import { useState, useEffect, useContext } from 'react'
import { Settings as SettingsIcon, Play, CheckCircle, Languages, Coins, Upload, Tag, Plus, Pencil, Trash2, X } from 'lucide-react'
import { api } from '../utils/api'
import { useLanguage } from '../i18n/LanguageContext'
import { useToast } from '../components/ToastContainer'
import { CURRENCIES } from '../i18n/LanguageContext'
import { AppContext } from '../App'
import { useAuth } from '../contexts/AuthContext'
import Modal from '../components/Modal'

const ROLE_COLORS = [
  '#3B82F6', '#10B981', '#F59E0B', '#EF4444', '#8B5CF6',
  '#EC4899', '#06B6D4', '#F97316', '#6366F1', '#14B8A6',
]

export default function Settings() {
  const { t, lang, setLang, currency, setCurrency } = useLanguage()
  const toast = useToast()
  const { user } = useAuth()
  const { roles, loadRoles } = useContext(AppContext)
  const [restarting, setRestarting] = useState(false)
  const [success, setSuccess] = useState(false)
  const [maxSizeMB, setMaxSizeMB] = useState(50)
  const [sizeSaving, setSizeSaving] = useState(false)
  const [sizeSaved, setSizeSaved] = useState(false)

  useEffect(() => {
    api.get('/settings/app').then(s => setMaxSizeMB(s.uploadMaxSizeMB || 50)).catch(() => {})
  }, [])

  const handleSaveMaxSize = async () => {
    setSizeSaving(true)
    setSizeSaved(false)
    try {
      const res = await api.patch('/settings/app', { uploadMaxSizeMB: maxSizeMB })
      setMaxSizeMB(res.uploadMaxSizeMB)
      setSizeSaved(true)
      setTimeout(() => setSizeSaved(false), 2000)
    } catch (err) {
      toast.error(err.message || t('settings.saveFailed'))
    } finally {
      setSizeSaving(false)
    }
  }

  const handleRestartTutorial = async () => {
    setRestarting(true)
    setSuccess(false)
    try {
      await api.patch('/users/me/tutorial', { completed: false })
      setSuccess(true)
      setTimeout(() => {
        window.location.reload() // Reload to trigger tutorial
      }, 1500)
    } catch (err) {
      console.error('Failed to restart tutorial:', err)
      toast.error(t('settings.restartTutorialFailed'))
    } finally {
      setRestarting(false)
    }
  }

  return (
    <div className="space-y-6 animate-fade-in max-w-3xl">
      <p className="text-sm text-text-tertiary">{t('settings.preferences')}</p>

      {/* General Settings */}
      <div className="bg-white rounded-xl border border-border overflow-hidden">
        <div className="px-6 py-4 border-b border-border">
          <h2 className="text-lg font-semibold text-text-primary">{t('settings.general')}</h2>
        </div>
        <div className="p-6 space-y-4">
          {/* Language Selector */}
          <div>
            <label className="block text-sm font-medium text-text-primary mb-2 flex items-center gap-2">
              <Languages className="w-4 h-4" />
              {t('settings.language')}
            </label>
            <select
              value={lang}
              onChange={(e) => setLang(e.target.value)}
              className="w-full max-w-xs px-4 py-2.5 border border-border rounded-lg text-sm focus:outline-none focus:ring-2 focus:ring-brand-primary/20 focus:border-brand-primary bg-white"
            >
              <option value="en">{t('settings.english')}</option>
              <option value="ar">{t('settings.arabic')}</option>
            </select>
          </div>

          {/* Currency Selector */}
          <div>
            <label className="block text-sm font-medium text-text-primary mb-2 flex items-center gap-2">
              <Coins className="w-4 h-4" />
              {t('settings.currency')}
            </label>
            <select
              value={currency}
              onChange={(e) => setCurrency(e.target.value)}
              className="w-full max-w-xs px-4 py-2.5 border border-border rounded-lg text-sm focus:outline-none focus:ring-2 focus:ring-brand-primary/20 focus:border-brand-primary bg-white"
            >
              {CURRENCIES.map(c => (
                <option key={c.code} value={c.code}>
                  {c.symbol} — {lang === 'ar' ? c.labelAr : c.labelEn}
                </option>
              ))}
            </select>
            <p className="text-xs text-text-tertiary mt-1.5">{t('settings.currencyHint')}</p>
          </div>
        </div>
      </div>

