import { useState } from "react";

import { Link } from "react-router-dom";

import {
  createProject,
  deleteProject,
  listProjects,
  updateProject,
  type ProjectCreateInput,
  type ProjectUpdateInput,
} from "../api/projects";
import { EmptyState, ErrorState, LoadingState } from "../components/data-states";
import { Icon } from "../components/icon";
import { useAsyncData } from "../hooks/use-async-data";
import type { Project } from "../types";

type DialogMode = "none" | "create" | "edit";

export const ProjectsPage = () => {
  const { data: projects, status, reload } = useAsyncData<Project[]>(listProjects, []);
  const [dialogMode, setDialogMode] = useState<DialogMode>("none");
  const [editingProject, setEditingProject] = useState<Project | null>(null);
  const [formName, setFormName] = useState("");
  const [formDescription, setFormDescription] = useState("");
  const [formError, setFormError] = useState<string | null>(null);
  const [deleteConfirmId, setDeleteConfirmId] = useState<string | null>(null);

  const safeProjects = projects ?? [];

  const openCreate = () => {
    setFormName("");
    setFormDescription("");
    setFormError(null);
    setEditingProject(null);
    setDialogMode("create");
  };

  const openEdit = (project: Project) => {
    setFormName(project.name);
    setFormDescription(project.description ?? "");
    setFormError(null);
    setEditingProject(project);
    setDialogMode("edit");
  };

  const closeDialog = () => {
    setDialogMode("none");
    setEditingProject(null);
    setFormError(null);
  };

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    setFormError(null);

    if (!formName.trim()) {
      setFormError("Project name is required");
      return;
    }

    try {
      if (dialogMode === "create") {
        const input: ProjectCreateInput = {
          name: formName.trim(),
          description: formDescription.trim() || null,
        };
        await createProject(input);
      } else if (dialogMode === "edit" && editingProject) {
        const input: ProjectUpdateInput = {
          name: formName.trim(),
          description: formDescription.trim() || null,
        };
        await updateProject(editingProject.id, input);
      }
      closeDialog();
      reload();
    } catch {
      setFormError("Failed to save project");
    }
  };

  const handleDelete = async (projectId: string) => {
    try {
      await deleteProject(projectId);
      setDeleteConfirmId(null);
      reload();
    } catch {
      setDeleteConfirmId(null);
    }
  };

  const isEmpty = status === "ready" && safeProjects.length === 0;

  return (
    <section className="stack">
      <div className="page-header">
        <h1>Projects</h1>
        <button className="primary-button" onClick={openCreate} type="button">
          <Icon name="add" size="sm" />
          New Project
        </button>
      </div>

      {status === "loading" && <LoadingState message="Loading projects..." />}

      {status === "error" && <ErrorState message="Failed to load projects" onRetry={reload} />}

      {isEmpty && <EmptyState message="No projects yet. Create your first project above." />}

      {status === "ready" && safeProjects.length > 0 && (
        <div className="project-list">
          {safeProjects.map((project) => (
            <article className="card project-card" key={project.id}>
              <div className="project-info">
                <h3>{project.name}</h3>
                {project.description && <p className="muted">{project.description}</p>}
              </div>
              <div className="project-actions">
                <Link className="ghost-button" to={`/projects/${project.id}`}>
                  Open Workspace
                </Link>
                <button
                  className="ghost-button"
                  onClick={() => openEdit(project)}
                  type="button"
                >
                  <Icon name="edit" size="sm" />
                  Edit
                </button>
                {deleteConfirmId === project.id ? (
                  <div className="delete-confirm">
                    <span>Are you sure?</span>
                    <button
                      className="danger-button"
                      onClick={() => void handleDelete(project.id)}
                      type="button"
                    >
                      <Icon name="delete" size="sm" />
                      Delete
                    </button>
                    <button
                      className="ghost-button"
                      onClick={() => setDeleteConfirmId(null)}
                      type="button"
                    >
                      <Icon name="cancel" size="sm" />
                      Cancel
                    </button>
                  </div>
                ) : (
                  <button
                    className="ghost-button danger-text"
                    onClick={() => setDeleteConfirmId(project.id)}
                    type="button"
                  >
                    <Icon name="delete" size="sm" />
                    Delete
                  </button>
                )}
              </div>
            </article>
          ))}
        </div>
      )}

      {dialogMode !== "none" && (
        <div className="dialog-overlay" role="dialog" aria-modal="true">
          <div className="dialog">
            <h2>{dialogMode === "create" ? "Create Project" : "Edit Project"}</h2>
            <form onSubmit={handleSubmit} className="stack">
              <label className="form-field">
                Name
                <input
                  type="text"
                  value={formName}
                  onChange={(e) => setFormName(e.target.value)}
                  placeholder="Project name"
                />
              </label>
              <label className="form-field">
                Description
                <textarea
                  value={formDescription}
                  onChange={(e) => setFormDescription(e.target.value)}
                  placeholder="Optional description"
                  rows={3}
                />
              </label>
              {formError && <p className="error-text">{formError}</p>}
              <div className="dialog-actions">
                <button className="secondary-button" onClick={closeDialog} type="button">
                  <Icon name="cancel" size="sm" />
                  Cancel
                </button>
                <button className="primary-button" type="submit">
                  {dialogMode === "create" ? (
                    <>
                      <Icon name="add" size="sm" />
                      Create
                    </>
                  ) : (
                    <>
                      <Icon name="save" size="sm" />
                      Save
                    </>
                  )}
                </button>
              </div>
            </form>
          </div>
        </div>
      )}
    </section>
  );
};