"use client";

import type { ReactElement, SyntheticEvent } from "react";

import { useCallback, useEffect, useState } from "react";
import Link from "next/link";
import { createTeam, fetchTeams, type CreateTeamDto, type TeamRecord } from "@/lib/api/teams";

function getErrorMessage(error: unknown, fallback: string): string {
  if (error instanceof Error) {
    return error.message;
  }

  return fallback;
}

export default function TeamsSettingsPage(): ReactElement {
  const [teams, setTeams] = useState<TeamRecord[]>([]);
  const [isLoading, setIsLoading] = useState(true);
  const [loadError, setLoadError] = useState<string | null>(null);
  const [isCreateDialogOpen, setIsCreateDialogOpen] = useState(false);
  const [isCreating, setIsCreating] = useState(false);
  const [newTeamName, setNewTeamName] = useState("");
  const [newTeamDescription, setNewTeamDescription] = useState("");
  const [createError, setCreateError] = useState<string | null>(null);

  const loadTeams = useCallback(async (): Promise<void> => {
    setIsLoading(true);

    try {
      const data = await fetchTeams();
      setTeams(data);
      setLoadError(null);
    } catch (error) {
      setLoadError(getErrorMessage(error, "Failed to load teams"));
    } finally {
      setIsLoading(false);
    }
  }, []);

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

  const handleCreateTeam = async (e: SyntheticEvent<HTMLFormElement>): Promise<void> => {
    e.preventDefault();

    const teamName = newTeamName.trim();
    if (!teamName) return;

    setIsCreating(true);
    setCreateError(null);

    try {
      const description = newTeamDescription.trim();
      const dto: CreateTeamDto = { name: teamName };
      if (description.length > 0) {
        dto.description = description;
      }

      await createTeam(dto);
      setNewTeamName("");
      setNewTeamDescription("");
      setIsCreateDialogOpen(false);
      await loadTeams();
    } catch (error) {
      setCreateError(getErrorMessage(error, "Failed to create team"));
    } finally {
      setIsCreating(false);
    }
  };

  return (
    <main className="container mx-auto px-4 py-8 max-w-5xl">
      <div className="mb-8">
        <div className="flex items-center justify-between mb-2">
          <h1 className="text-3xl font-bold text-gray-900">Teams</h1>
          <Link href="/settings" className="text-sm text-blue-600 hover:text-blue-700">
            {"<-"} Back to Settings
          </Link>
        </div>
        <p className="text-gray-600">Manage teams in your active workspace</p>
      </div>

      <div className="bg-white rounded-lg shadow-sm border border-gray-200 p-6 mb-6">
        <div className="flex items-center justify-between gap-4">
          <div>
            <h2 className="text-lg font-semibold text-gray-900">Create New Team</h2>
            <p className="text-sm text-gray-600 mt-1">
              Add a team to organize members and permissions.
            </p>
          </div>
          <button
            type="button"
            onClick={() => {
              setCreateError(null);
              setIsCreateDialogOpen(true);
            }}
            className="px-6 py-2 bg-blue-600 text-white rounded-lg hover:bg-blue-700 font-medium"
          >
            Create Team
          </button>
        </div>
      </div>

      {isCreateDialogOpen && (
        <div
          className="fixed inset-0 z-50 flex items-center justify-center bg-black/40 px-4"
          role="dialog"
        >
          <div className="w-full max-w-lg rounded-lg border border-gray-200 bg-white p-6 shadow-xl">
            <h3 className="text-lg font-semibold text-gray-900">Create New Team</h3>
            <p className="mt-1 text-sm text-gray-600">
              Enter a team name and optional description.
            </p>

            <form onSubmit={handleCreateTeam} className="mt-4 space-y-4">
              <div>
                <label htmlFor="team-name" className="mb-1 block text-sm font-medium text-gray-700">
                  Team Name
                </label>
                <input
                  id="team-name"
                  type="text"
                  value={newTeamName}
                  onChange={(e) => {
                    setNewTeamName(e.target.value);
                  }}
                  placeholder="Enter team name..."
                  disabled={isCreating}
                  className="w-full rounded-lg border border-gray-300 px-4 py-2 focus:border-transparent focus:ring-2 focus:ring-blue-500 disabled:bg-gray-100"
                  autoFocus
                />
              </div>

