import React, { useCallback, useEffect, useMemo, useRef, useState } from "react";

import { Alert, Avatar, Box, Button, Chip, Divider, Paper, TextField, Typography } from "@mui/material";

import DeleteOutlineIcon from "@mui/icons-material/DeleteOutline";
import PhotoCameraOutlinedIcon from "@mui/icons-material/PhotoCameraOutlined";

import { api, getApiErrorMessage } from "../api";
import GoogleAuthCard from "../components/GoogleAuthCard";
import MicrosoftAuthCard from "../components/MicrosoftAuthCard";
import AuthStatusCard from "../components/AuthStatusCard";
import TwoFactorSettingsCard from "../components/TwoFactorSettingsCard";
import SessionsSettingsCard from "../components/SessionsSettingsCard";
import CropImageDialog from "../components/CropImageDialog";
import { useToast } from "../toast";
import { useI18n } from "../i18n/I18nProvider";
import { parseStructuredCvJson } from "../profileCv";
import { getUserScopedStorageKey } from "../auth";

type MeResponse = {
  provider?: "local" | "google" | "external";
  id?: string;
  email?: string;
  userName?: string;
  firstName?: string;
  lastName?: string;
  displayName?: string;
  profileCvText?: string;
  profileCvStructureJson?: string;
  avatarImageDataUrl?: string;
  roles?: string[];
  googleLink?: {
    linked: boolean;
    email?: string | null;
    linkedAt?: string | null;
  } | null;
};

type PendingEmailChange = {
  pendingEmail?: string | null;
  requestedAtUtc?: string | null;
};

const AVATAR_UPLOAD_ACCEPT = "image/png,image/jpeg,image/webp";

function initialsFrom(values: Array<string | undefined>) {
  const joined = values.map((x) => (x ?? "").trim()).filter(Boolean);
  if (joined.length === 0) return "?";
  if (joined.length === 1) {
    const parts = joined[0].split(/[\s@._-]+/).filter(Boolean);
    if (parts.length === 1) return parts[0].slice(0, 2).toUpperCase();
    return (parts[0][0] + parts[1][0]).toUpperCase();
  }
  return (joined[0][0] + joined[1][0]).toUpperCase();
}

// ProfilePage backs /profile: account identity + security + preferences. The master career
// profile lives in CareerProfilePage (/career). Split in Phase 2.2. Saves only identity fields
// (partial update), never the master profile.
export default function ProfilePage() {
  // Retained so the shared JSX reads identically; hardcoded for /profile.
  const careerOnly = false;
  const { toast } = useToast();
  const { t } = useI18n();
  const avatarInputRef = useRef<HTMLInputElement | null>(null);
  const [me, setMe] = useState<MeResponse | null>(null);
  const [loading, setLoading] = useState(false);
  const [loadError, setLoadError] = useState<string | null>(null);
  const [uploadingAvatar, setUploadingAvatar] = useState(false);
  const [avatarFile, setAvatarFile] = useState<File | null>(null);
  const [cropOpen, setCropOpen] = useState(false);

  const [email, setEmail] = useState("");
  const [pendingEmail, setPendingEmail] = useState<string | null>(null);
  const [emailChangePassword, setEmailChangePassword] = useState("");
  const [userName, setUserName] = useState("");
  const [firstName, setFirstName] = useState("");
  const [lastName, setLastName] = useState("");
  const [displayName, setDisplayName] = useState("");
  const [headline, setHeadline] = useState("");
  const [profileCvText, setProfileCvText] = useState("");
  const [currentPassword, setCurrentPassword] = useState("");
  const [newPassword, setNewPassword] = useState("");


