import { useState, useEffect, useCallback } from 'react';
import { Link, useSearchParams, useNavigate } from 'react-router-dom';
import { Project, PaginatedResponse } from '../types';
import { listProjects, createProject } from '../api';
import { Badge } from '../components/Badge';
import { DataTable } from '../components/DataTable';
import { FilterDropdown, FilterOption } from '../components/FilterDropdown';
import { FilterChip, FilterChipGroup } from '../components/FilterChip';
import { Pagination } from '../components/Pagination';
import { useAuth } from '../contexts/AuthContext';
import './Home.css';

// Lock icon SVG component
function LockIcon() {
  return (
    <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round" className="lock-icon">
      <rect x="3" y="11" width="18" height="11" rx="2" ry="2" />
      <path d="M7 11V7a5 5 0 0 1 10 0v4" />
    </svg>
  );
}

const VISIBILITY_OPTIONS: FilterOption[] = [
  { value: '', label: 'All Projects' },
  { value: 'public', label: 'Public Only' },
  { value: 'private', label: 'Private Only' },
];

function Home() {
  const [searchParams, setSearchParams] = useSearchParams();
  const navigate = useNavigate();
  const { user } = useAuth();

  const [projectsData, setProjectsData] = useState<PaginatedResponse<Project> | null>(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [showForm, setShowForm] = useState(false);
  const [newProject, setNewProject] = useState({ name: '', description: '', is_public: true });
  const [creating, setCreating] = useState(false);

  // Get params from URL
  const page = parseInt(searchParams.get('page') || '1', 10);
  const sort = searchParams.get('sort') || 'name';
  const order = (searchParams.get('order') || 'asc') as 'asc' | 'desc';
  const visibility = searchParams.get('visibility') || '';

  const updateParams = useCallback(
    (updates: Record<string, string | undefined>) => {
      const newParams = new URLSearchParams(searchParams);
      Object.entries(updates).forEach(([key, value]) => {
        if (value === undefined || value === '' || (key === 'page' && value === '1')) {
          newParams.delete(key);
        } else {
          newParams.set(key, value);
        }
      });
      setSearchParams(newParams);
    },
    [searchParams, setSearchParams]
  );

  const loadProjects = useCallback(async () => {
    try {
      setLoading(true);
      const data = await listProjects({
        page,
        sort,
        order,
        visibility: visibility as 'public' | 'private' | undefined || undefined,
      });
      setProjectsData(data);
      setError(null);
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Failed to load projects');
    } finally {
      setLoading(false);
    }
  }, [page, sort, order, visibility]);

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

  async function handleCreateProject(e: React.FormEvent) {
    e.preventDefault();
    try {
      setCreating(true);
      await createProject(newProject);
      setNewProject({ name: '', description: '', is_public: true });
      setShowForm(false);
      loadProjects();
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Failed to create project');
    } finally {
      setCreating(false);
    }
  }

  const handleSortChange = (columnKey: string) => {
    // Toggle order if clicking the same column, otherwise default to asc
    const newOrder = columnKey === sort ? (order === 'asc' ? 'desc' : 'asc') : 'asc';
    updateParams({ sort: columnKey, order: newOrder, page: '1' });
  };

  const handleVisibilityChange = (value: string) => {
    updateParams({ visibility: value, page: '1' });
  };

  const handlePageChange = (newPage: number) => {
    updateParams({ page: String(newPage) });
  };

  const clearFilters = () => {
    setSearchParams({});
  };

  const hasActiveFilters = visibility !== '';
  const projects = projectsData?.items || [];
  const pagination = projectsData?.pagination;

  if (loading && !projectsData) {
    return <div className="loading">Loading projects...</div>;
  }

  return (
    <div className="home">
      <div className="page-header">
        <h1>Projects</h1>
        {user ? (
          <button className="btn btn-primary" onClick={() => setShowForm(!showForm)}>
            {showForm ? 'Cancel' : '+ New Project'}
          </button>
        ) : (
          <Link to="/login" className="btn btn-secondary">
            Login to create projects
          </Link>
        )}
      </div>

