import { createFileRoute } from "@tanstack/react-router";
import { useEffect, useState } from "react";
import { supabase } from "@/integrations/supabase/client";
import { useAuth, type AppRole } from "@/lib/auth";
import { ProtectedLayout } from "@/components/protected-layout";
import { PageContainer, PageHeader } from "@/components/app-shell";
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 {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
  DialogTrigger,
} from "@/components/ui/dialog";
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle,
  AlertDialogTrigger,
} from "@/components/ui/alert-dialog";
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select";
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "@/components/ui/table";
import { Badge } from "@/components/ui/badge";
import { Loader2, UserPlus, Trash2, KeyRound, Briefcase, Search } from "lucide-react";
import { Checkbox } from "@/components/ui/checkbox";
import { toast } from "sonner";

export const Route = createFileRoute("/admin/users")({
  component: () => (
    <ProtectedLayout adminOnly>
      <UsersPage />
    </ProtectedLayout>
  ),
});

interface UserRow {
  id: string;
  email: string;
  full_name: string;
  created_at: string;
  hourly_rate: number | null;
  title: string | null;
  role: AppRole | null;
}

const ROLE_LABEL: Record<AppRole, string> = {
  admin: "Administrator",
  attorney: "Attorney",
  paralegal: "Paralegal",
  legal_clerk: "Legal Clerk",
  staff: "Staff",
};

const TITLE_OPTIONS = [
  "Attorney",
  "Paralegal",
  "Legal Assistant",
  "Admin",
  "Other",
] as const;
type UserTitle = (typeof TITLE_OPTIONS)[number];

function UsersPage() {
  const { user: currentUser } = useAuth();
  const [users, setUsers] = useState<UserRow[]>([]);
  const [loading, setLoading] = useState(true);
  const [inviteOpen, setInviteOpen] = useState(false);
  const [search, setSearch] = useState("");
  const [titleFilter, setTitleFilter] = useState<string>("all");

  const load = async () => {
    setLoading(true);
    const [{ data: profiles }, { data: rolesData }] = await Promise.all([
      supabase.from("profiles").select("id, email, full_name, created_at, hourly_rate, title"),
      supabase.from("user_roles").select("user_id, role"),
    ]);
    const roleMap = new Map<string, AppRole>();
    (rolesData ?? []).forEach((r) => roleMap.set(r.user_id, r.role as AppRole));
    const rows: UserRow[] = (profiles ?? []).map((p: any) => ({
      id: p.id,
      email: p.email,
      full_name: p.full_name,
      created_at: p.created_at,
      hourly_rate: p.hourly_rate,
      title: p.title ?? null,
      role: roleMap.get(p.id) ?? null,
    }));
    rows.sort((a, b) => a.email.localeCompare(b.email));
    setUsers(rows);
    setLoading(false);
  };

  useEffect(() => {
    load();
  }, []);

  const handleRoleChange = async (userId: string, role: AppRole) => {
    const { error } = await supabase.functions.invoke("admin-update-role", {
      body: { user_id: userId, role },
    });
    if (error) {
      toast.error("Could not update role", { description: error.message });
      return;
    }
    toast.success("Role updated");
    load();
  };

  const handleDelete = async (userId: string) => {
    const { error } = await supabase.functions.invoke("admin-delete-user", {
      body: { user_id: userId },
    });
    if (error) {
      toast.error("Could not delete user", { description: error.message });
      return;
    }
    toast.success("User deleted");
    load();
  };

  const handleRateSave = async (userId: string, rate: number | null) => {
    const { error } = await supabase
      .from("profiles")
      .update({ hourly_rate: rate })
      .eq("id", userId);
    if (error) {
      toast.error("Could not save rate", { description: error.message });
      return;
    }
    toast.success("Rate updated");
    load();
  };

  const handleTitleChange = async (userId: string, title: string | null) => {
    const { error } = await supabase
      .from("profiles")
      .update({ title })
      .eq("id", userId);
    if (error) {
      toast.error("Could not update title", { description: error.message });
      return;
    }
    toast.success("Title updated");
    load();
  };