      {/* Uploads Section */}
      <div className="bg-white rounded-xl border border-border overflow-hidden">
        <div className="px-6 py-4 border-b border-border">
          <h2 className="text-lg font-semibold text-text-primary flex items-center gap-2">
            <Upload className="w-5 h-5 text-brand-primary" />
            {t('settings.uploads')}
          </h2>
        </div>
        <div className="p-6 space-y-4">
          <div>
            <label className="block text-sm font-medium text-text-primary mb-2">
              {t('settings.maxFileSize')}
            </label>
            <div className="flex items-center gap-3">
              <input
                type="number"
                min="1"
                max="500"
                value={maxSizeMB}
                onChange={(e) => setMaxSizeMB(Number(e.target.value))}
                className="w-24 px-3 py-2.5 border border-border rounded-lg text-sm focus:outline-none focus:ring-2 focus:ring-brand-primary/20 focus:border-brand-primary bg-white"
              />
              <span className="text-sm text-text-secondary">{t('settings.mb')}</span>
              <button
                onClick={handleSaveMaxSize}
                disabled={sizeSaving}
                className="px-4 py-2.5 bg-brand-primary text-white rounded-lg text-sm font-medium hover:bg-brand-primary-light disabled:opacity-50 transition-colors"
              >
                {sizeSaved ? (
                  <span className="flex items-center gap-1.5"><CheckCircle className="w-4 h-4" />{t('settings.saved')}</span>
                ) : sizeSaving ? '...' : t('common.save')}
              </button>
            </div>
            <p className="text-xs text-text-tertiary mt-1.5">{t('settings.maxFileSizeHint')}</p>
          </div>
        </div>
      </div>

      {/* Tutorial Section */}
      <div className="bg-white rounded-xl border border-border overflow-hidden">
        <div className="px-6 py-4 border-b border-border">
          <h2 className="text-lg font-semibold text-text-primary">{t('settings.onboardingTutorial')}</h2>
        </div>
        <div className="p-6 space-y-4">
          <p className="text-sm text-text-secondary">
            {t('settings.tutorialDesc')}
          </p>
          <button
            onClick={handleRestartTutorial}
            disabled={restarting || success}
            className="flex items-center gap-2 px-4 py-2.5 bg-brand-primary text-white rounded-lg text-sm font-medium hover:bg-brand-primary-light disabled:opacity-50 disabled:cursor-not-allowed shadow-sm transition-colors"
          >
            {success ? (
              <>
                <CheckCircle className="w-4 h-4" />
                {t('settings.tutorialRestarted')}
              </>
            ) : (
              <>
                <Play className="w-4 h-4" />
                {restarting ? t('settings.restarting') : t('settings.restartTutorial')}
              </>
            )}
          </button>
          {success && (
            <p className="text-xs text-emerald-600 font-medium">
              {t('settings.reloadingPage')}
            </p>
          )}
        </div>
      </div>

      {/* Roles Management (Superadmin only) */}
      {user?.role === 'superadmin' && <RolesSection roles={roles} loadRoles={loadRoles} t={t} toast={toast} />}
    </div>
  )
}

function RolesSection({ roles, loadRoles, t, toast }) {
  const [editingRole, setEditingRole] = useState(null)
  const [showAddModal, setShowAddModal] = useState(false)
  const [modalForm, setModalForm] = useState({ name: '', color: ROLE_COLORS[0] })
  const [saving, setSaving] = useState(false)

  const openAddModal = () => {
    setModalForm({ name: '', color: ROLE_COLORS[roles.length % ROLE_COLORS.length] })
    setShowAddModal(true)
  }

  const handleCreate = async () => {
    setSaving(true)
    try {
      await api.post('/roles', { name: modalForm.name, color: modalForm.color })
      await loadRoles()
      setShowAddModal(false)
    } catch (err) {
      toast.error(err.message || t('common.error'))
    } finally {
      setSaving(false)
    }
  }

  const handleSave = async (role) => {
    setSaving(true)
    try {
      await api.patch(`/roles/${role.Id || role.id}`, { name: role.name, color: role.color })
      await loadRoles()
      setEditingRole(null)
    } catch (err) {
      toast.error(err.message || t('common.error'))
    } finally {
      setSaving(false)
    }
  }

  const handleDelete = async (role) => {
    if (!confirm(t('settings.deleteRoleConfirm'))) return
    try {
      await api.delete(`/roles/${role.Id || role.id}`)
      await loadRoles()
    } catch (err) {
      toast.error(err.message || t('common.error'))
    }
  }

