import { useState, useEffect } from 'react';
import type { ReactElement } from 'react';
import { Layout } from '@/components/layout/Layout';
import {
  StatusBadge,
  ViewModuleModal,
  DataTable,
  Pagination,
  FilterDropdown,
  type Column,
} from '@/components/shared';
import { Download, ArrowUpDown } from 'lucide-react';
import { moduleService } from '@/services/module-service';
import type { Module } from '@/types/module';

// Helper function to format date
const formatDate = (dateString: string): string => {
  const date = new Date(dateString);
  return date.toLocaleDateString('en-US', { month: 'short', day: 'numeric', year: 'numeric' });
};

// Helper function to get status badge variant
const getStatusVariant = (status: string | null): 'success' | 'failure' | 'process' => {
  if (!status) return 'process';
  switch (status.toLowerCase()) {
    case 'running':
    case 'active':
    case 'healthy':
      return 'success';
    case 'stopped':
    case 'failed':
    case 'unhealthy':
      return 'failure';
    default:
      return 'process';
  }
};

const Modules = (): ReactElement => {
  const [modules, setModules] = useState<Module[]>([]);
  const [isLoading, setIsLoading] = useState<boolean>(true);
  const [error, setError] = useState<string | null>(null);

  // Pagination state
  const [currentPage, setCurrentPage] = useState<number>(1);
  const [limit, setLimit] = useState<number>(5);
  const [pagination, setPagination] = useState<{
    page: number;
    limit: number;
    total: number;
    totalPages: number;
    hasMore: boolean;
  }>({
    page: 1,
    limit: 5,
    total: 0,
    totalPages: 1,
    hasMore: false,
  });

  // Filter state
  const [statusFilter, setStatusFilter] = useState<string | null>(null);
  const [orderBy, setOrderBy] = useState<string[] | null>(null);

  // View modal
  const [viewModalOpen, setViewModalOpen] = useState<boolean>(false);
  const [selectedModuleId, setSelectedModuleId] = useState<string | null>(null);

  const fetchModules = async (
    page: number,
    itemsPerPage: number,
    status: string | null = null,
    sortBy: string[] | null = null
  ): Promise<void> => {
    try {
      setIsLoading(true);
      setError(null);
      const response = await moduleService.getAll(page, itemsPerPage, status, sortBy);
      if (response.success) {
        setModules(response.data);
        setPagination(response.pagination);
      } else {
        setError('Failed to load modules');
      }
    } catch (err: any) {
      setError(err?.response?.data?.error?.message || 'Failed to load modules');
    } finally {
      setIsLoading(false);
    }
  };

  // Fetch modules on mount and when pagination/filters change
  useEffect(() => {
    fetchModules(currentPage, limit, statusFilter, orderBy);
  }, [currentPage, limit, statusFilter, orderBy]);

  // View module handler
  const handleViewModule = (moduleId: string): void => {
    setSelectedModuleId(moduleId);
    setViewModalOpen(true);
  };

  // Load module for view
  const loadModule = async (id: string): Promise<Module> => {
    const response = await moduleService.getById(id);
    return response.data;
  };

