import {
  isWindowScanDisplayLayer,
  WINDOW_SCAN_DISPLAY_LAYER_ORDER,
  WINDOW_SCAN_SCORING_LAYER_ORDER,
  type WindowScanLayer,
  type WindowScanTransition,
} from "./rectification-agentic/v9/refinement-packet";
import {
  workingRectificationHouseTable,
  type RectificationCandidateResult,
  type RectificationHouseTable,
} from "./rectification-candidate-result";

export const RECTIFICATION_BOARD_SPLIT_MIN_PX = 832;

export type GroupedWindowMinute = Readonly<{
  at: string;
  scoringLayers: readonly WindowScanLayer[];
  displayLayers: readonly WindowScanLayer[];
}>;

export type RectificationBoardDiff = Readonly<{
  houseNumbers: readonly number[];
  lagnaChanged: boolean;
  timeChanged: boolean;
  transitionMinutes: readonly string[];
  liveMessage: string;
}>;

const SCORING_RANK = new Map<WindowScanLayer, number>(
  WINDOW_SCAN_SCORING_LAYER_ORDER.map((layer, index) => [layer, index]),
);
const DISPLAY_RANK = new Map<WindowScanLayer, number>(
  WINDOW_SCAN_DISPLAY_LAYER_ORDER.map((layer, index) => [layer, index]),
);

const EMPTY_DIFF: RectificationBoardDiff = {
  houseNumbers: [],
  lagnaChanged: false,
  timeChanged: false,
  transitionMinutes: [],
  liveMessage: "",
};

function sortLayers(
  layers: readonly WindowScanLayer[],
  rank: ReadonlyMap<WindowScanLayer, number>,
): readonly WindowScanLayer[] {
  return [...layers].sort((left, right) => (rank.get(left) ?? 99) - (rank.get(right) ?? 99));
}

export function groupWindowTransitions(
  transitions: readonly WindowScanTransition[],
): readonly GroupedWindowMinute[] {
  const byMinute = new Map<string, { scoring: Set<WindowScanLayer>; display: Set<WindowScanLayer> }>();
  for (const item of transitions) {
    const bucket = byMinute.get(item.at) ?? { scoring: new Set<WindowScanLayer>(), display: new Set<WindowScanLayer>() };
    if (isWindowScanDisplayLayer(item.layer)) bucket.display.add(item.layer);
    else bucket.scoring.add(item.layer);
    byMinute.set(item.at, bucket);
  }
  return [...byMinute.entries()]
    .sort(([left], [right]) => left.localeCompare(right))
    .map(([at, bucket]) => ({
      at,
      scoringLayers: sortLayers([...bucket.scoring], SCORING_RANK),
      displayLayers: sortLayers([...bucket.display], DISPLAY_RANK),
    }));
}

export function changedHouseNumbers(
  previous: RectificationHouseTable | null,
  next: RectificationHouseTable | null,
): readonly number[] {
  if (!previous || !next) return [];
  const changed: number[] = [];
  for (let index = 0; index < 12; index += 1) {
    const before = previous.houses[index];
    const after = next.houses[index];
    if (!before || !after) continue;
    if (before.sign !== after.sign || before.occupants.join("\0") !== after.occupants.join("\0")) {
      changed.push(after.house);
    }
  }
  return changed;
}

function groupedMinuteKey(row: GroupedWindowMinute): string {
  return `${row.at}|${row.scoringLayers.join(",")}|${row.displayLayers.join(",")}`;
}

export function changedTransitionMinutes(
  previous: readonly WindowScanTransition[],
  next: readonly WindowScanTransition[],
): readonly string[] {
  const before = new Map(groupWindowTransitions(previous).map((row) => [row.at, groupedMinuteKey(row)]));
  const changed: string[] = [];
  for (const row of groupWindowTransitions(next)) {
    if (before.get(row.at) !== groupedMinuteKey(row)) changed.push(row.at);
  }
  return changed;
}

function joinHouses(houses: readonly number[]): string {
  return houses.map((house) => `第${house}宫`).join("、");
}

export function rectificationBoardLiveMessage(input: Readonly<{
  previous: RectificationCandidateResult | null;
  next: RectificationCandidateResult | null;
  houseNumbers: readonly number[];
  lagnaChanged: boolean;
  timeChanged: boolean;
  transitionMinutes: readonly string[];
}>): string {
  const nextTable = input.next ? workingRectificationHouseTable(input.next) : null;
  if (!nextTable) return "";
  if (!input.previous) {
    return `当前本命宫位已按 ${nextTable.time} 排出，上升${nextTable.lagna}。`;
  }
  const parts: string[] = [];
  if (input.timeChanged || input.lagnaChanged) {
    parts.push(`本命宫位已按 ${nextTable.time} 重算（上升 ${nextTable.lagna}）。`);
  }
  if (input.houseNumbers.length > 0 && !(input.timeChanged && input.houseNumbers.length === 12)) {
    parts.push(`${joinHouses(input.houseNumbers)}已更新。`);
  }
  if (input.transitionMinutes.length > 0) {
    parts.push("换升时刻已更新。");
  }
  return parts.join("");
}

export function diffRectificationBoard(
  previous: RectificationCandidateResult | null,
  next: RectificationCandidateResult | null,
): RectificationBoardDiff {
  if (!next) return EMPTY_DIFF;
  const previousTable = previous ? workingRectificationHouseTable(previous) : null;
  const nextTable = workingRectificationHouseTable(next);
  const houseNumbers = changedHouseNumbers(previousTable, nextTable);
  const lagnaChanged = Boolean(previousTable && nextTable && previousTable.lagna !== nextTable.lagna);
  const timeChanged = Boolean(previousTable && nextTable && previousTable.time !== nextTable.time);
  const transitionMinutes = previous
    ? changedTransitionMinutes(previous.windowTransitions, next.windowTransitions)
    : [];
  return {
    houseNumbers,
    lagnaChanged,
    timeChanged,
    transitionMinutes,
    liveMessage: rectificationBoardLiveMessage({
      previous,
      next,
      houseNumbers,
      lagnaChanged,
      timeChanged,
      transitionMinutes,
    }),
  };
}

export function rectificationBoardPeekCopy(result: RectificationCandidateResult | null): Readonly<{
  title: string;
  detail: string | null;
}> {
  const table = result ? workingRectificationHouseTable(result) : null;
  if (!table) {
    return { title: "当前盘面", detail: "补充经历后会在这里更新" };
  }
  return { title: "当前盘面", detail: `${table.time} · 上升${table.lagna}` };
}

export function workingRectificationTime(result: RectificationCandidateResult | null): string | null {
  if (!result) return null;
  return result.selectedTime ?? result.representativeTime ?? workingRectificationHouseTable(result)?.time ?? null;
}