  return (
    <>
      <div className="bg-white dark:bg-surface-primary rounded-xl border border-border overflow-hidden">
        <div className="px-6 py-4 border-b border-border flex items-center justify-between">
          <h2 className="text-lg font-semibold text-text-primary flex items-center gap-2">
            <Tag className="w-5 h-5 text-brand-primary" />
            {t('settings.roles')}
          </h2>
          <button
            onClick={openAddModal}
            className="flex items-center gap-1.5 px-3 py-1.5 text-sm font-medium bg-brand-primary text-white rounded-lg hover:bg-brand-primary-light transition-colors"
          >
            <Plus className="w-4 h-4" />
            {t('settings.addRole')}
          </button>
        </div>
        <div className="p-6">
          <p className="text-sm text-text-tertiary mb-4">{t('settings.rolesDesc')}</p>
          <div className="space-y-2">
            {roles.map(role => (
              <div key={role.Id || role.id} className="flex items-center gap-3 p-3 rounded-lg border border-border hover:bg-surface-secondary transition-colors">
                {editingRole && (editingRole.Id || editingRole.id) === (role.Id || role.id) ? (
                  <div className="flex items-center gap-3 flex-1">
                    <input type="color" value={editingRole.color || '#94A3B8'} onChange={e => setEditingRole({ ...editingRole, color: e.target.value })}
                      className="w-8 h-8 rounded-lg border border-border cursor-pointer" />
                    <input type="text" value={editingRole.name} onChange={e => setEditingRole({ ...editingRole, name: e.target.value })}
                      placeholder={t('settings.roleName')} autoFocus
                      className="flex-1 px-3 py-1.5 text-sm border border-border rounded-lg focus:outline-none focus:ring-2 focus:ring-brand-primary/20 focus:border-brand-primary" />
                    <button onClick={() => handleSave(editingRole)} disabled={!editingRole.name || saving}
                      className="px-3 py-1.5 text-sm font-medium bg-brand-primary text-white rounded-lg hover:bg-brand-primary-light disabled:opacity-50 transition-colors">
                      {saving ? '...' : t('common.save')}
                    </button>
                    <button onClick={() => setEditingRole(null)} className="p-1.5 text-text-tertiary hover:text-text-primary rounded-lg hover:bg-surface-tertiary transition-colors">
                      <X className="w-4 h-4" />
                    </button>
                  </div>
                ) : (
                  <>
                    <div className="w-4 h-4 rounded-full shrink-0" style={{ backgroundColor: role.color || '#94A3B8' }} />
                    <span className="flex-1 text-sm font-medium text-text-primary">{role.name}</span>
                    <button onClick={() => setEditingRole({ ...role })} className="p-1.5 text-text-tertiary hover:text-brand-primary rounded-lg hover:bg-surface-tertiary transition-colors">
                      <Pencil className="w-4 h-4" />
                    </button>
                    <button onClick={() => handleDelete(role)} className="p-1.5 text-text-tertiary hover:text-red-500 rounded-lg hover:bg-red-50 transition-colors">
                      <Trash2 className="w-4 h-4" />
                    </button>
                  </>
                )}
              </div>
            ))}
            {roles.length === 0 && (
              <p className="text-sm text-text-tertiary text-center py-6">{t('settings.noRoles')}</p>
            )}
          </div>
        </div>
      </div>

      <Modal isOpen={showAddModal} onClose={() => setShowAddModal(false)} title={t('settings.addRole')} size="sm">
        <div className="space-y-4">
          <div>
            <label className="block text-xs font-medium text-text-tertiary mb-1">{t('settings.roleName')}</label>
            <input type="text" value={modalForm.name} onChange={e => setModalForm(f => ({ ...f, name: e.target.value }))}
              className="w-full px-3 py-2 text-sm border border-border rounded-lg focus:outline-none focus:ring-2 focus:ring-brand-primary/20 focus:border-brand-primary"
              placeholder={t('settings.roleName')} autoFocus />
          </div>
          <div>
            <label className="block text-xs font-medium text-text-tertiary mb-1">{t('settings.roleColor') || 'Color'}</label>
            <div className="flex items-center gap-3">
              <input type="color" value={modalForm.color} onChange={e => setModalForm(f => ({ ...f, color: e.target.value }))}
                className="w-10 h-10 rounded-lg border border-border cursor-pointer" />
              <div className="flex flex-wrap gap-1.5">
                {ROLE_COLORS.map(c => (
                  <button key={c} type="button" onClick={() => setModalForm(f => ({ ...f, color: c }))}
                    className={`w-6 h-6 rounded-full border-2 transition-colors ${modalForm.color === c ? 'border-text-primary scale-110' : 'border-transparent'}`}
                    style={{ backgroundColor: c }} />
                ))}
              </div>
            </div>
          </div>
          <button onClick={handleCreate} disabled={!modalForm.name || saving}
            className={`w-full px-4 py-2.5 bg-brand-primary text-white rounded-lg text-sm font-medium hover:bg-brand-primary-light disabled:opacity-50 disabled:cursor-not-allowed shadow-sm ${saving ? 'btn-loading' : ''}`}>
            {t('settings.addRole')}
          </button>
        </div>
      </Modal>
    </>
  )
}
