// 任务模块: 保留选项的可见性过滤 (T-FL-*)
// 前端 src/pages/task/date.js 有一份同口径实现, 用于即时过滤; 后端用于统计/兜底
import { isVisibleByRetention } from './date.js'

/**
 * 按"任务所属列"的保留选项过滤任务列表 (T-FL-11)
 * @param {object[]} tasks   任务(需含 status / doneAt / columnId)
 * @param {object[]} columns 列(需含 id / retention)
 */
export function filterVisible(tasks, columns, now = new Date()) {
  const retentionById = new Map((columns || []).map((c) => [c.id, c.retention || 'forever']))
  return (tasks || []).filter((t) => {
    const opt = retentionById.get(t.columnId) || 'forever'
    return isVisibleByRetention(t, opt, now)
  })
}

/** 单条判定, 供详情接口复用 */
export function isTaskVisible(task, columns, now = new Date()) {
  const col = (columns || []).find((c) => c.id === task.columnId)
  return isVisibleByRetention(task, col?.retention || 'forever', now)
}

/** 列内计数: 过滤后条数 (T-FL-14 计数与展示同源) */
export function countByColumn(tasks, columns, now = new Date()) {
  const visible = filterVisible(tasks, columns, now)
  const out = {}
  for (const c of columns || []) out[c.id] = 0
  for (const t of visible) out[t.columnId] = (out[t.columnId] || 0) + 1
  return out
}