              <div>
                <label
                  htmlFor="team-description"
                  className="mb-1 block text-sm font-medium text-gray-700"
                >
                  Description (optional)
                </label>
                <textarea
                  id="team-description"
                  value={newTeamDescription}
                  onChange={(e) => {
                    setNewTeamDescription(e.target.value);
                  }}
                  placeholder="Describe this team's purpose..."
                  disabled={isCreating}
                  rows={3}
                  className="w-full rounded-lg border border-gray-300 px-4 py-2 focus:border-transparent focus:ring-2 focus:ring-blue-500 disabled:bg-gray-100"
                />
              </div>

              {createError !== null && (
                <div className="rounded-md border border-red-200 bg-red-50 px-3 py-2 text-sm text-red-700">
                  {createError}
                </div>
              )}

              <div className="flex justify-end gap-3">
                <button
                  type="button"
                  onClick={() => {
                    if (!isCreating) {
                      setIsCreateDialogOpen(false);
                    }
                  }}
                  disabled={isCreating}
                  className="px-4 py-2 rounded-lg border border-gray-300 text-gray-700 hover:bg-gray-50 disabled:cursor-not-allowed"
                >
                  Cancel
                </button>
                <button
                  type="submit"
                  disabled={isCreating || !newTeamName.trim()}
                  className="px-5 py-2 rounded-lg bg-blue-600 text-white font-medium hover:bg-blue-700 disabled:cursor-not-allowed disabled:opacity-50"
                >
                  {isCreating ? "Creating..." : "Create Team"}
                </button>
              </div>
            </form>
          </div>
        </div>
      )}

      <div className="space-y-4">
        <h2 className="text-xl font-semibold text-gray-900">
          Your Teams ({isLoading ? "..." : teams.length})
        </h2>
        {loadError !== null ? (
          <div className="rounded-md border border-red-200 bg-red-50 px-4 py-3 text-red-700">
            {loadError}
          </div>
        ) : isLoading ? (
          <div className="bg-white rounded-lg shadow-sm border border-gray-200 p-12 text-center text-gray-600">
            Loading teams...
          </div>
        ) : teams.length === 0 ? (
          <div className="bg-white rounded-lg shadow-sm border border-gray-200 p-12 text-center">
            <svg
              className="mx-auto h-12 w-12 text-gray-400 mb-4"
              fill="none"
              stroke="currentColor"
              viewBox="0 0 24 24"
            >
              <path
                strokeLinecap="round"
                strokeLinejoin="round"
                strokeWidth={2}
                d="M17 20h5V8H2v12h5m10 0v-4a3 3 0 10-6 0v4m6 0H7"
              />
            </svg>
            <h3 className="text-lg font-medium text-gray-900 mb-2">No teams yet</h3>
            <p className="text-gray-600">Create your first team to get started</p>
          </div>
        ) : (
          <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
            {teams.map((team) => (
              <article
                key={team.id}
                className="rounded-lg border border-gray-200 bg-white p-5 shadow-sm"
                data-testid="team-card"
              >
                <h3 className="text-lg font-semibold text-gray-900">{team.name}</h3>
                {team.description ? (
                  <p className="mt-1 text-sm text-gray-600">{team.description}</p>
                ) : (
                  <p className="mt-1 text-sm text-gray-400 italic">No description</p>
                )}
                <div className="mt-4 flex items-center gap-3 text-xs text-gray-500">
                  <span>{team._count?.members ?? 0} members</span>
                  <span>|</span>
                  <span>Created {new Date(team.createdAt).toLocaleDateString()}</span>
                </div>
              </article>
            ))}
          </div>
        )}
      </div>
    </main>
  );
}