import type { Priority } from './derive';

export type DevTaskStatus = 'todo' | 'in_progress' | 'testing' | 'submitted' | 'done';

export interface DevTask {
  id: string;
  taskNo: string;
  requirementId: string;
  title: string;
  description?: string;
  categoryId: string;
  assigneeId: string;
  reviewerId?: string;
  priority: Priority;
  estimateHours: number;
  actualHours: number;
  startDate?: string;
  dueDate?: string;
  completedAt?: string;
  status: DevTaskStatus;
  isBlocked: boolean;
  blockReason?: string;
  blockedById?: string;
  predecessorIds?: string[];
  riskLevel?: 'low' | 'medium' | 'high';
  overdueReason?: string;
  createdBy: string;
  createdAt: string;
  updatedAt: string;
}

export const DEV_TASK_STATUS_LABEL: Record<DevTaskStatus, string> = {
  todo: '待开发',
  in_progress: '开发中',
  testing: '自测',
  submitted: '提测',
  done: '已完成',
};

export const DEV_TASK_STATUS_COLOR: Record<DevTaskStatus, string> = {
  todo: 'bg-zinc-100 text-zinc-600',
  in_progress: 'bg-blue-50 text-blue-600',
  testing: 'bg-purple-50 text-purple-600',
  submitted: 'bg-orange-50 text-orange-600',
  done: 'bg-emerald-50 text-emerald-600',
};

export const STATUS_PROGRESS: Record<DevTaskStatus, number> = {
  todo: 0,
  in_progress: 50,
  testing: 80,
  submitted: 90,
  done: 100,
};

export const ALLOWED_TRANSITIONS: Record<DevTaskStatus, DevTaskStatus[]> = {
  todo: ['in_progress'],
  in_progress: ['testing'],
  testing: ['submitted', 'in_progress'],
  submitted: ['done', 'in_progress'],
  done: [],
};

export function canTransition(from: DevTaskStatus, to: DevTaskStatus): boolean {
  return ALLOWED_TRANSITIONS[from].includes(to);
}

export function calcTaskProgress(task: DevTask): number {
  return STATUS_PROGRESS[task.status];
}

export function calcGroupProgress(tasks: DevTask[]): number {
  if (tasks.length === 0) return 0;
  const totalEstimate = tasks.reduce((sum, t) => sum + t.estimateHours, 0);
  if (totalEstimate === 0) return 0;
  const weighted = tasks.reduce((sum, t) => sum + t.estimateHours * STATUS_PROGRESS[t.status], 0);
  return Math.round(weighted / totalEstimate);
}

export function formatHours(hours: number): string {
  if (hours < 8) return `${hours}h`;
  const days = Math.floor(hours / 8);
  const remainder = hours % 8;
  if (remainder === 0) return `${hours}h（${days}人天）`;
  return `${hours}h（≈${days}人天）`;
}

export function calcActualHoursByDates(startDate?: string, completedAt?: string): number {
  if (!startDate) return 0;
  const end = completedAt || new Date().toISOString().slice(0, 10);
  const start = new Date(startDate);
  const endDate = new Date(end);
  if (isNaN(start.getTime()) || isNaN(endDate.getTime()) || endDate < start) return 0;
  let workDays = 0;
  const current = new Date(start);
  while (current <= endDate) {
    const day = current.getDay();
    if (day !== 0 && day !== 6) workDays++;
    current.setDate(current.getDate() + 1);
  }
  return workDays * 8;
}

export function generateTaskNo(existingTasks: DevTask[]): string {
  const maxNum = existingTasks.reduce((max, t) => {
    const num = parseInt(t.taskNo.replace('DEV-', ''), 10);
    return isNaN(num) ? max : Math.max(max, num);
  }, 0);
  return `DEV-${String(maxNum + 1).padStart(3, '0')}`;
}