import { useState, useEffect } from 'react'
import UserNav from '../components/UserNav'
import { changePasswordApi, meApi, forgotPasswordApi } from '../services/auth'
import { useHandleAuthError } from '../hooks/useHandleAuthError'

export default function Profile() {
  const user = JSON.parse(localStorage.getItem('user') || '{}')
  const initials = `${(user.firstname || '?')[0]}${(user.lastname || '?')[0]}`.toUpperCase()
  const handleAuthError = useHandleAuthError()

  const [pwForm, setPwForm] = useState({ currentPassword: '', newPassword: '', confirmPassword: '' })
  const [showPw, setShowPw] = useState({ current: false, new: false, confirm: false })
  const [pwLoading, setPwLoading] = useState(false)
  const [pwError, setPwError] = useState('')
  const [pwSuccess, setPwSuccess] = useState(false)

  // Un compte créé via Google peut ne pas avoir de mot de passe : le
  // formulaire de modification n'aurait alors aucun sens. L'information vient
  // de l'API, car le profil stocké en localStorage ne la contient pas.
  const [hasPassword, setHasPassword] = useState(null)
  const [linkSending, setLinkSending] = useState(false)
  const [linkSent, setLinkSent] = useState(false)
  const [linkError, setLinkError] = useState('')

  useEffect(() => {
    meApi()
      .then((data) => setHasPassword(data.user.hasPassword))
      .catch((e) => {
        if (!handleAuthError(e)) setHasPassword(true)
      })
  }, [handleAuthError])

  const handleSendSetupLink = async () => {
    setLinkError('')
    setLinkSending(true)
    try {
      await forgotPasswordApi(user.email)
      setLinkSent(true)
    } catch (e) {
      if (!handleAuthError(e)) setLinkError(e.message)
    } finally {
      setLinkSending(false)
    }
  }

  const handlePwChange = (e) => setPwForm({ ...pwForm, [e.target.name]: e.target.value })

  const handlePwSubmit = async (e) => {
    e.preventDefault()
    setPwError('')
    setPwSuccess(false)

    if (pwForm.newPassword !== pwForm.confirmPassword) {
      setPwError('Les nouveaux mots de passe ne correspondent pas.')
      return
    }
    if (pwForm.newPassword.length < 8) {
      setPwError('Le nouveau mot de passe doit faire au moins 8 caractères.')
      return
    }

    setPwLoading(true)
    try {
      await changePasswordApi({ currentPassword: pwForm.currentPassword, newPassword: pwForm.newPassword })
      setPwSuccess(true)
      setPwForm({ currentPassword: '', newPassword: '', confirmPassword: '' })
    } catch (err) {
      if (!handleAuthError(err)) setPwError(err.message)
    } finally {
      setPwLoading(false)
    }
  }

  const EyeIcon = ({ visible }) => (
    <svg className="w-5 h-5" fill="none" stroke="currentColor" strokeWidth={1.5} viewBox="0 0 24 24">
      {visible
        ? <><path strokeLinecap="round" strokeLinejoin="round" d="M2.036 12.322a1.012 1.012 0 010-.639C3.423 7.51 7.36 4.5 12 4.5c4.638 0 8.573 3.007 9.963 7.178.07.207.07.431 0 .639C20.577 16.49 16.64 19.5 12 19.5c-4.638 0-8.573-3.007-9.963-7.178z" /><path strokeLinecap="round" strokeLinejoin="round" d="M15 12a3 3 0 11-6 0 3 3 0 016 0z" /></>
        : <path strokeLinecap="round" strokeLinejoin="round" d="M3.98 8.223A10.477 10.477 0 001.934 12C3.226 16.338 7.244 19.5 12 19.5c.993 0 1.953-.138 2.863-.395M6.228 6.228A10.45 10.45 0 0112 4.5c4.756 0 8.773 3.162 10.065 7.498a10.523 10.523 0 01-4.293 5.774M6.228 6.228L3 3m3.228 3.228l3.65 3.65m7.894 7.894L21 21m-3.228-3.228l-3.65-3.65m0 0a3 3 0 10-4.243-4.243m4.242 4.242L9.88 9.88" />
      }
    </svg>
  )

  return (
    <div className="min-h-screen bg-gray-50 flex flex-col px-8 py-12 max-w-lg mx-auto">
      <UserNav active="profile" />

      {/* Avatar */}
      <div className="mb-6">
        <div className="w-14 h-14 rounded-full bg-[#006B6B] flex items-center justify-center text-white text-lg font-bold">
          {initials}
        </div>
      </div>

