import { useCallback, useEffect, useMemo, useState } from "react";
import { useTranslation } from "react-i18next";
import { toast } from "sonner";
import {
  ArrowLeft,
  Check,
  ListChecks,
  Search,
  Share2,
  Shield,
  User,
  Users,
  X,
} from "lucide-react";
import { Button } from "@/components/button";
import { Input } from "@/components/input";
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuTrigger,
} from "@/components/dropdown-menu";
import { Select2 } from "@/components/select2";
import {
  getCredentialAccess,
  getRoles,
  revokeCredentialAccess,
  shareCredential,
  type CredentialPermissionLevel,
  type ShareTarget,
} from "@/api/rbac-api";
import { getUserList, type AccessRecord } from "@/main-axios";
import type { Credential } from "@/types/ui-types";
import { getErrorMessage } from "@/lib/error-message";

const PERMISSION_LEVELS: CredentialPermissionLevel[] = ["use", "manage"];

const LEVEL_KEYS: Record<
  CredentialPermissionLevel,
  { label: string; description: string }
> = {
  use: {
    label: "credentials.share.levelUse",
    description: "credentials.share.levelUseDesc",
  },
  manage: {
    label: "credentials.share.levelManage",
    description: "credentials.share.levelManageDesc",
  },
};

const EXPIRY_PRESETS = [
  { key: "never", hours: null },
  { key: "oneHour", hours: 1 },
  { key: "oneDay", hours: 24 },
  { key: "sevenDays", hours: 24 * 7 },
  { key: "thirtyDays", hours: 24 * 30 },
  { key: "custom", hours: undefined },
] as const;

type ExpiryPresetKey = (typeof EXPIRY_PRESETS)[number]["key"];

function levelOf(record: AccessRecord): CredentialPermissionLevel {
  return record.permissionLevel === "manage" ? "manage" : "use";
}

export function CredentialShareModal({
  credential,
  onClose,
}: {
  credential: Credential | null;
  onClose: () => void;
}) {
  const { t } = useTranslation();
  const [targetTab, setTargetTab] = useState<"user" | "role">("user");
  const [search, setSearch] = useState("");
  const [shareUsers, setShareUsers] = useState<
    { id: string; username: string }[]
  >([]);
  const [shareRoles, setShareRoles] = useState<
    { id: number; name: string; displayName?: string }[]
  >([]);
  const [selectedUserIds, setSelectedUserIds] = useState<Set<string>>(
    new Set(),
  );
  const [selectedRoleIds, setSelectedRoleIds] = useState<Set<number>>(
    new Set(),
  );
  const [permissionLevel, setPermissionLevel] =
    useState<CredentialPermissionLevel>("use");
  const [expiryPreset, setExpiryPreset] = useState<ExpiryPresetKey>("never");
  const [customHours, setCustomHours] = useState("");
  const [accessList, setAccessList] = useState<AccessRecord[]>([]);
  const [loadError, setLoadError] = useState(false);
  const [submitting, setSubmitting] = useState(false);

  const credentialId = credential ? Number(credential.id) : null;

  const refreshAccessList = useCallback(async () => {
    if (!credentialId) return;
    setAccessList((await getCredentialAccess(credentialId)).access ?? []);
  }, [credentialId]);

  useEffect(() => {
    setSearch("");
    setSelectedUserIds(new Set());
    setSelectedRoleIds(new Set());
    setPermissionLevel("use");
    setExpiryPreset("never");
    setCustomHours("");
    setTargetTab("user");
    setAccessList([]);
    setLoadError(false);
    if (!credentialId) return;