  const loadProfile = useCallback(async () => {
    setLoading(true);
    try {
      // /profile only needs the account row. The master-profile data (runs, structured CV,
      // saved jobs) is loaded by CareerProfilePage on /career.
      const r = await api.get<MeResponse>("/auth/me");
      setMe(r.data);
      setEmail(r.data?.email ?? "");
      setUserName(r.data?.userName ?? "");
      setFirstName(r.data?.firstName ?? "");
      setLastName(r.data?.lastName ?? "");
      setDisplayName(r.data?.displayName ?? "");
      setProfileCvText(r.data?.profileCvText ?? "");
      const persistedHeadline = parseStructuredCvJson(r.data?.profileCvStructureJson).contact.headline;
      const userKey = r.data?.id || r.data?.email || r.data?.userName || "anon";
      setHeadline(persistedHeadline ?? window.localStorage.getItem(getUserScopedStorageKey("profileHeadline", userKey)) ?? "");
      if (r.data?.provider === "local") {
        const pending = await api.get<PendingEmailChange>("/auth/email-change");
        setPendingEmail(pending.data?.pendingEmail ?? null);
      } else {
        setPendingEmail(null);
      }
      setLoadError(null);
    } catch (error: any) {
      setMe(null);
      setLoadError(String(error?.response?.data || error?.message || "Unable to load profile right now."));
    } finally {
      setLoading(false);
    }
  }, []);

  useEffect(() => {
    void loadProfile();
  }, [loadProfile]);

  const initials = useMemo(() => initialsFrom([me?.displayName, me?.firstName, me?.lastName, me?.userName, me?.email]), [me]);
  const isLocal = me?.provider === "local";
  const fullName = [me?.firstName, me?.lastName].filter(Boolean).join(" ");
  const cvWordCount = profileCvText.trim() ? profileCvText.trim().split(/\s+/).length : 0;

  const providerLabel = me?.provider === "local" ? t("profileLocalAccount") : me?.provider === "google" ? t("profileGoogleSession") : t("profileExternalSession");
  const googleLabel = me?.googleLink?.linked
    ? me.googleLink.email
      ? t("profileGoogleLinkedWithEmail", { email: me.googleLink.email })
      : t("profileGoogleLinked")
    : t("profileGoogleNotLinked");
  const cvLabel = profileCvText.trim() ? t("profileCvReady", { count: cvWordCount }) : t("profileCvMissing");

  return (
    <Paper sx={{ mt: 0, p: 2.5, borderRadius: 4, border: "none", boxShadow: "0px 1px 2px 0px rgba(15,23,42,0.04), 0px 8px 24px -12px rgba(15,23,42,0.12)" }}>
      <CropImageDialog
        open={cropOpen}
        file={avatarFile}
        onClose={() => {
          setCropOpen(false);
          setAvatarFile(null);
        }}
        onSave={async (blob) => {
          const file = new File([blob], "avatar.png", { type: "image/png" });
          const formData = new FormData();
          formData.append("file", file);
          setUploadingAvatar(true);
          try {
            const response = await api.post<{ avatarImageDataUrl?: string }>("/auth/avatar", formData, {
              headers: { "Content-Type": "multipart/form-data" },
            });
            setMe((prev) => (prev ? { ...prev, avatarImageDataUrl: response.data?.avatarImageDataUrl ?? prev.avatarImageDataUrl } : prev));
            setCropOpen(false);
            setAvatarFile(null);
            toast(t("profileImageUpdated"), "success");
          } catch (e: any) {
            toast(String(e?.response?.data || e?.message || t("profileImageUploadFailed")), "error");
          } finally {
            setUploadingAvatar(false);
          }
        }}
      />

      {loadError ? (
        <Alert severity="error" sx={{ mb: 2, borderRadius: 2.5 }} action={<Button color="inherit" size="small" onClick={() => void loadProfile()}>Retry</Button>}>
          Unable to load profile.
          <Typography variant="body2" sx={{ mt: 0.5 }}>{loadError}</Typography>
        </Alert>
      ) : null}