      {/* Infos du compte (lecture seule) */}
      <div className="space-y-4 mb-8">
        <div>
          <label className="block text-xs font-medium text-gray-500 uppercase tracking-wider mb-1">Adresse email</label>
          <div className="w-full border border-gray-100 rounded-lg px-4 py-3 text-sm text-gray-500 bg-gray-50 cursor-not-allowed select-none">
            {user.email || '—'}
          </div>
        </div>
        <div>
          <label className="block text-xs font-medium text-gray-500 uppercase tracking-wider mb-1">Nom</label>
          <div className="w-full border border-gray-100 rounded-lg px-4 py-3 text-sm text-gray-500 bg-gray-50">
            {user.lastname || '—'}
          </div>
        </div>
        <div>
          <label className="block text-xs font-medium text-gray-500 uppercase tracking-wider mb-1">Prénom</label>
          <div className="w-full border border-gray-100 rounded-lg px-4 py-3 text-sm text-gray-500 bg-gray-50">
            {user.firstname || '—'}
          </div>
        </div>
      </div>

      {/* Séparateur */}
      <div className="border-t border-gray-100 mb-6" />

      {/* Section changement de mot de passe */}
      <div>
        <h2 className="text-sm font-semibold text-gray-800 mb-4">
          {hasPassword === false ? 'Définir un mot de passe' : 'Changer mon mot de passe'}
        </h2>

        {hasPassword === false && (
          <div className="px-4 py-4 rounded-lg bg-gray-50 border border-gray-200">
            <p className="text-sm text-gray-600">
              Votre compte a été créé avec Google et n&apos;a pas encore de mot de passe.
              Définissez-en un pour pouvoir aussi vous connecter avec votre email.
            </p>

            {linkSent ? (
              <p className="mt-3 text-sm text-green-700">
                Lien envoyé à {user.email}. Consultez votre boîte mail.
              </p>
            ) : (
              <button
                type="button"
                onClick={handleSendSetupLink}
                disabled={linkSending}
                className="mt-3 bg-[#006B6B] hover:bg-[#005959] disabled:opacity-50 text-white font-medium px-4 py-2.5 rounded-lg transition-colors text-sm"
              >
                {linkSending ? 'Envoi…' : 'Recevoir un lien par email'}
              </button>
            )}

            {linkError && <p className="mt-2 text-sm text-red-600">{linkError}</p>}
          </div>
        )}

        {hasPassword !== false && pwSuccess && (
          <div className="mb-4 px-4 py-3 rounded-lg bg-green-50 border border-green-200 text-green-700 text-sm flex items-center gap-2">
            <svg className="w-4 h-4 flex-shrink-0" fill="none" stroke="currentColor" strokeWidth={2.5} viewBox="0 0 24 24">
              <path strokeLinecap="round" strokeLinejoin="round" d="M5 13l4 4L19 7" />
            </svg>
            Mot de passe modifié avec succès.
          </div>
        )}

        {hasPassword !== false && pwError && (
          <div className="mb-4 px-4 py-3 rounded-lg bg-red-50 border border-red-200 text-red-600 text-sm">
            {pwError}
          </div>
        )}

        {hasPassword !== false && (
        <form onSubmit={handlePwSubmit} className="space-y-4">
          {[
            { name: 'currentPassword', label: 'Mot de passe actuel', key: 'current' },
            { name: 'newPassword',     label: 'Nouveau mot de passe', key: 'new' },
            { name: 'confirmPassword', label: 'Confirmer le nouveau mot de passe', key: 'confirm' },
          ].map(({ name, label, key }) => (
            <div key={name}>
              <label htmlFor={name} className="block text-sm font-medium text-gray-800 mb-1">{label}</label>
              <div className="relative">
                <input
                  type={showPw[key] ? 'text' : 'password'}
                  id={name}
                  name={name}
                  value={pwForm[name]}
                  onChange={handlePwChange}
                  required
                  placeholder="••••••••"
                  className="w-full border border-gray-200 rounded-lg px-4 py-3 pr-11 text-sm text-gray-700 placeholder-gray-500 focus:outline-none focus:ring-1 focus:ring-[#006B6B] focus:border-[#006B6B]"
                />
                <button
                  type="button"
                  onClick={() => setShowPw((s) => ({ ...s, [key]: !s[key] }))}
                  className="absolute right-3 top-1/2 -translate-y-1/2 text-gray-500 hover:text-gray-600"
                  aria-label="Afficher/masquer"
                >
                  <EyeIcon visible={showPw[key]} />
                </button>
              </div>
            </div>
          ))}

          <button
            type="submit"
            disabled={pwLoading}
            className="w-full bg-[#006B6B] hover:bg-[#005959] disabled:opacity-50 text-white font-medium py-3 rounded-lg transition-colors text-sm"
          >
            {pwLoading ? 'Modification…' : 'Modifier le mot de passe'}
          </button>
        </form>
        )}
      </div>
    </div>
  )
}