"use client"

import { useEffect, useMemo, useState } from "react"
import { Loader2, MailCheck, Server } from "lucide-react"
import { Button } from "@/components/ui/button"
import { Input } from "@/components/ui/input"
import { Label } from "@/components/ui/label"
import {
  Card,
  CardContent,
  CardDescription,
  CardHeader,
  CardTitle,
} from "@/components/ui/card"
import { ApiRequestError } from "@/lib/api/client"
import {
  useCheckMailAddress,
  useHostedMailStatus,
  useSetupHostedMailbox,
} from "@/lib/api/hooks/use-hosted-mail"
import { useAuthStore } from "@/lib/api/auth-store"

function suggestLocalPart(platformEmail: string | undefined, domain: string): string {
  if (!platformEmail?.includes("@")) return ""
  const [local, emailDomain] = platformEmail.split("@")
  if (!local) return ""
  if (emailDomain?.toLowerCase() === domain.toLowerCase()) {
    return local.toLowerCase()
  }
  return local.toLowerCase().replace(/[^a-z0-9._+-]/g, "")
}

function setupErrorMessage(error: unknown): string {
  if (error instanceof ApiRequestError) {
    switch (error.code) {
      case "address_taken":
        return "Cette adresse est déjà utilisée."
      case "domain_not_active":
        return "Le domaine mail n'est pas encore actif."
    }
    return error.message
  }
  if (error instanceof Error) return error.message
  return "Échec de la configuration."
}

export function HostedMailSetupCard() {
  const platformEmail = useAuthStore((s) => s.user?.email)
  const { data: status, isPending } = useHostedMailStatus()
  const setup = useSetupHostedMailbox()

  const domain = status?.platform_domain ?? ""
  const alreadyConnected = Boolean(
    status?.hosted_mail_account_id || status?.mailbox?.mail_account_id
  )
  const connectedEmail =
    status?.hosted_mail_account_email ?? status?.mailbox?.email ?? ""

  const [localPart, setLocalPart] = useState("")
  const [displayName, setDisplayName] = useState("")
  const [password, setPassword] = useState("")
  const [confirmPassword, setConfirmPassword] = useState("")

  useEffect(() => {
    if (!domain || localPart) return
    const suggested = suggestLocalPart(platformEmail, domain)
    if (suggested) setLocalPart(suggested)
  }, [domain, localPart, platformEmail])

  const fullEmail = useMemo(() => {
    const local = localPart.trim().toLowerCase()
    return local && domain ? `${local}@${domain}` : ""
  }, [localPart, domain])

  const addressCheck = useCheckMailAddress(localPart.trim(), domain)
  const addressTaken =
    addressCheck.data?.available === false &&
    addressCheck.data.reason !== "hosted_mail_disabled"

  const passwordsMatch = password === confirmPassword
  const passwordOk = password.length >= 8
  const canSubmit =
    !setup.isPending &&
    localPart.trim().length > 0 &&
    passwordOk &&
    passwordsMatch &&
    addressCheck.data?.available !== false

  if (isPending || !status?.enabled) return null

  const endpoints = status.endpoints

  async function handleSubmit() {
    if (!canSubmit) return
    try {
      await setup.mutateAsync({
        local_part: localPart.trim().toLowerCase(),
        password,
        display_name: displayName.trim() || undefined,
      })
      setPassword("")
      setConfirmPassword("")
    } catch {
      /* message below */
    }
  }

  return (
    <Card className="border-primary/20 bg-primary/[0.03]">
      <CardHeader>
        <div className="flex items-start gap-3">
          <Server className="mt-0.5 size-5 shrink-0 text-primary" />
          <div>
            <CardTitle className="text-base">Mail hébergé Ultimail (Stalwart)</CardTitle>
            <CardDescription>
              Créez ou connectez votre boîte @{domain} — IMAP/SMTP préconfigurés, sans saisie
              manuelle des serveurs.
            </CardDescription>
          </div>
        </div>
      </CardHeader>
      <CardContent className="space-y-4">
        {endpoints ? (
          <p className="text-xs text-muted-foreground">
            Serveurs : IMAP {endpoints.imap_host}:{endpoints.imap_port}
            {endpoints.imap_tls ? " (TLS)" : ""} · SMTP {endpoints.smtp_host}:{endpoints.smtp_port}
            {endpoints.smtp_tls ? " (TLS)" : ""}
          </p>
        ) : null}

