k5", "k0"]);
  });

  it("leaves hidden keys in place when their visible key moves away", () => {
    const c = ctx(["a", "b", "c"], ["a", "h"]);
    expect(insertNextTo(["a", "h", "b", "c"], c, "a", "c", true)).toEqual(["h", "b", "c", "a"]);
  });

  it("registers an unregistered key at the drop position", () => {
    const c = ctx(["a", "b", "new"]);
    expect(insertNextTo(["a", "b"], c, "new", "b", false)).toEqual(["a", "new", "b"]);
  });

  it("swaps only the two keys", () => {
    expect(swapKeys(["a", "h", "b", "c"], "a", "c")).toEqual(["c", "h", "b", "a"]);
    expect(() => swapKeys(["a"], "a", "zz")).toThrow();
  });

  it("renumbers a sequence from the position of its first key, moving attached hidden keys along", () => {
    const c = ctx(["a", "b", "c", "d"], ["b", "h"]);
    const order = ["a", "b", "h", "c", "d"];
    expect(renumber(order, c, ["d", "b"])).toEqual(["a", "c", "d", "b", "h"]);
    expect(renumber(order, c, ["b", "a"])).toEqual(["b", "h", "a", "c", "d"]);
    expect(renumber(order, c, ["c", "a"])).toEqual(["b", "h", "c", "a", "d"]);
    // unregistered keys are registered inside the block; an all-new sequence goes to the end
    expect(renumber(["a", "b"], ctx(["a", "b", "n"]), ["n", "b"])).toEqual(["a", "n", "b"]);
    expect(renumber(["a"], ctx(["a", "n"]), ["n"])).toEqual(["a", "n"]);
  });

  it("never duplicates or drops keys", () => {
    const c = ctx(["a", "b", "c", "d"], ["a", "h1", "c", "h2"]);
    const order = ["h1", "a", "b", "h2", "c", "d", "z"];
    const hiddenOf = (o: string[]) => o.filter((id) => !c.visible.has(id));
    const moved = renumber(order, c, ["d", "c", "b", "a"]);
    expect([...moved].sort()).toEqual([...order].sort());
    // hidden keys travel with their visible key here
    expect(moved).toEqual(["d", "z", "h2", "c", "b", "h1", "a"]);
    for (const r of [
      insertNextTo(order, c, "a", "d", true),
      insertNextTo(order, c, "d", "a", false),
      swapKeys(order, "b", "d"),
    ]) {
      expect([...r].sort()).toEqual([...order].sort());
      expect(hiddenOf(r)).toEqual(hiddenOf(order));
    }
  });

  it("lists VariantGroup ancestors including nested groups", () => {
    const { phy } = importKle(sample("kle/macropad-4x4.json"), { idGenerator: gen() });
    const [a, b] = phy.root as Extract<PhyFile["root"][number], { type: "key" }>[];
    const nested: PhyFile = {
      ...phy,
      root: [
        {
          type: "variantGroup",
          id: "outer",
          name: "o",
          default: "v1",
          transform: { x: 0, y: 0, rotation: 0 },
          children: [
            {
              type: "variant",
              id: "v1",
              name: "1",
              children: [
                {
                  type: "variantGroup",
                  id: "inner",
                  name: "i",
                  default: "v2",
                  transform: { x: 0, y: 0, rotation: 0 },
                  children: [{ type: "variant", id: "v2", name: "2", children: [a!] }],
                },
              ],
            },
          ],
        },
        b!,
      ],
    };
    const groups = keyVariantGroups(nested);
    expect(groups.get(a!.id)).toEqual(["outer", "inner"]);
    expect(groups.get(b!.id)).toEqual([]);
  });
});

const r = (id: string, x: number, y: number, w = 1, h = 1): KeyRect => ({ id, x, y, w, h });
const options = (o: Partial<ScanOptions>): ScanOptions => ({
  kind: "rows",
  direction: "normal",
  left: "normal",
  right: "normal",
  offsets: new Map(),
  ...o,
});

describe("IDX preset scans", () => {
  // Two 2x2 halves with a 2U gap
  const split = [r("l00", 0, 0), r("l01", 1, 0), r("l10", 0, 1), r("l11", 1, 1)].concat([
    r("r00", 4, 0),
    r("r01", 5, 0),
    r("r10", 4, 1),
    r("r11", 5, 1),
  ]);

  it("scans rows, columns, halves and alternating halves", () => {
    expect(scanKeys(split, options({})).sequence).toEqual([
      "l00",
      "l01",
      "r00",
      "r01",
      "l10",
      "l11",
      "r10",
      "r11",
    ]);
    expect(scanKeys(split, options({ direction: "reversed" })).sequence.slice(0, 4)).toEqual([
      "r01",
      "r00",
      "l01",
      "l00",
    ]);
    expect(scanKeys(split, options({ kind: "columns" })).sequence.slice(0, 4)).toEqual([
      "l00",
      "l10",
      "l01",
      "l11",
    ]);
    expect(scanKeys(split, options({ kind: "columns", direction: "reversed" })).sequence.slice(0, 2)).toEqual(
      ["r01", "r11"],
    );
    const halves = scanKeys(split, options({ kind: "halves", right: "reversed" }));
    expect(halves.sequence).toEqual(["l00", "l01", "l10", "l11", "r01", "r00", "r11", "r10"]);
    expect(halves.boundary).toBe(3);
    expect(scanKeys(split, options({ kind: "alternating" })).sequence).toEqual([
      "l00",
      "l01",
      "r00",
      "r01",
      "l10",
      "l11",
      "r10",
      "r11",
    ]);
  });

