/**
 * Tasks Page - Built with TablePageTemplate
 * Consistent with Keywords page layout, structure and design
 */

import { useState, useEffect, useMemo, useCallback, useRef } from 'react';
import TablePageTemplate from '../../templates/TablePageTemplate';
import {
  fetchTasks,
  createTask,
  updateTask,
  deleteTask,
  bulkDeleteTasks,
  bulkUpdateTasksStatus,
  autoGenerateContent,
  autoGenerateImages,
  Task,
  TasksFilters,
  TaskCreateData,
  fetchClusters,
  Cluster,
} from '../../services/api';
import FormModal from '../../components/common/FormModal';
import ProgressModal from '../../components/common/ProgressModal';
import { useProgressModal } from '../../hooks/useProgressModal';
import { useToast } from '../../components/ui/toast/ToastContainer';
import { TaskIcon, PlusIcon, DownloadIcon, FileIcon, ImageIcon, CheckCircleIcon } from '../../icons';
import { createTasksPageConfig } from '../../config/pages/tasks.config';
import { useSectorStore } from '../../store/sectorStore';
import { usePageSizeStore } from '../../store/pageSizeStore';
import PageHeader from '../../components/common/PageHeader';
import ModuleNavigationTabs from '../../components/navigation/ModuleNavigationTabs';
import ModuleMetricsFooter, { MetricItem, ProgressMetric } from '../../components/dashboard/ModuleMetricsFooter';
import { WorkflowInsight } from '../../components/common/WorkflowInsights';

export default function Tasks() {
  const toast = useToast();
  const { activeSector } = useSectorStore();
  const { pageSize } = usePageSizeStore();

  // Data state
  const [tasks, setTasks] = useState<Task[]>([]);
  const [clusters, setClusters] = useState<Cluster[]>([]);
  const [loading, setLoading] = useState(true);
  
  // Filter state
  const [searchTerm, setSearchTerm] = useState('');
  const [statusFilter, setStatusFilter] = useState('');
  const [clusterFilter, setClusterFilter] = useState('');
  const [structureFilter, setStructureFilter] = useState('');
  const [typeFilter, setTypeFilter] = useState('');
  const [sourceFilter, setSourceFilter] = useState('');
  const [selectedIds, setSelectedIds] = useState<string[]>([]);
  
  // Pagination state
  const [currentPage, setCurrentPage] = useState(1);
  const [totalPages, setTotalPages] = useState(1);
  const [totalCount, setTotalCount] = useState(0);
  
  // Sorting state
  const [sortBy, setSortBy] = useState<string>('created_at');
  const [sortDirection, setSortDirection] = useState<'asc' | 'desc'>('desc');
  const [showContent, setShowContent] = useState(false);
  
  // Modal state
  const [isModalOpen, setIsModalOpen] = useState(false);
  const [isEditMode, setIsEditMode] = useState(false);
  const [editingTask, setEditingTask] = useState<Task | null>(null);
  const [formData, setFormData] = useState<TaskCreateData>({
    title: '',
    description: '',
    keywords: '',
    cluster_id: null,
    content_structure: 'article',
    content_type: 'post',
    status: 'queued',
    word_count: 0,
  });

  // Progress modal for AI functions
  const progressModal = useProgressModal();

  // Calculate workflow insights
  const workflowInsights: WorkflowInsight[] = useMemo(() => {
    const insights: WorkflowInsight[] = [];
    const queuedCount = tasks.filter(t => t.status === 'queued').length;
    const processingCount = tasks.filter(t => t.status === 'in_progress').length;
    const completedCount = tasks.filter(t => t.status === 'completed').length;
    const failedCount = tasks.filter(t => t.status === 'failed').length;
    const completionRate = totalCount > 0 ? Math.round((completedCount / totalCount) * 100) : 0;

    if (totalCount === 0) {
      insights.push({
        type: 'info',
        message: 'No tasks yet - Queue ideas from Planner to start generating content automatically',
      });
      return insights;
    }

    // Queue status
    if (queuedCount > 10) {
      insights.push({
        type: 'warning',
        message: `Large queue detected (${queuedCount} tasks) - Content generation may take time, consider prioritizing`,
      });
    } else if (queuedCount > 0) {
      insights.push({
        type: 'info',
        message: `${queuedCount} tasks in queue - Content generation pipeline is active`,
      });
    }

    // Processing status
    if (processingCount > 0) {
      insights.push({
        type: 'action',
        message: `${processingCount} tasks actively generating content - Check back soon for completed drafts`,
      });
    }

