/**
 * 清单上的一句话与检索 —— 输入摘要 / 输入文件 / 产出摘要 / 过滤 / 统计 / 分页,全是纯函数。
 */
import type { InstanceState, InstanceStats, InstanceSummary } from '@contracts';
import { INSTANCE_STATES } from '@contracts';
import type { FieldSpec } from './launch-params.ts';

export const SUMMARY_MAX = 80;

/** 压空白、截到一行能摆下的长度;截了才加省略号(加了等于说「后面还有」) */
export function clip(text: string, max = SUMMARY_MAX): string {
  const one = text.replace(/\s+/g, ' ').trim();
  return one.length > max ? `${one.slice(0, max - 1)}…` : one;
}

/**
 * 输入一句话:清单标了 `x-control: textarea` 的那格最像「这单是什么」(客户需求 / 本轮说明),
 * 没有就取最长的那个顶层字符串;都没有退回来件主题;再没有就空串。文件字段不算。
 */
export function inputSummaryOf(data: Readonly<Record<string, unknown>>, specs: readonly FieldSpec[], fallback?: string): string {
  const fileKeys = new Set(specs.filter((s) => s.format === 'file').map((s) => s.key));
  for (const spec of specs) {
    if (spec.control !== 'textarea') continue;
    const value = data[spec.key];
    if (typeof value === 'string' && value.trim() !== '') return clip(value);
  }
  let longest = '';
  for (const [key, value] of Object.entries(data)) {
    if (fileKeys.has(key) || typeof value !== 'string') continue;
    if (value.trim().length > longest.trim().length) longest = value;
  }
  if (longest.trim() !== '') return clip(longest);
  return fallback === undefined ? '' : clip(fallback);
}

export type InputFileRef = { readonly index: number; readonly name: string; readonly contentType: string; readonly size: number; readonly ref: string };

/** `format: 'file'` 的字段里那些 `{name, contentType, size, ref}`;`index` 跨字段连续编号 */
export function inputFilesOf(data: Readonly<Record<string, unknown>>, specs: readonly FieldSpec[]): InputFileRef[] {
  const out: InputFileRef[] = [];
  for (const spec of specs) {
    if (spec.format !== 'file') continue;
    const raw = data[spec.key];
    const list = Array.isArray(raw) ? raw : raw === undefined || raw === null ? [] : [raw];
    for (const one of list) {
      if (typeof one !== 'object' || one === null) continue;
      const file = one as Record<string, unknown>;
      const ref = file['ref'];
      if (typeof ref !== 'string' || ref === '') continue;
      const size = file['size'];
      out.push({
        index: out.length,
        name: typeof file['name'] === 'string' ? file['name'] : '未命名',
        contentType: typeof file['contentType'] === 'string' ? file['contentType'] : 'application/octet-stream',
        size: typeof size === 'number' && Number.isFinite(size) ? size : 0,
        ref,
      });
    }
  }
  return out;
}

/** 产出一句话:有存档文件摆文件名;没有就摆发了哪几口;都没有 = null(前端摆 `-`) */
export function outputSummaryOf(archivedNames: readonly string[], firedPorts: readonly string[]): string | null {
  if (archivedNames.length > 0) return clip(archivedNames.join('、'));
  if (firedPorts.length > 0) return clip(`已发口:${firedPorts.join('、')}`);
  return null;
}

export type InstanceQuery = {
  readonly id?: string | undefined;
  readonly ownerId?: string | undefined;
  readonly state?: InstanceState | undefined;
  readonly startedFrom?: string | undefined;
  readonly startedTo?: string | undefined;
};

function dayBound(day: string, end: boolean): number | undefined {
  const m = /^(\d{4})-(\d{2})-(\d{2})$/.exec(day);
  if (m === null) return undefined;
  const [y, mo, d] = [Number(m[1]), Number(m[2]), Number(m[3])];
  // 服务进程的本地时区:单时区部署;「含两端整日」
  return end ? new Date(y, mo - 1, d, 23, 59, 59, 999).getTime() : new Date(y, mo - 1, d, 0, 0, 0, 0).getTime();
}

/** 四条件 AND;`id` 模糊对实例号与任务 id 的子串(不分大小写) */
export function applyInstanceFilters(items: readonly InstanceSummary[], q: InstanceQuery): InstanceSummary[] {
  const needle = q.id?.trim().toLowerCase() ?? '';
  const from = q.startedFrom === undefined ? undefined : dayBound(q.startedFrom, false);
  const to = q.startedTo === undefined ? undefined : dayBound(q.startedTo, true);
  return items.filter((it) => {
    if (needle !== '' && !it.no.toLowerCase().includes(needle) && !it.id.toLowerCase().includes(needle)) return false;
    if (q.ownerId !== undefined && q.ownerId !== '' && it.owner.id !== q.ownerId) return false;
    if (q.state !== undefined && it.state !== q.state) return false;
    if (from !== undefined || to !== undefined) {
      const t = Date.parse(it.startedAt);
      if (!Number.isFinite(t)) return false;
      if (from !== undefined && t < from) return false;
      if (to !== undefined && t > to) return false;
    }
    return true;
  });
}

export function statsOf(items: readonly InstanceSummary[]): InstanceStats {
  const byState = Object.fromEntries(INSTANCE_STATES.map((s) => [s, 0])) as Record<InstanceState, number>;
  for (const it of items) byState[it.state] += 1;
  return { total: items.length, byState };
}

export function pageOf<T>(items: readonly T[], page: number, size: number): T[] {
  const start = (Math.max(1, page) - 1) * Math.max(1, size);
  return items.slice(start, start + Math.max(1, size));
}