      {error && <div className="error-message">{error}</div>}

      {showForm && (
        <form className="form card" onSubmit={handleCreateProject}>
          <h3>Create New Project</h3>
          <div className="form-group">
            <label htmlFor="name">Name</label>
            <input
              id="name"
              type="text"
              value={newProject.name}
              onChange={(e) => setNewProject({ ...newProject, name: e.target.value })}
              placeholder="my-project"
              required
            />
          </div>
          <div className="form-group">
            <label htmlFor="description">Description</label>
            <input
              id="description"
              type="text"
              value={newProject.description}
              onChange={(e) => setNewProject({ ...newProject, description: e.target.value })}
              placeholder="Optional description"
            />
          </div>
          <div className="form-group checkbox">
            <label>
              <input
                type="checkbox"
                checked={newProject.is_public}
                onChange={(e) => setNewProject({ ...newProject, is_public: e.target.checked })}
              />
              Public
            </label>
          </div>
          <button type="submit" className="btn btn-primary" disabled={creating}>
            {creating ? 'Creating...' : 'Create Project'}
          </button>
        </form>
      )}

      {user && (
        <div className="list-controls">
          <FilterDropdown
            label="Visibility"
            options={VISIBILITY_OPTIONS}
            value={visibility}
            onChange={handleVisibilityChange}
          />
        </div>
      )}

      {user && hasActiveFilters && (
        <FilterChipGroup onClearAll={clearFilters}>
          {visibility && (
            <FilterChip
              label="Visibility"
              value={visibility === 'public' ? 'Public' : 'Private'}
              onRemove={() => handleVisibilityChange('')}
            />
          )}
        </FilterChipGroup>
      )}

      <div className="data-table--responsive">
        <DataTable
          data={projects}
          keyExtractor={(project) => project.id}
          onRowClick={(project) => navigate(`/project/${project.name}`)}
          onSort={handleSortChange}
          sortKey={sort}
          sortOrder={order}
          emptyMessage={
            hasActiveFilters
              ? 'No projects match your filters. Try adjusting your search.'
              : 'No projects yet. Create your first project to get started!'
          }
          columns={[
            {
              key: 'name',
              header: 'Name',
              sortable: true,
              render: (project) => (
                <span className="cell-name">
                  {!project.is_public && <LockIcon />}
                  {project.name}
                </span>
              ),
            },
            {
              key: 'description',
              header: 'Description',
              className: 'cell-description',
              render: (project) => project.description || '—',
            },
            {
              key: 'visibility',
              header: 'Visibility',
              render: (project) => (
                <Badge variant={project.is_public ? 'public' : 'private'}>
                  {project.is_public ? 'Public' : 'Private'}
                </Badge>
              ),
            },
            {
              key: 'created_by',
              header: 'Owner',
              className: 'cell-owner',
              render: (project) => project.created_by,
            },
            ...(user
              ? [
                  {
                    key: 'access_level',
                    header: 'Access',
                    render: (project: Project) =>
                      project.access_level ? (
                        <Badge
                          variant={
                            project.is_owner
                              ? 'success'
                              : project.access_level === 'admin'
                                ? 'success'
                                : project.access_level === 'write'
                                  ? 'info'
                                  : 'default'
                          }
                        >
                          {project.is_owner
                            ? 'Owner'
                            : project.access_level.charAt(0).toUpperCase() + project.access_level.slice(1)}
                        </Badge>
                      ) : (
                        '—'
                      ),
                  },
                ]
              : []),
            {
              key: 'created_at',
              header: 'Created',
              sortable: true,
              className: 'cell-date',
              render: (project) => new Date(project.created_at).toLocaleDateString(),
            },
            {
              key: 'updated_at',
              header: 'Updated',
              sortable: true,
              className: 'cell-date',
              render: (project) => new Date(project.updated_at).toLocaleDateString(),
            },
          ]}
        />
      </div>

      {pagination && pagination.total_pages > 1 && (
        <Pagination
          page={pagination.page}
          totalPages={pagination.total_pages}
          total={pagination.total}
          limit={pagination.limit}
          onPageChange={handlePageChange}
        />
      )}
    </div>
  );
}

export default Home;