      <Box sx={{ display: "flex", justifyContent: "space-between", gap: 2, flexWrap: "wrap" }}>
        <Box sx={{ display: "flex", alignItems: "center", gap: 2, flexWrap: "wrap" }}>
          <Box sx={{ display: "flex", flexDirection: "column", alignItems: "center", gap: 1 }}>
            <Avatar src={me?.avatarImageDataUrl || undefined} sx={{ width: 84, height: 84, fontWeight: 900, fontSize: 28 }}>{initials}</Avatar>
            <Box sx={{ display: "flex", gap: 1, flexWrap: "wrap", justifyContent: "center" }}>
              <input
                ref={avatarInputRef}
                type="file"
                accept={AVATAR_UPLOAD_ACCEPT}
                style={{ display: "none" }}
                onChange={(event) => {
                  const file = event.target.files?.[0] ?? null;
                  event.target.value = "";
                  if (!file) return;
                  setAvatarFile(file);
                  setCropOpen(true);
                }}
              />
              <Button variant="outlined" size="small" startIcon={<PhotoCameraOutlinedIcon />} disabled={!isLocal || uploadingAvatar} onClick={() => avatarInputRef.current?.click()}>
                {uploadingAvatar ? t("profileUploading") : t("profileChangeImage")}
              </Button>
              {me?.avatarImageDataUrl ? (
                <Button
                  variant="text"
                  size="small"
                  color="inherit"
                  startIcon={<DeleteOutlineIcon />}
                  disabled={!isLocal || uploadingAvatar}
                  onClick={async () => {
                    setUploadingAvatar(true);
                    try {
                      await api.delete("/auth/avatar");
                      setMe((prev) => (prev ? { ...prev, avatarImageDataUrl: undefined } : prev));
                      toast(t("profileImageRemoved"), "success");
                    } catch (e: any) {
                      toast(String(e?.response?.data || e?.message || t("profileImageRemoveFailed")), "error");
                    } finally {
                      setUploadingAvatar(false);
                    }
                  }}
                >
                  {t("profileRemoveImage")}
                </Button>
              ) : null}
            </Box>
          </Box>
          <Box>
            <Typography variant="h5" sx={{ fontWeight: 900 }}>
              {careerOnly ? "Master career profile" : t("profileTitle")}
            </Typography>
            <Typography sx={{ color: "text.secondary" }}>{me?.userName || me?.displayName || fullName || me?.email || "-"}</Typography>
            <Typography variant="body2" sx={{ color: "text.secondary" }}>{headline || t("profileHeadlinePlaceholder")}</Typography>
          </Box>
        </Box>
        <Box sx={{ display: "flex", gap: 1, flexWrap: "wrap", alignItems: "flex-start" }}>
          <Chip label={providerLabel} color={me?.provider === "local" ? "primary" : "default"} />
          <Chip label={googleLabel} color={me?.googleLink?.linked ? "success" : "default"} variant={me?.googleLink?.linked ? "filled" : "outlined"} />
          <Chip label={cvLabel} color={profileCvText.trim() ? "success" : "warning"} variant={profileCvText.trim() ? "filled" : "outlined"} />
        </Box>
      </Box>

      {!careerOnly ? <>
        <AuthStatusCard />
        <GoogleAuthCard />
        <MicrosoftAuthCard />
      </> : null}

      <Box sx={{ mt: 3, display: "grid", gridTemplateColumns: { xs: "1fr", md: "1fr 1fr" }, gap: 2 }}>
        {!careerOnly ? <Box sx={{ gridColumn: "1 / -1" }}>
          <Typography variant="h6">{t("profileAccountSection")}</Typography>
          {!isLocal ? (
            <Alert severity="info" sx={{ mt: 1 }}>
              {t("profileReadOnlyInfo")}
            </Alert>
          ) : null}
        </Box> : null}

        {!careerOnly ? <>
          <TextField label={t("profileDisplayName")} value={displayName} onChange={(e) => setDisplayName(e.target.value)} disabled={!isLocal} fullWidth />
          <TextField label={t("profileUsername")} value={userName} onChange={(e) => setUserName(e.target.value)} disabled={!isLocal} fullWidth />
          <TextField label={t("profileFirstName")} value={firstName} onChange={(e) => setFirstName(e.target.value)} disabled={!isLocal} fullWidth />
          <TextField label={t("profileLastName")} value={lastName} onChange={(e) => setLastName(e.target.value)} disabled={!isLocal} fullWidth />
          <TextField label={t("profileNewEmail")} value={email} onChange={(e) => setEmail(e.target.value)} disabled={!isLocal} helperText={t("profileCurrentEmail", { email: me?.email || "-" })} fullWidth />
          <TextField
          label={t("profileHeadline")}
          value={headline}
          onChange={(e) => setHeadline(e.target.value)}
          helperText={t("profileHeadlineHelp")}
          fullWidth
          />
        </> : null}

