import { measureShrinkWrapWidth } from "../list-table-v2/measureText";
import { formatCircularReference, isCircularReferenceMarker, normalizeVueValue } from "./normalizeValue";

type PlainObject = Record<string, unknown>;

type InlineContainerKind = "object" | "array" | "map" | "set";

export const JSON_VIEW_DEFAULT_FONT =
  "13px ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, Liberation Mono, monospace";

const FULLY_COLLAPSED_STRING = '"..."';
const FULLY_COLLAPSED_ARRAY = "[...]";
const FULLY_COLLAPSED_OBJECT = "{...}";
const MIN_KEPT_STRING_WIDTH = 150;

export interface InlinePreviewOptions {
  maxWidth: number;
  showDoubleQuotes: boolean;
  showKeyValueSpace: boolean;
}

export interface InlinePreviewResult {
  text: string;
  isComplete: boolean;
}

function measureWidth(text: string) {
  return measureShrinkWrapWidth(text, JSON_VIEW_DEFAULT_FONT);
}

function fits(text: string, maxWidth: number) {
  return measureWidth(text) <= maxWidth;
}

function isRecordLike(value: unknown): value is Record<string, unknown> {
  return value !== null && typeof value === "object" && !Array.isArray(value) && !(value instanceof Map) && !(value instanceof Set);
}

function getContainerKind(value: unknown): InlineContainerKind | null {
  if (Array.isArray(value)) {
    return "array";
  }
  if (value instanceof Map) {
    return "map";
  }
  if (value instanceof Set) {
    return "set";
  }
  if (isRecordLike(value)) {
    return "object";
  }
  return null;
}

function getCollapsedContainerText(kind: InlineContainerKind) {
  switch (kind) {
    case "map":
      return "Map {...}";
    case "set":
      return "Set [...]";
    case "object":
      return FULLY_COLLAPSED_OBJECT;
    case "array":
    default:
      return FULLY_COLLAPSED_ARRAY;
  }
}

function formatPrimitiveText(value: unknown) {
  const normalizedValue = normalizeVueValue(value);
  if (isCircularReferenceMarker(normalizedValue)) {
    return formatCircularReference(normalizedValue.path);
  }

  value = normalizedValue;

  if (typeof value === "string") {
    return JSON.stringify(value);
  }
  if (typeof value === "number" || typeof value === "boolean") {
    return String(value);
  }
  if (typeof value === "bigint") {
    return `${String(value)}n`;
  }
  if (value === null) {
    return "null";
  }
  if (value === undefined) {
    return "undefined";
  }
  if (typeof value === "symbol") {
    return value.toString();
  }
  if (typeof value === "function") {
    return value.name ? `[Function ${value.name}]` : "[Function]";
  }
  return String(value);
}

function formatObjectKey(key: string, showDoubleQuotes: boolean) {
  return showDoubleQuotes ? JSON.stringify(key) : key;
}

function buildTruncatedString(value: string, charCount: number) {
  if (charCount <= 0) {
    return FULLY_COLLAPSED_STRING;
  }

  const truncated = JSON.stringify(value.slice(0, charCount));
  return `${truncated.slice(0, -1)}..."`;
}

function formatStringPreview(value: string, options: InlinePreviewOptions): InlinePreviewResult {
  const full = JSON.stringify(value);
  if (fits(full, options.maxWidth)) {
    return { text: full, isComplete: true };
  }

  const preserveVisibleChars = measureWidth(full) <= MIN_KEPT_STRING_WIDTH;
  let low = preserveVisibleChars ? 1 : 0;
  let high = value.length;
  let bestCount = -1;

  while (low <= high) {
    const mid = Math.floor((low + high) / 2);
    const candidate = buildTruncatedString(value, mid);

    if (fits(candidate, options.maxWidth)) {
      bestCount = mid;
      low = mid + 1;
    } else {
      high = mid - 1;
    }
  }

  if (bestCount >= 0) {
    return {
      text: buildTruncatedString(value, bestCount),
      isComplete: false,
    };
  }

  return {
    text: FULLY_COLLAPSED_STRING,
    isComplete: false,
  };
}

function formatArrayPreview(
  value: unknown[],
  options: InlinePreviewOptions,
  ancestors: WeakMap<object, true>
): InlinePreviewResult {
  if (value.length === 0) {
    return { text: "[]", isComplete: true };
  }