  const filteredUsers = users.filter((u) => {
    if (titleFilter !== "all") {
      if (titleFilter === "__none__" ? u.title : u.title !== titleFilter) return false;
    }
    const q = search.trim().toLowerCase();
    if (!q) return true;
    return (
      u.email.toLowerCase().includes(q) ||
      (u.full_name ?? "").toLowerCase().includes(q) ||
      (u.title ?? "").toLowerCase().includes(q)
    );
  });

  const titleCounts = TITLE_OPTIONS.reduce<Record<string, number>>((acc, t) => {
    acc[t] = users.filter((u) => u.title === t).length;
    return acc;
  }, {});
  const noTitleCount = users.filter((u) => !u.title).length;

  return (
    <PageContainer>
      <PageHeader
        title="Users"
        description="Invite team members and manage their access."
        actions={
          <Dialog open={inviteOpen} onOpenChange={setInviteOpen}>
            <DialogTrigger asChild>
              <Button>
                <UserPlus className="h-4 w-4 mr-2" />
                Invite user
              </Button>
            </DialogTrigger>
            <InviteDialog
              onCreated={() => {
                setInviteOpen(false);
                load();
              }}
            />
          </Dialog>
        }
      />

      <Card>
        <CardHeader>
          <CardTitle className="font-serif">Team members</CardTitle>
          <CardDescription>
            {filteredUsers.length} of {users.length} shown
          </CardDescription>
        </CardHeader>
        <CardContent>
          <div className="flex flex-col sm:flex-row gap-2 mb-4">
            <div className="relative flex-1">
              <Search className="absolute left-2 top-1/2 -translate-y-1/2 h-4 w-4 text-muted-foreground" />
              <Input
                value={search}
                onChange={(e) => setSearch(e.target.value)}
                placeholder="Search by name, email, or title"
                className="pl-8"
              />
            </div>
            <Select value={titleFilter} onValueChange={setTitleFilter}>
              <SelectTrigger className="w-full sm:w-[220px]">
                <SelectValue placeholder="Filter by title" />
              </SelectTrigger>
              <SelectContent>
                <SelectItem value="all">All titles ({users.length})</SelectItem>
                <SelectItem value="__none__">No title ({noTitleCount})</SelectItem>
                {TITLE_OPTIONS.map((t) => (
                  <SelectItem key={t} value={t}>
                    {t} ({titleCounts[t] ?? 0})
                  </SelectItem>
                ))}
              </SelectContent>
            </Select>
          </div>
          {loading ? (
            <div className="flex items-center justify-center py-12">
              <Loader2 className="h-5 w-5 animate-spin text-muted-foreground" />
            </div>
          ) : filteredUsers.length === 0 ? (
            <div className="text-sm text-muted-foreground py-8 text-center">No users yet.</div>
          ) : (
            <Table>
              <TableHeader>
                <TableRow>
                  <TableHead>Name</TableHead>
                  <TableHead>Email</TableHead>
                  <TableHead className="w-[170px]">Title</TableHead>
                  <TableHead>Role</TableHead>
                  <TableHead className="w-[140px]">Hourly rate</TableHead>
                  <TableHead className="w-[120px] text-right">Actions</TableHead>
                </TableRow>
              </TableHeader>
              <TableBody>
                {filteredUsers.map((u) => {
                  const isSelf = u.id === currentUser?.id;
                  return (
                    <TableRow key={u.id}>
                      <TableCell className="font-medium">
                        {u.full_name || <span className="text-muted-foreground">—</span>}
                        {isSelf && (
                          <Badge variant="secondary" className="ml-2">
                            You
                          </Badge>
                        )}
                      </TableCell>
                      <TableCell className="text-muted-foreground">{u.email}</TableCell>
                      <TableCell>
                        <Select
                          value={u.title ?? "__none__"}
                          onValueChange={(v) =>
                            handleTitleChange(u.id, v === "__none__" ? null : v)
                          }
                        >
                          <SelectTrigger className="w-[160px]">
                            <SelectValue placeholder="No title" />
                          </SelectTrigger>