  it("splits a board without a gap at the middle of its x range", () => {
    const halves = splitHalves([r("a", 0, 0), r("b", 1, 0), r("c", 2, 0), r("d", 3, 0, 2)]);
    expect(halves.boundary).toBe(2.5);
    expect([...halves.left]).toEqual(["a", "b"]);
  });

  it("shifts the row assignment of one column", () => {
    // column-staggered: the outer column sits a full row lower and is detected one row off
    const keys = [r("o0", 0, 1), r("o1", 0, 2), r("a0", 1, 0), r("a1", 1, 1), r("a2", 1, 2)];
    const before = assignLines(keys, "row", new Map());
    expect(before.lines).toEqual([["a0"], ["o0", "a1"], ["o1", "a2"]]);
    const outer = before.crossLines.findIndex((col) => col.includes("o0"));
    const after = assignLines(keys, "row", new Map([[outer, -1]]));
    expect(after.lines).toEqual([["o0", "a0"], ["o1", "a1"], ["a2"]]);
  });

  it("uses the bounding box of rotated keys", () => {
    const rotated = keyRect({
      key: {
        type: "key",
        id: "k",
        profile: "p",
        transform: { x: 0, y: 0, rotation: 0 },
        size: { w: 2, h: 1 },
      },
      x: 0,
      y: 0,
      rotation: 90,
      path: [],
    });
    expect(rotated.x).toBeCloseTo(-1);
    expect(rotated.w).toBeCloseTo(1);
    expect(rotated.h).toBeCloseTo(2);
  });

  it("orders by matrix row then col and leaves unwired keys at the end", () => {
    const positions = new Map([
      ["a", { row: 1, col: 0 }],
      ["b", { row: 0, col: 2 }],
      ["c", { row: 0, col: 1 }],
    ]);
    expect(matrixSequence(["x", "a", "b", "y", "c"], positions)).toEqual(["c", "b", "a", "x", "y"]);
  });
});

describe("IDX import from existing definitions", () => {
  const shown = (phy: PhyFile): FlatKey[] => flattenKeys(phy).filter((k) => !k.key.decal);

  it("matches every key of the KLE the project came from, in KLE order", () => {
    for (const file of ["kle/macropad-4x4.json", "kle/cr0wn60.json"]) {
      const { phy, keyOrder } = importKle(sample(file), { idGenerator: gen() });
      const result = matchPlacements(readLayoutPlacements(sample(file)).placements, shown(phy));
      expect(result.unmatched, file).toBe(0);
      expect(result.ids).toEqual(keyOrder.filter((id) => shown(phy).some((k) => k.key.id === id)));
    }
  });

  it("matches the VIA definition of cr0wn60 against its KLE", () => {
    const { phy } = importKle(sample("kle/cr0wn60.json"), { idGenerator: gen() });
    const keys = shown(phy);
    const result = matchPlacements(readLayoutPlacements(sample("via/cr0wn60.json")).placements, keys);
    expect(result.ids.length).toBe(keys.length);
    expect(new Set(result.ids).size).toBe(result.ids.length);
  });

  it("reads QMK layouts, asks for a name when there are several, and applies rotation", () => {
    const kle = [
      [{ r: 30, rx: 2, ry: 1, x: 0.5 }, "A"],
      [{ x: -1 }, "B"],
    ];
    const { phy } = importKle(kle, { idGenerator: gen() });
    const keys = shown(phy);
    const qmk = {
      layouts: {
        LAYOUT_a: {
          layout: [
            { matrix: [0, 1], x: 1, y: 2, r: 30, rx: 2, ry: 1 },
            { matrix: [0, 0], x: 2.5, y: 1, r: 30, rx: 2, ry: 1 },
          ],
        },
        LAYOUT_b: { layout: [{ matrix: [0, 0], x: 0, y: 0 }] },
      },
    };
    expect(readLayoutPlacements(qmk)).toEqual({ placements: [], layouts: ["LAYOUT_a", "LAYOUT_b"] });
    const read = readLayoutPlacements(qmk, "LAYOUT_a");
    const result = matchPlacements(read.placements, keys);
    expect(result.unmatched).toBe(0);
    const label = (id: string) => keys.find((k) => k.key.id === id)!.key.labels?.find(Boolean);
    expect(result.ids.map(label)).toEqual(["B", "A"]);
    expect(matchPlacements(readLayoutPlacements(qmk, "LAYOUT_b").placements, keys).unmatched).toBe(1);
  });
});