    Promise.all([
      getCredentialAccess(credentialId).catch(() => ({ access: [] })),
      getUserList().catch(() => ({ users: [] })),
      getRoles().catch(() => ({ roles: [] })),
    ])
      .then(([accessRes, usersRes, rolesRes]) => {
        setAccessList(accessRes.access ?? []);
        setShareUsers(
          (usersRes.users ?? []).map((u) => ({
            id: String(u.userId),
            username: u.username,
          })),
        );
        setShareRoles(
          (rolesRes.roles ?? [])
            .filter((r) => !r.isSystem)
            .map((r) => ({
              id: Number(r.id),
              name: r.name,
              displayName: r.displayName,
            })),
        );
      })
      .catch(() => setLoadError(true));
  }, [credentialId]);

  const filteredUsers = useMemo(() => {
    const q = search.trim().toLowerCase();
    return q
      ? shareUsers.filter((u) => u.username.toLowerCase().includes(q))
      : shareUsers;
  }, [shareUsers, search]);

  const filteredRoles = useMemo(() => {
    const q = search.trim().toLowerCase();
    return q
      ? shareRoles.filter(
          (r) =>
            r.name.toLowerCase().includes(q) ||
            (r.displayName ?? "").toLowerCase().includes(q),
        )
      : shareRoles;
  }, [shareRoles, search]);

  const selectedCount = selectedUserIds.size + selectedRoleIds.size;

  const durationHours = (() => {
    if (expiryPreset === "never") return undefined;
    if (expiryPreset === "custom") {
      const hours = Number(customHours);
      return Number.isFinite(hours) && hours > 0 ? hours : undefined;
    }
    return (
      EXPIRY_PRESETS.find((p) => p.key === expiryPreset)?.hours ?? undefined
    );
  })();

  async function handleShare() {
    if (!credentialId || selectedCount === 0) return;
    const targets: ShareTarget[] = [
      ...Array.from(selectedUserIds, (id) => ({ type: "user" as const, id })),
      ...Array.from(selectedRoleIds, (id) => ({ type: "role" as const, id })),
    ];
    setSubmitting(true);
    try {
      await shareCredential(
        credentialId,
        targets,
        permissionLevel,
        durationHours,
      );
      await refreshAccessList();
      setSelectedUserIds(new Set());
      setSelectedRoleIds(new Set());
      toast.success(t("credentials.share.shared"));
    } catch (e) {
      toast.error(getErrorMessage(e));
    } finally {
      setSubmitting(false);
    }
  }

  // No update route for credential grants, so re-share with the time left.
  async function handleLevelChange(
    record: AccessRecord,
    level: CredentialPermissionLevel,
  ) {
    if (!credentialId || levelOf(record) === level) return;
    const target: ShareTarget | null =
      record.targetType === "role" && record.roleId != null
        ? { type: "role", id: Number(record.roleId) }
        : record.userId
          ? { type: "user", id: String(record.userId) }
          : null;
    if (!target) return;
    let remainingHours: number | undefined;
    if (record.expiresAt) {
      remainingHours =
        (new Date(record.expiresAt).getTime() - Date.now()) / 3_600_000;
      if (remainingHours <= 0) {
        toast.error(t("hosts.sharing.accessUpdateFailed"));
        return;
      }
    }
    try {
      await shareCredential(credentialId, [target], level, remainingHours);
      await refreshAccessList();
      toast.success(t("hosts.sharing.accessUpdated"));
    } catch {
      toast.error(t("hosts.sharing.accessUpdateFailed"));
    }
  }

  async function handleRevoke(record: AccessRecord) {
    if (!credentialId) return;
    try {
      await revokeCredentialAccess(credentialId, record.id);
      setAccessList((prev) => prev.filter((entry) => entry.id !== record.id));
      toast.success(t("credentials.share.accessRevoked"));
    } catch (e) {
      toast.error(getErrorMessage(e));
    }
  }

  if (!credential) return null;

  return (
    <div className="absolute inset-0 z-20 flex flex-col bg-sidebar">
      <button
        onClick={onClose}
        className="flex items-center gap-2 px-3 py-2 shrink-0 border-b border-border text-xs text-muted-foreground hover:text-foreground transition-colors w-full text-left"
      >
        <ArrowLeft className="size-3.5 shrink-0" />
        <span className="truncate">
          {t("credentials.share.title", { name: credential.name ?? "" })}
        </span>
      </button>