                          <SelectContent>
                            <SelectItem value="__none__">No title</SelectItem>
                            {TITLE_OPTIONS.map((t) => (
                              <SelectItem key={t} value={t}>
                                {t}
                              </SelectItem>
                            ))}
                          </SelectContent>
                        </Select>
                      </TableCell>
                      <TableCell>
                        <Select
                          value={u.role ?? undefined}
                          onValueChange={(v) => handleRoleChange(u.id, v as AppRole)}
                          disabled={isSelf}
                        >
                          <SelectTrigger className="w-[160px]">
                            <SelectValue placeholder="No role" />
                          </SelectTrigger>
                          <SelectContent>
                            {(Object.keys(ROLE_LABEL) as AppRole[]).map((r) => (
                              <SelectItem key={r} value={r}>
                                {ROLE_LABEL[r]}
                              </SelectItem>
                            ))}
                          </SelectContent>
                        </Select>
                      </TableCell>
                      <TableCell>
                        <RateInput
                          value={u.hourly_rate}
                          onSave={(v) => handleRateSave(u.id, v)}
                        />
                      </TableCell>
                      <TableCell>
                        <div className="flex items-center justify-end gap-1">
                          <SetPasswordDialog userId={u.id} email={u.email} />
                          <ManageCasesDialog userId={u.id} userName={u.full_name || u.email} />
                          {!isSelf && (
                            <AlertDialog>
                              <AlertDialogTrigger asChild>
                                <Button variant="ghost" size="icon">
                                  <Trash2 className="h-4 w-4 text-destructive" />
                                </Button>
                              </AlertDialogTrigger>
                              <AlertDialogContent>
                                <AlertDialogHeader>
                                  <AlertDialogTitle>Delete user?</AlertDialogTitle>
                                  <AlertDialogDescription>
                                    This will permanently remove {u.email} and revoke their access.
                                  </AlertDialogDescription>
                                </AlertDialogHeader>
                                <AlertDialogFooter>
                                  <AlertDialogCancel>Cancel</AlertDialogCancel>
                                  <AlertDialogAction onClick={() => handleDelete(u.id)}>
                                    Delete
                                  </AlertDialogAction>
                                </AlertDialogFooter>
                              </AlertDialogContent>
                            </AlertDialog>
                          )}
                        </div>
                      </TableCell>
                    </TableRow>
                  );
                })}
              </TableBody>
            </Table>
          )}
        </CardContent>
      </Card>
    </PageContainer>
  );
}

function RateInput({
  value,
  onSave,
}: {
  value: number | null;
  onSave: (v: number | null) => void | Promise<void>;
}) {
  const [text, setText] = useState(value != null ? String(value) : "");
  useEffect(() => setText(value != null ? String(value) : ""), [value]);
  const dirty = text !== (value != null ? String(value) : "");

  const commit = () => {
    if (!dirty) return;
    if (text.trim() === "") return onSave(null);
    const n = parseFloat(text);
    if (Number.isNaN(n) || n < 0) {
      toast.error("Invalid rate");
      setText(value != null ? String(value) : "");
      return;
    }
    onSave(n);
  };

  return (
    <div className="flex items-center gap-1">
      <span className="text-xs text-muted-foreground">$</span>
      <Input
        type="number"
        step="0.01"
        min="0"
        value={text}
        onChange={(e) => setText(e.target.value)}
        onBlur={commit}
        onKeyDown={(e) => {
          if (e.key === "Enter") (e.target as HTMLInputElement).blur();
        }}
        placeholder="—"
        className="h-8 w-24"
      />
      <span className="text-xs text-muted-foreground">/hr</span>
    </div>
  );
}


