import { useState } from 'react'
import {
  MILESTONE_STATUSES,
  MILESTONE_STATUS_LABELS,
} from '../constants/status.js'
import { StatusBadge } from './StatusBadge.jsx'
import { EmptyState } from './EmptyState.jsx'

function formatDate(value) {
  if (!value) return null
  try {
    return new Date(value.includes('T') ? value : `${value}T12:00:00`).toLocaleDateString(
      'de-DE'
    )
  } catch {
    return value
  }
}

export function MilestonesSection({
  milestones,
  canManage,
  onCreate,
  onUpdateStatus,
  onDelete,
  busy,
  compact = false,
}) {
  const [title, setTitle] = useState('')
  const [goalDescription, setGoalDescription] = useState('')
  const [targetDate, setTargetDate] = useState('')
  const [showForm, setShowForm] = useState(false)

  async function handleSubmit(e) {
    e.preventDefault()
    if (!title.trim()) return
    await onCreate({
      title: title.trim(),
      goal_description: goalDescription.trim(),
      target_date: targetDate || undefined,
    })
    setTitle('')
    setGoalDescription('')
    setTargetDate('')
    setShowForm(false)
  }

  return (
    <section className={`card${compact ? ' card--secondary' : ''}`}>
      <div className="section-header">
        <div>
          <h2>Meilensteine</h2>
          <p className="section-lead muted">
            Überprüfbare Zielpunkte — kein Task. Ziel und Termin machen den Horizont steuerbar.
          </p>
        </div>
        {canManage && (
          <button
            type="button"
            className="btn btn-primary btn-block-mobile"
            onClick={() => setShowForm((v) => !v)}
          >
            {showForm ? 'Abbrechen' : 'Meilenstein'}
          </button>
        )}
      </div>

      {showForm && canManage && (
        <form className="inline-form-block milestone-form" onSubmit={handleSubmit}>
          <label>
            Titel
            <input
              value={title}
              onChange={(e) => setTitle(e.target.value)}
              maxLength={255}
              required
              placeholder="z. B. MVP nutzbar im Alltag"
            />
          </label>
          <label>
            Ziel / Definition of Done
            <textarea
              value={goalDescription}
              onChange={(e) => setGoalDescription(e.target.value)}
              rows={3}
              placeholder="Woran erkennst du, dass dieser Meilenstein erreicht ist?"
            />
          </label>
          <label>
            Zieltermin
            <input
              type="date"
              value={targetDate}
              onChange={(e) => setTargetDate(e.target.value)}
            />
          </label>
          <button type="submit" className="btn btn-primary" disabled={busy}>
            Anlegen
          </button>
        </form>
      )}

      {milestones.length === 0 && (
        <EmptyState message="Noch keine Meilensteine — strukturiere das Vorhaben in überprüfbare Zielpunkte." />
      )}

      <ul className="item-list milestone-list">
        {milestones.map((milestone) => (
          <li key={milestone.id} className="list-item card-list-item milestone-list-item">
            <div className="list-item-main">
              <strong>{milestone.title}</strong>
              {milestone.goal_description && (
                <p className="list-item-desc">{milestone.goal_description}</p>
              )}
              {milestone.target_date && (
                <p className="muted list-item-sub">
                  Zieltermin: {formatDate(milestone.target_date)}
                </p>
              )}
            </div>
            <div className="list-item-meta action-controls">
              <StatusBadge kind="milestone" status={milestone.status} />
              {canManage && (
                <>
                  <select
                    className="inline-select"
                    value={milestone.status}
                    onChange={(e) => onUpdateStatus(milestone.id, e.target.value)}
                    aria-label="Meilenstein-Status"
                  >
                    {MILESTONE_STATUSES.map((s) => (
                      <option key={s} value={s}>
                        {MILESTONE_STATUS_LABELS[s]}
                      </option>
                    ))}
                  </select>
                  <button
                    type="button"
                    className="btn btn-secondary"
                    onClick={() => onDelete(milestone.id)}
                  >
                    Löschen
                  </button>
                </>
              )}
            </div>
          </li>
        ))}
      </ul>
    </section>
  )
}