      {loadError && (
        <div className="flex items-start gap-2 px-3 py-2 shrink-0 border-b border-destructive/30 bg-destructive/5 text-xs text-destructive">
          <Shield className="size-3.5 shrink-0 mt-0.5" />
          <div>{t("hosts.sharing.loadError")}</div>
        </div>
      )}

      <div className="flex flex-col gap-2 p-3 shrink-0 border-b border-border">
        <div className="flex items-center justify-between gap-2">
          <div className="flex items-center gap-1.5 text-[10px] font-semibold uppercase tracking-widest text-muted-foreground">
            <Users className="size-3.5" />
            {t("hosts.sharing.shareWithSection")}
          </div>
          <a
            href="https://docs.termix.site/features/authentication/rbac"
            target="_blank"
            rel="noreferrer"
            className="text-[10px] text-accent-brand hover:underline shrink-0"
          >
            {t("hosts.docsLink")}
          </a>
        </div>

        <p className="text-[11px] text-muted-foreground leading-snug">
          {t("credentials.share.description")}
        </p>

        <div className="flex gap-1.5">
          {(["user", "role"] as const).map((tab) => (
            <button
              key={tab}
              onClick={() => setTargetTab(tab)}
              className={`flex-1 flex items-center justify-center gap-1 px-2 py-1.5 text-[10px] font-bold uppercase tracking-widest border transition-colors ${targetTab === tab ? "border-accent-brand/40 bg-accent-brand/10 text-accent-brand" : "border-border text-muted-foreground hover:text-foreground"}`}
            >
              {tab === "user" ? (
                <User className="size-3 shrink-0" />
              ) : (
                <Shield className="size-3 shrink-0" />
              )}
              {tab === "user"
                ? t("hosts.sharing.usersTab")
                : t("hosts.sharing.rolesTab")}
              {tab === "user" && selectedUserIds.size > 0 && (
                <span>({selectedUserIds.size})</span>
              )}
              {tab === "role" && selectedRoleIds.size > 0 && (
                <span>({selectedRoleIds.size})</span>
              )}
            </button>
          ))}
        </div>

        <div className="relative">
          <Search className="absolute left-2.5 top-1/2 -translate-y-1/2 size-3.5 text-muted-foreground/50" />
          <Input
            placeholder={t("hosts.sharing.searchPlaceholder")}
            value={search}
            onChange={(e) => setSearch(e.target.value)}
            className="pl-8"
          />
        </div>

        <div className="flex flex-col border border-border h-28 overflow-y-auto">
          {targetTab === "user" &&
            (filteredUsers.length === 0 ? (
              <div className="px-3 py-4 text-xs text-muted-foreground/50 text-center">
                {t("hosts.sharing.noMatches")}
              </div>
            ) : (
              filteredUsers.map((user) => {
                const isSelected = selectedUserIds.has(user.id);
                return (
                  <button
                    key={user.id}
                    onClick={() =>
                      setSelectedUserIds((prev) => {
                        const next = new Set(prev);
                        if (next.has(user.id)) next.delete(user.id);
                        else next.add(user.id);
                        return next;
                      })
                    }
                    className={`flex items-center gap-2 px-2.5 py-1.5 text-xs text-left border-b border-border/50 last:border-0 transition-colors shrink-0 ${isSelected ? "bg-accent-brand/10 text-accent-brand" : "hover:bg-muted/40"}`}
                  >
                    <div
                      className={`size-3.5 border flex items-center justify-center shrink-0 transition-colors ${isSelected ? "border-accent-brand bg-accent-brand" : "border-border bg-background"}`}
                    >
                      {isSelected && (
                        <Check className="size-2.5 text-background" />
                      )}
                    </div>
                    <User className="size-3 text-muted-foreground shrink-0" />
                    <span className="truncate">{user.username}</span>
                  </button>
                );
              })
            ))}
          {targetTab === "role" &&
            (filteredRoles.length === 0 ? (
              <div className="px-3 py-4 text-xs text-muted-foreground/50 text-center">
                {t("hosts.sharing.noMatches")}
              </div>
            ) : (
              filteredRoles.map((role) => {
                const isSelected = selectedRoleIds.has(role.id);
                return (
                  <button
                    key={role.id}
                    onClick={() =>
                      setSelectedRoleIds((prev) => {
                        const next = new Set(prev);
                        if (next.has(role.id)) next.delete(role.id);
                        else next.add(role.id);
                        return next;
                      })
                    }
                    className={`flex items-center gap-2 px-2.5 py-1.5 text-xs text-left border-b border-border/50 last:border-0 transition-colors shrink-0 ${isSelected ? "bg-accent-brand/10 text-accent-brand" : "hover:bg-muted/40"}`}
                  >
                    <div
                      className={`size-3.5 border flex items-center justify-center shrink-0 transition-colors ${isSelected ? "border-accent-brand bg-accent-brand" : "border-border bg-background"}`}
                    >
                      {isSelected && (
                        <Check className="size-2.5 text-background" />
                      )}
                    </div>
                    <Shield className="size-3 text-muted-foreground shrink-0" />
                    <span className="truncate">
                      {role.displayName || role.name}
                    </span>
                  </button>
                );
              })
            ))}
        </div>