function SetPasswordDialog({ userId, email }: { userId: string; email: string }) {
  const [open, setOpen] = useState(false);
  const [password, setPassword] = useState("");
  const [submitting, setSubmitting] = useState(false);

  const onSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    setSubmitting(true);
    const { error } = await supabase.functions.invoke("admin-set-password", {
      body: { user_id: userId, password },
    });
    setSubmitting(false);
    if (error) {
      toast.error("Could not change password", { description: error.message });
      return;
    }
    toast.success("Password updated", {
      description: "Share the new password securely with the user.",
    });
    setPassword("");
    setOpen(false);
  };

  return (
    <Dialog open={open} onOpenChange={setOpen}>
      <DialogTrigger asChild>
        <Button variant="ghost" size="icon" title="Change password">
          <KeyRound className="h-4 w-4" />
        </Button>
      </DialogTrigger>
      <DialogContent>
        <DialogHeader>
          <DialogTitle className="font-serif">Change password</DialogTitle>
          <DialogDescription>
            Set a new password for {email}. Share it with them through a secure channel.
          </DialogDescription>
        </DialogHeader>
        <form onSubmit={onSubmit} className="space-y-4">
          <div className="space-y-2">
            <Label htmlFor="new-password">New password</Label>
            <Input
              id="new-password"
              type="text"
              value={password}
              onChange={(e) => setPassword(e.target.value)}
              minLength={10}
              required
              autoFocus
            />
            <p className="text-xs text-muted-foreground">Min 10 characters.</p>
          </div>
          <DialogFooter>
            <Button type="submit" disabled={submitting}>
              {submitting && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
              Update password
            </Button>
          </DialogFooter>
        </form>
      </DialogContent>
    </Dialog>
  );
}

function InviteDialog({ onCreated }: { onCreated: () => void }) {
  const [email, setEmail] = useState("");
  const [fullName, setFullName] = useState("");
  const [password, setPassword] = useState("");
  const [role, setRole] = useState<AppRole>("attorney");
  const [submitting, setSubmitting] = useState(false);

  const onSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    setSubmitting(true);
    const { error } = await supabase.functions.invoke("admin-invite-user", {
      body: { email: email.trim(), password, full_name: fullName.trim(), role },
    });
    setSubmitting(false);
    if (error) {
      toast.error("Could not create user", { description: error.message });
      return;
    }
    toast.success("User created", {
      description: "Share the temporary password securely with them.",
    });
    setEmail("");
    setFullName("");
    setPassword("");
    setRole("attorney");
    onCreated();
  };

  return (
    <DialogContent>
      <DialogHeader>
        <DialogTitle className="font-serif">Invite user</DialogTitle>
        <DialogDescription>
          Create an account with a temporary password. Share it with them through a secure channel.
        </DialogDescription>
      </DialogHeader>
      <form onSubmit={onSubmit} className="space-y-4">
        <div className="space-y-2">
          <Label htmlFor="invite-name">Full name</Label>
          <Input
            id="invite-name"
            value={fullName}
            onChange={(e) => setFullName(e.target.value)}
            required
          />
        </div>
        <div className="space-y-2">
          <Label htmlFor="invite-email">Email</Label>
          <Input
            id="invite-email"
            type="email"
            value={email}
            onChange={(e) => setEmail(e.target.value)}
            required
          />
        </div>
        <div className="space-y-2">
          <Label htmlFor="invite-password">Temporary password</Label>
          <Input
            id="invite-password"
            type="text"
            value={password}
            onChange={(e) => setPassword(e.target.value)}
            minLength={10}
            required
          />
          <p className="text-xs text-muted-foreground">
            Min 10 characters. The user can change it after first sign-in.
          </p>
        </div>
        <div className="space-y-2">
          <Label>Role</Label>
          <Select value={role} onValueChange={(v) => setRole(v as AppRole)}>
            <SelectTrigger>
              <SelectValue />
            </SelectTrigger>
            <SelectContent>
              {(Object.keys(ROLE_LABEL) as AppRole[]).map((r) => (
                <SelectItem key={r} value={r}>
                  {ROLE_LABEL[r]}
                </SelectItem>
              ))}
            </SelectContent>
          </Select>
        </div>
        <DialogFooter>
          <Button type="submit" disabled={submitting}>
            {submitting && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
            Create user
          </Button>
        </DialogFooter>
      </form>
    </DialogContent>
  );
}

