import type { TodoItem, DayTodo } from './types.js'

export const parseTodoContent = (content: string): DayTodo[] => {
  const lines = content.split('\n')
  const result: DayTodo[] = []
  let currentDate: string | null = null
  let currentItems: TodoItem[] = []
  let itemId = 0

  for (const line of lines) {
    const dateMatch = line.match(/^##\s*(\d{4}-\d{2}-\d{2})/)
    if (dateMatch) {
      if (currentDate) {
        result.push({ date: currentDate, items: currentItems })
      }
      currentDate = dateMatch[1]
      currentItems = []
    } else if (currentDate) {
      const todoMatch = line.match(/^- (√|○) (.*)$/)
      if (todoMatch) {
        currentItems.push({
          id: `${currentDate}-${itemId++}`,
          content: todoMatch[2],
          completed: todoMatch[1] === '√'
        })
      }
    }
  }

  if (currentDate) {
    result.push({ date: currentDate, items: currentItems })
  }

  return result
}

export const generateTodoContent = (dayTodos: DayTodo[]): string => {
  const lines: string[] = []
  const sortedDays = [...dayTodos].sort((a, b) => a.date.localeCompare(b.date))

  for (const day of sortedDays) {
    lines.push(`## ${day.date}`)
    for (const item of day.items) {
      const checkbox = item.completed ? '√' : '○'
      lines.push(`- ${checkbox} ${item.content}`)
    }
    lines.push('')
  }

  return lines.join('\n').trimEnd()
}