        <div className="flex items-end gap-2">
          <div className="flex flex-col gap-1 flex-1 min-w-0">
            <span className="text-[10px] font-semibold uppercase tracking-widest text-muted-foreground">
              {t("hosts.sharing.permissionLevelLabel")}
            </span>
            <Select2
              value={permissionLevel}
              onChange={(e) =>
                setPermissionLevel(e.target.value as CredentialPermissionLevel)
              }
              className="h-8 w-full px-2.5 text-xs border border-border bg-background hover:bg-muted/40 transition-colors"
            >
              {PERMISSION_LEVELS.map((level) => (
                <option key={level} value={level}>
                  {t(LEVEL_KEYS[level].label)}
                </option>
              ))}
            </Select2>
          </div>

          <DropdownMenu>
            <DropdownMenuTrigger asChild>
              <button className="flex flex-col gap-1 shrink-0">
                <span className="text-[10px] font-semibold uppercase tracking-widest text-muted-foreground text-left">
                  {t("hosts.sharing.expiryLabel")}
                </span>
                <span className="h-8 flex items-center justify-center px-2.5 text-xs border border-border hover:bg-muted/40 transition-colors whitespace-nowrap">
                  {t(`hosts.sharing.expiry.${expiryPreset}`)}
                </span>
              </button>
            </DropdownMenuTrigger>
            <DropdownMenuContent align="end" className="text-xs">
              {EXPIRY_PRESETS.map((preset) => (
                <DropdownMenuItem
                  key={preset.key}
                  onClick={() => setExpiryPreset(preset.key)}
                >
                  {expiryPreset === preset.key ? (
                    <Check className="size-3 mr-1.5" />
                  ) : (
                    <span className="size-3 mr-1.5" />
                  )}
                  {t(`hosts.sharing.expiry.${preset.key}`)}
                </DropdownMenuItem>
              ))}
            </DropdownMenuContent>
          </DropdownMenu>

          <Button
            variant="outline"
            className="h-8 shrink-0 border-accent-brand/40 text-accent-brand hover:bg-accent-brand/10 hover:text-accent-brand"
            disabled={
              selectedCount === 0 ||
              submitting ||
              (expiryPreset === "custom" && !durationHours)
            }
            onClick={handleShare}
          >
            <Share2 className="size-3.5 mr-1.5" />
            {selectedCount > 0
              ? t("hosts.sharing.shareWithCount", { count: selectedCount })
              : t("hosts.sharing.shareButton")}
          </Button>
        </div>

        <p className="text-[11px] text-muted-foreground leading-snug">
          {t(LEVEL_KEYS[permissionLevel].description)}
        </p>

        {expiryPreset === "custom" && (
          <Input
            type="number"
            autoFocus
            placeholder={t("hosts.sharing.customHoursPlaceholder")}
            value={customHours}
            onChange={(e) => setCustomHours(e.target.value)}
            className="[appearance:textfield] [&::-webkit-outer-spin-button]:appearance-none [&::-webkit-inner-spin-button]:appearance-none"
          />
        )}
      </div>