interface CaseOption {
  id: string;
  case_number: string;
  title: string;
  status: string;
  client_name: string | null;
}

function ManageCasesDialog({ userId, userName }: { userId: string; userName: string }) {
  const [open, setOpen] = useState(false);
  const [loading, setLoading] = useState(false);
  const [submitting, setSubmitting] = useState(false);
  const [cases, setCases] = useState<CaseOption[]>([]);
  const [initial, setInitial] = useState<Set<string>>(new Set());
  const [selected, setSelected] = useState<Set<string>>(new Set());
  const [primary, setPrimary] = useState<Set<string>>(new Set());
  const [search, setSearch] = useState("");
  const [onlyMine, setOnlyMine] = useState(false);

  const load = async () => {
    setLoading(true);
    const [{ data: caseRows }, { data: teamRows }] = await Promise.all([
      supabase
        .from("cases")
        .select("id, case_number, title, status, assigned_attorney_id, originating_attorney_id, clients(name)")
        .is("archived_at", null)
        .order("case_number", { ascending: false })
        .limit(1000),
      supabase.from("case_team_members").select("case_id").eq("user_id", userId),
    ]);
    const opts: CaseOption[] = (caseRows ?? []).map((c: any) => ({
      id: c.id,
      case_number: c.case_number,
      title: c.title,
      status: c.status,
      client_name: c.clients?.name ?? null,
    }));
    const prim = new Set<string>(
      (caseRows ?? [])
        .filter((c: any) => c.assigned_attorney_id === userId || c.originating_attorney_id === userId)
        .map((c: any) => c.id),
    );
    const team = new Set<string>((teamRows ?? []).map((r: any) => r.case_id));
    const all = new Set<string>([...prim, ...team]);
    setCases(opts);
    setPrimary(prim);
    setInitial(team);
    setSelected(new Set(all));
    setLoading(false);
  };

  useEffect(() => {
    if (open) load();
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [open]);

  const toggle = (id: string, checked: boolean) => {
    setSelected((prev) => {
      const next = new Set(prev);
      if (checked) next.add(id);
      else next.delete(id);
      return next;
    });
  };

  const filtered = cases.filter((c) => {
    if (onlyMine && !selected.has(c.id)) return false;
    if (!search.trim()) return true;
    const q = search.toLowerCase();
    return (
      c.case_number.toLowerCase().includes(q) ||
      c.title.toLowerCase().includes(q) ||
      (c.client_name ?? "").toLowerCase().includes(q)
    );
  });

  const visibleIds = filtered.map((c) => c.id);
  const allVisibleSelected = visibleIds.length > 0 && visibleIds.every((id) => selected.has(id));
  const toggleAllVisible = (checked: boolean) => {
    setSelected((prev) => {
      const next = new Set(prev);
      visibleIds.forEach((id) => {
        if (checked) next.add(id);
        else if (!primary.has(id)) next.delete(id);
      });
      return next;
    });
  };

  const onSave = async () => {
    setSubmitting(true);
    // Diff against the team-membership set only (primary attorney rows aren't editable here)
    const target = new Set<string>([...selected].filter((id) => !primary.has(id)));
    const toAdd = [...target].filter((id) => !initial.has(id));
    const toRemove = [...initial].filter((id) => !target.has(id));