        {!careerOnly && isLocal ? <Box sx={{ gridColumn: "1 / -1", display: "grid", gridTemplateColumns: { xs: "1fr", md: "1fr auto auto" }, gap: 2, alignItems: "center" }}>
          {pendingEmail ? <Alert severity="info" sx={{ gridColumn: "1 / -1" }}>{t("profilePendingEmail", { email: pendingEmail })}</Alert> : null}
          <TextField label={t("profileEmailChangePassword")} type="password" value={emailChangePassword} onChange={(e) => setEmailChangePassword(e.target.value)} autoComplete="current-password" fullWidth />
          <Button
            variant="outlined"
            disabled={loading || !emailChangePassword || !email.trim() || email.trim().toLowerCase() === (me?.email || "").toLowerCase()}
            onClick={async () => {
              setLoading(true);
              try {
                const result = await api.post<PendingEmailChange>("/auth/email-change/request", { email, currentPassword: emailChangePassword });
                setPendingEmail(result.data?.pendingEmail ?? email.trim());
                setEmailChangePassword("");
                toast(t("profileEmailChangeSent"), "success");
              } catch (e: any) {
                toast(getApiErrorMessage(e, t("profileEmailChangeFailed")), "error");
              } finally {
                setLoading(false);
              }
            }}
          >
            {t("profileRequestEmailChange")}
          </Button>
          <Button
            disabled={loading || !pendingEmail || !emailChangePassword}
            onClick={async () => {
              setLoading(true);
              try {
                await api.post("/auth/email-change/cancel", { currentPassword: emailChangePassword });
                setPendingEmail(null);
                setEmail(me?.email ?? "");
                setEmailChangePassword("");
                toast(t("profileEmailChangeCancelled"), "success");
              } catch (e: any) {
                toast(getApiErrorMessage(e, t("profileEmailChangeFailed")), "error");
              } finally {
                setLoading(false);
              }
            }}
          >
            {t("cancel")}
          </Button>
        </Box> : null}


        <Box sx={{ gridColumn: "1 / -1", display: "flex", justifyContent: "flex-end", gap: 2, flexWrap: "wrap", alignItems: "center" }}>
          <Button
            variant="contained"
            disabled={!isLocal || loading}
            onClick={async () => {
              setLoading(true);
              try {
                // /profile saves identity only. The backend does partial updates, so omitting the
                // master-profile fields leaves them untouched (they are owned by /career).
                await api.put("/auth/profile", { userName, firstName, lastName, displayName });
                const userKey = me?.id || me?.email || me?.userName;
                if (userKey) window.localStorage.setItem(getUserScopedStorageKey("profileHeadline", userKey), headline.trim());
                await loadProfile();
                toast(t("profileUpdated"), "success");
              } catch (e: any) {
                const msg = e?.response?.data || e?.message || t("profileUpdateFailed");
                toast(String(msg), "error");
              } finally {
                setLoading(false);
              }
            }}
          >
            {t("profileSaveChanges")}
          </Button>
        </Box>

        {!careerOnly ? <Box sx={{ gridColumn: "1 / -1", mt: 1 }}>
          <Divider sx={{ mb: 2 }} />
          <Typography variant="h6">{t("profileChangePassword")}</Typography>
          {!isLocal ? <Typography sx={{ color: "text.secondary" }}>{t("profilePasswordLocalOnly")}</Typography> : null}
        </Box> : null}

        {!careerOnly ? <>
          <TextField label={t("profileCurrentPassword")} type="password" value={currentPassword} onChange={(e) => setCurrentPassword(e.target.value)} disabled={!isLocal} fullWidth />
          <TextField label={t("profileNewPassword")} type="password" value={newPassword} onChange={(e) => setNewPassword(e.target.value)} disabled={!isLocal} fullWidth />

          <Box sx={{ gridColumn: "1 / -1", display: "flex", justifyContent: "flex-end" }}>
          <Button
            variant="outlined"
            disabled={!isLocal || loading}
            onClick={async () => {
              setLoading(true);
              try {
                await api.post("/auth/change-password", { currentPassword, newPassword });
                setCurrentPassword("");
                setNewPassword("");
                toast(t("profilePasswordUpdated"), "success");
              } catch (e: any) {
                const msg = e?.response?.data || e?.message || t("profilePasswordUpdateFailed");
                toast(String(msg), "error");
              } finally {
                setLoading(false);
              }
            }}
          >
            {t("profileUpdatePassword")}
          </Button>
          </Box>
        </> : null}
      </Box>

      {!careerOnly && isLocal ? <TwoFactorSettingsCard /> : null}
      {!careerOnly && isLocal ? <SessionsSettingsCard /> : null}
    </Paper>
  );
}