  // Define table columns
  const columns: Column<Module>[] = [
    {
      key: 'name',
      label: 'Module Name',
      render: (module) => (
        <div className="flex items-center gap-3">
          <div className="w-8 h-8 bg-[#f5f7fa] border border-[rgba(0,0,0,0.08)] rounded-lg flex items-center justify-center shrink-0">
            <span className="text-xs font-normal text-[#9aa6b2]">
              {module.name.substring(0, 2).toUpperCase()}
            </span>
          </div>
          <div className="flex flex-col">
            <span className="text-sm font-normal text-[#0f1724]">{module.name}</span>
            <span className="text-xs text-[#6b7280] font-mono">{module.module_id}</span>
          </div>
        </div>
      ),
      mobileLabel: 'Name',
    },
    {
      key: 'description',
      label: 'Description',
      render: (module) => (
        <span className="text-sm font-normal text-[#0f1724] line-clamp-1">{module.description}</span>
      ),
    },
    {
      key: 'version',
      label: 'Version',
      render: (module) => (
        <span className="text-sm font-normal text-[#0f1724]">{module.version}</span>
      ),
    },
    {
      key: 'status',
      label: 'Status',
      render: (module) => (
        <StatusBadge variant={getStatusVariant(module.status)}>
          {module.status || 'Unknown'}
        </StatusBadge>
      ),
    },
    {
      key: 'health_status',
      label: 'Health Status',
      render: (module) => (
        <StatusBadge variant={getStatusVariant(module.health_status)}>
          {module.health_status || 'N/A'}
        </StatusBadge>
      ),
    },
    {
      key: 'runtime_language',
      label: 'Runtime',
      render: (module) => (
        <span className="text-sm font-normal text-[#0f1724]">
          {module.runtime_language || 'N/A'}
        </span>
      ),
    },
    {
      key: 'created_at',
      label: 'Registered Date',
      render: (module) => (
        <span className="text-sm font-normal text-[#6b7280]">{formatDate(module.created_at)}</span>
      ),
      mobileLabel: 'Registered',
    },
    {
      key: 'actions',
      label: 'Actions',
      align: 'right',
      render: (module) => (
        <div className="flex justify-end">
          <button
            type="button"
            onClick={() => handleViewModule(module.id)}
            className="text-sm text-[#112868] hover:text-[#0d1f4e] font-medium transition-colors"
          >
            View
          </button>
        </div>
      ),
    },
  ];

  // Mobile card renderer
  const mobileCardRenderer = (module: Module) => (
    <div className="p-4">
      <div className="flex items-start justify-between gap-3 mb-3">
        <div className="flex items-center gap-3 flex-1 min-w-0">
          <div className="w-8 h-8 bg-[#f5f7fa] border border-[rgba(0,0,0,0.08)] rounded-lg flex items-center justify-center shrink-0">
            <span className="text-xs font-normal text-[#9aa6b2]">
              {module.name.substring(0, 2).toUpperCase()}
            </span>
          </div>
          <div className="flex-1 min-w-0">
            <h3 className="text-sm font-medium text-[#0f1724] truncate">{module.name}</h3>
            <p className="text-xs text-[#6b7280] mt-0.5 truncate font-mono">{module.module_id}</p>
          </div>
        </div>
        <button
          type="button"
          onClick={() => handleViewModule(module.id)}
          className="text-sm text-[#112868] hover:text-[#0d1f4e] font-medium transition-colors shrink-0"
        >
          View
        </button>
      </div>
      <div className="grid grid-cols-2 gap-3 text-xs">
        <div>
          <span className="text-[#9aa6b2]">Status:</span>
          <div className="mt-1">
            <StatusBadge variant={getStatusVariant(module.status)}>
              {module.status || 'Unknown'}
            </StatusBadge>
          </div>
        </div>
        <div>
          <span className="text-[#9aa6b2]">Health:</span>
          <div className="mt-1">
            <StatusBadge variant={getStatusVariant(module.health_status)}>
              {module.health_status || 'N/A'}
            </StatusBadge>
          </div>
        </div>
        <div>
          <span className="text-[#9aa6b2]">Version:</span>
          <p className="text-[#0f1724] font-normal mt-1">{module.version}</p>
        </div>
        <div>
          <span className="text-[#9aa6b2]">Runtime:</span>
          <p className="text-[#0f1724] font-normal mt-1">{module.runtime_language || 'N/A'}</p>
        </div>
        <div>
          <span className="text-[#9aa6b2]">Registered:</span>
          <p className="text-[#6b7280] font-normal mt-1">{formatDate(module.created_at)}</p>
        </div>
        <div>
          <span className="text-[#9aa6b2]">Description:</span>
          <p className="text-[#0f1724] font-normal mt-1 line-clamp-2">{module.description}</p>
        </div>
      </div>
    </div>
  );