    try {
      if (toAdd.length > 0) {
        const { error } = await supabase
          .from("case_team_members")
          .insert(toAdd.map((case_id) => ({ case_id, user_id: userId })));
        if (error) throw error;
      }
      if (toRemove.length > 0) {
        const { error } = await supabase
          .from("case_team_members")
          .delete()
          .eq("user_id", userId)
          .in("case_id", toRemove);
        if (error) throw error;
      }
      toast.success("Case assignments updated", {
        description: `${toAdd.length} added, ${toRemove.length} removed`,
      });
      setOpen(false);
    } catch (e: any) {
      toast.error("Could not update assignments", { description: e.message });
    } finally {
      setSubmitting(false);
    }
  };

  return (
    <Dialog open={open} onOpenChange={setOpen}>
      <DialogTrigger asChild>
        <Button variant="ghost" size="icon" title="Manage case assignments">
          <Briefcase className="h-4 w-4" />
        </Button>
      </DialogTrigger>
      <DialogContent className="max-w-2xl">
        <DialogHeader>
          <DialogTitle className="font-serif">Assign cases</DialogTitle>
          <DialogDescription>
            Add or remove {userName} from case teams. Primary attorney assignments are shown but managed on the case itself.
          </DialogDescription>
        </DialogHeader>

        <div className="flex items-center gap-2">
          <div className="relative flex-1">
            <Search className="absolute left-2.5 top-2.5 h-4 w-4 text-muted-foreground" />
            <Input
              value={search}
              onChange={(e) => setSearch(e.target.value)}
              placeholder="Search by case number, title, or client"
              className="pl-8"
            />
          </div>
          <label className="flex items-center gap-2 text-sm whitespace-nowrap">
            <Checkbox checked={onlyMine} onCheckedChange={(v) => setOnlyMine(!!v)} />
            Assigned only
          </label>
        </div>

        <div className="border rounded-md max-h-[420px] overflow-auto">
          {loading ? (
            <div className="flex items-center justify-center py-12">
              <Loader2 className="h-5 w-5 animate-spin text-muted-foreground" />
            </div>
          ) : filtered.length === 0 ? (
            <div className="text-sm text-muted-foreground py-8 text-center">No cases match.</div>
          ) : (
            <Table>
              <TableHeader className="sticky top-0 bg-background">
                <TableRow>
                  <TableHead className="w-10">
                    <Checkbox
                      checked={allVisibleSelected}
                      onCheckedChange={(v) => toggleAllVisible(!!v)}
                      aria-label="Select all visible"
                    />
                  </TableHead>
                  <TableHead>Case</TableHead>
                  <TableHead>Client</TableHead>
                  <TableHead className="w-24">Status</TableHead>
                </TableRow>
              </TableHeader>
              <TableBody>
                {filtered.map((c) => {
                  const isPrimary = primary.has(c.id);
                  const isChecked = selected.has(c.id);
                  return (
                    <TableRow key={c.id}>
                      <TableCell>
                        <Checkbox
                          checked={isChecked}
                          disabled={isPrimary}
                          onCheckedChange={(v) => toggle(c.id, !!v)}
                        />
                      </TableCell>
                      <TableCell>
                        <div className="font-medium">{c.case_number}</div>
                        <div className="text-xs text-muted-foreground line-clamp-1">{c.title}</div>
                        {isPrimary && (
                          <Badge variant="secondary" className="mt-1">
                            Primary attorney
                          </Badge>
                        )}
                      </TableCell>
                      <TableCell className="text-muted-foreground text-sm">
                        {c.client_name ?? "—"}
                      </TableCell>
                      <TableCell className="text-xs text-muted-foreground capitalize">
                        {c.status}
                      </TableCell>
                    </TableRow>
                  );
                })}
              </TableBody>
            </Table>
          )}
        </div>

        <DialogFooter className="flex items-center justify-between sm:justify-between">
          <div className="text-xs text-muted-foreground">
            {selected.size} assigned · {cases.length} total
          </div>
          <Button onClick={onSave} disabled={submitting || loading}>
            {submitting && <Loader2 className="mr-2 h-4 w-4 animate-spin" />}
            Save assignments
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  );
}