  const parts: string[] = [];
  let isComplete = true;

  for (let index = 0; index < value.length; index++) {
    const prefix = parts.length > 0 ? `[${parts.join(", ")}, ` : "[";
    const tail = index < value.length - 1 ? ", ...]" : "]";
    const budget = options.maxWidth - measureWidth(prefix) - measureWidth(tail);

    if (budget <= 0) {
      return {
        text: parts.length > 0 ? `[${parts.join(", ")}, ...]` : FULLY_COLLAPSED_ARRAY,
        isComplete: false,
      };
    }

    const item = buildInlinePreview(value[index], { ...options, maxWidth: budget }, ancestors);
    const candidate = `${prefix}${item.text}${tail}`;

    if (!fits(candidate, options.maxWidth)) {
      return {
        text: parts.length > 0 ? `[${parts.join(", ")}, ...]` : FULLY_COLLAPSED_ARRAY,
        isComplete: false,
      };
    }

    parts.push(item.text);
    if (!item.isComplete) {
      isComplete = false;
    }
  }

  return {
    text: `[${parts.join(", ")}]`,
    isComplete,
  };
}

function formatObjectPreview(
  value: PlainObject,
  options: InlinePreviewOptions,
  ancestors: WeakMap<object, true>
): InlinePreviewResult {
  const entries = Object.entries(value);
  if (entries.length === 0) {
    return { text: "{}", isComplete: true };
  }

  const parts: string[] = [];
  let isComplete = true;

  for (let index = 0; index < entries.length; index++) {
    const [key, entryValue] = entries[index];
    const keyText = formatObjectKey(key, options.showDoubleQuotes);
    const pairPrefix = `${keyText}${options.showKeyValueSpace ? ": " : ":"}`;
    const prefix = parts.length > 0 ? `{${parts.join(", ")}, ${pairPrefix}` : `{${pairPrefix}`;
    const tail = index < entries.length - 1 ? ", ...}" : "}";
    const budget = options.maxWidth - measureWidth(prefix) - measureWidth(tail);

    if (budget <= 0) {
      return {
        text: parts.length > 0 ? `{${parts.join(", ")}, ...}` : FULLY_COLLAPSED_OBJECT,
        isComplete: false,
      };
    }

    const item = buildInlinePreview(entryValue, { ...options, maxWidth: budget }, ancestors);
    const candidate = `${prefix}${item.text}${tail}`;

    if (!fits(candidate, options.maxWidth)) {
      return {
        text: parts.length > 0 ? `{${parts.join(", ")}, ...}` : FULLY_COLLAPSED_OBJECT,
        isComplete: false,
      };
    }

    parts.push(`${pairPrefix}${item.text}`);
    if (!item.isComplete) {
      isComplete = false;
    }
  }

  return {
    text: `{${parts.join(", ")}}`,
    isComplete,
  };
}

export function buildInlinePreview(
  value: unknown,
  options: InlinePreviewOptions,
  ancestors = new WeakMap<object, true>()
): InlinePreviewResult {
  const normalizedValue = normalizeVueValue(value);
  if (isCircularReferenceMarker(normalizedValue)) {
    return {
      text: formatCircularReference(normalizedValue.path),
      isComplete: true,
    };
  }

  value = normalizedValue;

  if (typeof value === "string") {
    return formatStringPreview(value, options);
  }

  const kind = getContainerKind(value);
  if (!kind) {
    return {
      text: formatPrimitiveText(value),
      isComplete: true,
    };
  }

  if (kind === "map" || kind === "set") {
    return {
      text: getCollapsedContainerText(kind),
      isComplete: false,
    };
  }

  const reference = value as object;
  if (ancestors.has(reference)) {
    return {
      text: formatCircularReference(),
      isComplete: true,
    };
  }

  ancestors.set(reference, true);

  try {
    if (kind === "array") {
      return formatArrayPreview(value as unknown[], options, ancestors);
    }

    return formatObjectPreview(value as PlainObject, options, ancestors);
  } finally {
    ancestors.delete(reference);
  }
}