  return (
    <Layout
      currentPage="Modules"
      pageHeader={{
        title: 'Module List',
        description: 'View and manage all system modules registered in the QAssure platform.',
      }}
    >
      {/* Table Container */}
      <div className="bg-white border border-[rgba(0,0,0,0.08)] rounded-lg shadow-[0px_4px_24px_0px_rgba(0,0,0,0.02)] overflow-hidden">
        {/* Table Header with Filters */}
        <div className="border-b border-[rgba(0,0,0,0.08)] px-4 md:px-5 py-3 flex flex-col sm:flex-row items-start sm:items-center justify-between gap-3">
          {/* Filters */}
          <div className="flex flex-wrap items-center gap-3">
            {/* Status Filter */}
            <FilterDropdown
              label="Status"
              options={[
                { value: 'running', label: 'Running' },
                { value: 'stopped', label: 'Stopped' },
                { value: 'failed', label: 'Failed' },
              ]}
              value={statusFilter}
              onChange={(value) => {
                setStatusFilter(value as string | null);
                setCurrentPage(1);
              }}
              placeholder="All"
            />

            {/* Sort Filter */}
            <FilterDropdown
              label="Sort by"
              options={[
                { value: ['name', 'asc'], label: 'Name (A-Z)' },
                { value: ['name', 'desc'], label: 'Name (Z-A)' },
                { value: ['module_id', 'asc'], label: 'Module ID (A-Z)' },
                { value: ['module_id', 'desc'], label: 'Module ID (Z-A)' },
                { value: ['status', 'asc'], label: 'Status (A-Z)' },
                { value: ['status', 'desc'], label: 'Status (Z-A)' },
                { value: ['created_at', 'asc'], label: 'Created (Oldest)' },
                { value: ['created_at', 'desc'], label: 'Created (Newest)' },
                { value: ['updated_at', 'asc'], label: 'Updated (Oldest)' },
                { value: ['updated_at', 'desc'], label: 'Updated (Newest)' },
              ]}
              value={orderBy}
              onChange={(value) => {
                setOrderBy(value as string[] | null);
                setCurrentPage(1);
              }}
              placeholder="Default"
              showIcon
              icon={<ArrowUpDown className="w-3.5 h-3.5 text-[#475569]" />}
            />
          </div>

          {/* Actions */}
          <div className="flex items-center gap-2">
            {/* Export Button */}
            <button
              type="button"
              className="flex items-center gap-1.5 px-3 py-2 bg-white border border-[rgba(0,0,0,0.08)] rounded-md text-xs text-[#0f1724] hover:bg-gray-50 transition-colors"
            >
              <Download className="w-3.5 h-3.5" />
              <span>Export</span>
            </button>
          </div>
        </div>

        {/* Table */}
        <DataTable
          columns={columns}
          data={modules}
          keyExtractor={(module) => module.id}
          isLoading={isLoading}
          error={error}
          mobileCardRenderer={mobileCardRenderer}
          emptyMessage="No modules found"
        />

        {/* Pagination */}
        {pagination.total > 0 && (
          <div className="border-t border-[rgba(0,0,0,0.08)] px-4 md:px-5 py-3">
            <Pagination
              currentPage={pagination.page}
              totalPages={pagination.totalPages}
              totalItems={pagination.total}
              limit={limit}
              onPageChange={(page: number) => setCurrentPage(page)}
              onLimitChange={(newLimit: number) => {
                setLimit(newLimit);
                setCurrentPage(1);
              }}
            />
          </div>
        )}
      </div>

      {/* View Module Modal */}
      <ViewModuleModal
        isOpen={viewModalOpen}
        onClose={() => {
          setViewModalOpen(false);
          setSelectedModuleId(null);
        }}
        moduleId={selectedModuleId}
        onLoadModule={loadModule}
      />
    </Layout>
  );
};

export default Modules;