        {alreadyConnected ? (
          <div className="flex items-start gap-2 rounded-lg border border-border bg-background px-3 py-2">
            <MailCheck className="mt-0.5 size-4 shrink-0 text-green-600 dark:text-green-500" />
            <div>
              <p className="text-sm font-medium">Boîte hébergée connectée</p>
              <p className="text-sm text-muted-foreground">{connectedEmail}</p>
            </div>
          </div>
        ) : (
          <div className="space-y-4 max-w-lg">
            <div className="grid gap-3 sm:grid-cols-2">
              <div className="space-y-1.5 sm:col-span-2">
                <Label htmlFor="hosted-local-part">Adresse mail</Label>
                <div className="flex items-center gap-2">
                  <Input
                    id="hosted-local-part"
                    value={localPart}
                    autoComplete="username"
                    placeholder="prenom.nom"
                    onChange={(e) => setLocalPart(e.target.value)}
                  />
                  <span className="shrink-0 text-sm text-muted-foreground">@{domain}</span>
                </div>
                {fullEmail ? (
                  <p className="text-xs text-muted-foreground">{fullEmail}</p>
                ) : null}
                {addressCheck.isFetching ? (
                  <p className="text-xs text-muted-foreground">Vérification de la disponibilité…</p>
                ) : addressTaken ? (
                  <p className="text-xs text-destructive">Adresse déjà prise.</p>
                ) : addressCheck.data?.available === true && localPart.trim() ? (
                  <p className="text-xs text-green-600 dark:text-green-500">Adresse disponible.</p>
                ) : null}
              </div>
              <div className="space-y-1.5">
                <Label htmlFor="hosted-display-name">Nom affiché</Label>
                <Input
                  id="hosted-display-name"
                  value={displayName}
                  placeholder="Optionnel"
                  onChange={(e) => setDisplayName(e.target.value)}
                />
              </div>
              <div className="space-y-1.5">
                <Label htmlFor="hosted-password">Mot de passe boîte</Label>
                <Input
                  id="hosted-password"
                  type="password"
                  value={password}
                  autoComplete="new-password"
                  onChange={(e) => setPassword(e.target.value)}
                />
              </div>
              <div className="space-y-1.5 sm:col-span-2">
                <Label htmlFor="hosted-password-confirm">Confirmer le mot de passe</Label>
                <Input
                  id="hosted-password-confirm"
                  type="password"
                  value={confirmPassword}
                  autoComplete="new-password"
                  onChange={(e) => setConfirmPassword(e.target.value)}
                />
                {password && !passwordOk ? (
                  <p className="text-xs text-destructive">8 caractères minimum.</p>
                ) : null}
                {confirmPassword && !passwordsMatch ? (
                  <p className="text-xs text-destructive">Les mots de passe ne correspondent pas.</p>
                ) : null}
              </div>
            </div>

            {setup.isError ? (
              <p className="text-sm text-destructive">{setupErrorMessage(setup.error)}</p>
            ) : null}
            {setup.isSuccess ? (
              <p className="text-sm text-green-600 dark:text-green-500">
                Boîte configurée — synchronisation IMAP en cours.
              </p>
            ) : null}

            <Button type="button" disabled={!canSubmit} onClick={() => void handleSubmit()}>
              {setup.isPending ? (
                <>
                  <Loader2 className="mr-2 size-4 animate-spin" />
                  Configuration…
                </>
              ) : (
                "Activer ma boîte hébergée"
              )}
            </Button>
          </div>
        )}
      </CardContent>
    </Card>
  )
}