/**
 * Projects List Page
 *
 * Displays all projects with filtering, sorting, and search.
 * Supports grid and list view modes.
 *
 * @see Issue #54
 */

'use client';

import { useState, useCallback, useMemo } from 'react';
import { useRouter } from '@/lib/i18n/routing';
import { toast } from 'sonner';
import { Plus } from 'lucide-react';
import { Button } from '@/components/ui/button';
import { Link } from '@/lib/i18n/routing';
import { ProjectFilters, ProjectsGrid } from '@/components/projects';
import type { ViewMode, SortBy, SortOrder, Complexity } from '@/components/projects';
import type { ProjectStatus } from '@/components/projects/types';
import { useProjects, type ProjectListItem } from '@/lib/api/hooks/useProjects';
import { useDebounce } from '@/lib/hooks/useDebounce';

export default function ProjectsPage() {
  const router = useRouter();

  // Filter state
  const [searchQuery, setSearchQuery] = useState('');
  const [statusFilter, setStatusFilter] = useState<ProjectStatus | 'all'>('all');
  const [complexityFilter, setComplexityFilter] = useState<Complexity>('all');
  const [sortBy, setSortBy] = useState<SortBy>('recent');
  const [sortOrder, setSortOrder] = useState<SortOrder>('desc');
  const [viewMode, setViewMode] = useState<ViewMode>('grid');

  // Debounce search for API calls
  const debouncedSearch = useDebounce(searchQuery, 300);

  // Fetch projects
  const { data, isLoading, error } = useProjects({
    search: debouncedSearch || undefined,
    status: statusFilter,
    complexity: complexityFilter !== 'all' ? complexityFilter : undefined,
    sortBy,
    sortOrder,
    page: 1,
    limit: 50,
  });

  // Check if any filters are active (for empty state message)
  const hasFilters = useMemo(() => {
    return searchQuery !== '' || statusFilter !== 'all' || complexityFilter !== 'all';
  }, [searchQuery, statusFilter, complexityFilter]);

  // Handle project card click
  const handleProjectClick = useCallback(
    (project: ProjectListItem) => {
      router.push(`/projects/${project.id}`);
    },
    [router]
  );

  // Handle project action
  const handleProjectAction = useCallback(
    (project: ProjectListItem, action: 'archive' | 'pause' | 'resume' | 'delete') => {
      // TODO: Implement actual API calls
      switch (action) {
        case 'archive':
          toast.success(`Archived: ${project.name}`);
          break;
        case 'pause':
          toast.info(`Paused: ${project.name}`);
          break;
        case 'resume':
          toast.success(`Resumed: ${project.name}`);
          break;
        case 'delete':
          toast.error(`Deleted: ${project.name}`);
          break;
      }
    },
    []
  );

  // Show error toast if fetch fails
  if (error) {
    toast.error('Failed to load projects', {
      description: 'Please try again later',
    });
  }

  return (
    <div className="container mx-auto px-4 py-6">
      {/* Header */}
      <div className="mb-6 flex flex-col gap-4 sm:flex-row sm:items-center sm:justify-between">
        <div>
          <h1 className="text-3xl font-bold">Projects</h1>
          <p className="text-muted-foreground">Manage and monitor your projects</p>
        </div>
        <Button asChild>
          <Link href="/projects/new">
            <Plus className="mr-2 h-4 w-4" />
            Create Project
          </Link>
        </Button>
      </div>

      {/* Filters */}
      <ProjectFilters
        searchQuery={searchQuery}
        onSearchChange={setSearchQuery}
        statusFilter={statusFilter}
        onStatusFilterChange={setStatusFilter}
        complexityFilter={complexityFilter}
        onComplexityFilterChange={setComplexityFilter}
        sortBy={sortBy}
        onSortByChange={setSortBy}
        sortOrder={sortOrder}
        onSortOrderChange={setSortOrder}
        viewMode={viewMode}
        onViewModeChange={setViewMode}
        className="mb-6"
      />

      {/* Projects Grid */}
      <ProjectsGrid
        projects={data?.data ?? []}
        isLoading={isLoading}
        viewMode={viewMode}
        onProjectClick={handleProjectClick}
        onProjectAction={handleProjectAction}
        hasFilters={hasFilters}
      />

      {/* Pagination - TODO: Add when more than 50 projects */}
      {data && data.pagination.totalPages > 1 && (
        <div className="mt-6 flex items-center justify-between text-sm text-muted-foreground">
          <span>
            Showing {data.data.length} of {data.pagination.total} projects
          </span>
          {/* TODO: Add pagination controls */}
        </div>
      )}
    </div>
  );
}