      <div className="flex flex-col flex-1 min-h-0">
        <div className="flex items-center gap-1.5 px-3 py-2 shrink-0 border-b border-border text-[10px] font-semibold uppercase tracking-widest text-muted-foreground">
          <ListChecks className="size-3.5" />
          {t("hosts.sharing.currentAccess")}
          {accessList.length > 0 && (
            <span className="text-muted-foreground/40">
              ({accessList.length})
            </span>
          )}
        </div>
        <div className="flex-1 min-h-0 overflow-y-auto">
          {accessList.length === 0 && (
            <div className="px-3 py-6 text-xs text-muted-foreground/50 text-center">
              {t("credentials.share.noAccessEntries")}
            </div>
          )}
          {accessList.map((record) => {
            const expired =
              record.expiresAt && new Date(record.expiresAt) < new Date();
            const recordLevel = levelOf(record);
            return (
              <div
                key={record.id}
                className="flex flex-col gap-1 px-3 py-2 border-b border-border/60 last:border-0 text-xs"
              >
                <div className="flex items-center justify-between gap-2">
                  <div className="flex items-center gap-1.5 min-w-0">
                    {record.targetType === "user" ? (
                      <User className="size-3 text-muted-foreground shrink-0" />
                    ) : (
                      <Shield className="size-3 text-muted-foreground shrink-0" />
                    )}
                    <span className="font-semibold truncate">
                      {record.username ??
                        record.roleDisplayName ??
                        record.roleName ??
                        record.userId ??
                        record.roleId}
                    </span>
                  </div>
                  <div className="flex items-center gap-1 shrink-0">
                    <DropdownMenu>
                      <DropdownMenuTrigger asChild>
                        <button className="px-1.5 py-0.5 text-[9px] font-bold uppercase tracking-widest border border-accent-brand/30 bg-accent-brand/10 text-accent-brand transition-colors hover:bg-accent-brand/20">
                          {t(LEVEL_KEYS[recordLevel].label)}
                        </button>
                      </DropdownMenuTrigger>
                      <DropdownMenuContent align="end" className="text-xs">
                        {PERMISSION_LEVELS.map((level) => (
                          <DropdownMenuItem
                            key={level}
                            onClick={() => handleLevelChange(record, level)}
                          >
                            {recordLevel === level ? (
                              <Check className="size-3 mr-1.5" />
                            ) : (
                              <span className="size-3 mr-1.5" />
                            )}
                            {t(LEVEL_KEYS[level].label)}
                          </DropdownMenuItem>
                        ))}
                      </DropdownMenuContent>
                    </DropdownMenu>
                    <Button
                      variant="ghost"
                      size="sm"
                      className="h-6 text-[10px] px-2 text-destructive hover:bg-destructive/10"
                      onClick={() => void handleRevoke(record)}
                    >
                      {t("hosts.sharing.revoke")}
                    </Button>
                  </div>
                </div>
                <div className="flex items-center gap-3 text-[10px] text-muted-foreground pl-4">
                  <span>
                    {t("hosts.sharing.grantedBy")}:{" "}
                    <span className="text-foreground/70">
                      {record.grantedByUsername ?? "?"}
                    </span>
                  </span>
                  <span className={expired ? "text-destructive" : ""}>
                    {t("hosts.sharing.expires")}:{" "}
                    {expired ? (
                      <span className="inline-flex items-center gap-0.5 text-destructive">
                        <X className="size-3" />
                        {t("hosts.sharing.expired")}
                      </span>
                    ) : record.expiresAt ? (
                      <span className="text-foreground/70">
                        {new Date(record.expiresAt).toLocaleString()}
                      </span>
                    ) : (
                      <span className="text-foreground/70">
                        {t("hosts.sharing.never")}
                      </span>
                    )}
                  </span>
                </div>
              </div>
            );
          })}
        </div>
      </div>
    </div>
  );
}