    // Failed tasks
    if (failedCount > 0) {
      insights.push({
        type: 'warning',
        message: `${failedCount} tasks failed - Review errors and retry or adjust task parameters`,
      });
    }

    // Completion success
    if (completionRate >= 70 && completedCount >= 5) {
      insights.push({
        type: 'success',
        message: `High completion rate (${completionRate}%) - ${completedCount} pieces of content ready for review`,
      });
    }

    return insights;
  }, [tasks, totalCount]);

  // AI Function Logs state

  
  const hasReloadedRef = useRef<boolean>(false);



  // Load clusters for filter dropdown
  useEffect(() => {
    const loadClusters = async () => {
      try {
        const data = await fetchClusters({ ordering: 'name' });
        setClusters(data.results || []);
      } catch (error) {
        console.error('Error fetching clusters:', error);
      }
    };
    loadClusters();
  }, []);

  // Load tasks - wrapped in useCallback
  const loadTasks = useCallback(async () => {
    setLoading(true);
    setShowContent(false);
    try {
      const ordering = sortBy ? `${sortDirection === 'desc' ? '-' : ''}${sortBy}` : '-created_at';
      
      // Build search term - combine user search with Site Builder filter if needed
      let finalSearchTerm = searchTerm;
      if (sourceFilter === 'site_builder') {
        // If user has a search term, combine it with Site Builder prefix
        finalSearchTerm = searchTerm ? `[Site Builder] ${searchTerm}` : '[Site Builder]';
      }
      
      const filters: TasksFilters = {
        ...(finalSearchTerm && { search: finalSearchTerm }),
        ...(statusFilter && { status: statusFilter }),
        ...(clusterFilter && { cluster_id: clusterFilter }),
        ...(structureFilter && { content_structure: structureFilter }),
        ...(typeFilter && { content_type: typeFilter }),
        page: currentPage,
        page_size: pageSize,
        ordering,
      };
      
      const data = await fetchTasks(filters);
      setTasks(data.results || []);
      setTotalCount(data.count || 0);
      setTotalPages(Math.ceil((data.count || 0) / pageSize));
      
      setTimeout(() => {
        setShowContent(true);
        setLoading(false);
      }, 100);
    } catch (error: any) {
      console.error('Error loading tasks:', error);
      toast.error(`Failed to load tasks: ${error.message}`);
      setShowContent(true);
      setLoading(false);
    }
  }, [currentPage, statusFilter, clusterFilter, structureFilter, typeFilter, sortBy, sortDirection, searchTerm, activeSector, pageSize]);

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

  // Listen for site and sector changes and refresh data
  useEffect(() => {
    const handleSiteChange = () => {
      loadTasks();
    };
    
    const handleSectorChange = () => {
      loadTasks();
    };
    
    window.addEventListener('siteChanged', handleSiteChange);
    window.addEventListener('sectorChanged', handleSectorChange);
    return () => {
      window.removeEventListener('siteChanged', handleSiteChange);
      window.removeEventListener('sectorChanged', handleSectorChange);
    };
  }, [loadTasks]);

  // Reset to page 1 when pageSize changes
  useEffect(() => {
    setCurrentPage(1);
  }, [pageSize]);


  // Debounced search
  useEffect(() => {
    const timer = setTimeout(() => {
      if (currentPage === 1) {
        loadTasks();
      } else {
        setCurrentPage(1);
      }
    }, 500);

    return () => clearTimeout(timer);
  }, [searchTerm, currentPage, loadTasks]);

  // Handle sorting
  const handleSort = (field: string, direction: 'asc' | 'desc') => {
    setSortBy(field || 'created_at');
    setSortDirection(direction);
    setCurrentPage(1);
  };

  // Bulk status update handler
  const handleBulkUpdateStatus = useCallback(async (ids: string[], status: string) => {
    try {
      const numIds = ids.map(id => parseInt(id));
      await bulkUpdateTasksStatus(numIds, status);
      await loadTasks();
    } catch (error: any) {
      throw error;
    }
  }, [loadTasks]);

  // Bulk export handler
  const handleBulkExport = useCallback(async (ids: string[]) => {
    try {
      if (!ids || ids.length === 0) {
        throw new Error('No records selected for export');
      }
      toast.info('Export functionality coming soon');
    } catch (error: any) {
      throw error;
    }
  }, []);

  // Row action handler for single task actions
  const handleRowAction = useCallback(async (action: string, row: Task) => {
    if (action === 'generate_content') {
      // Validate task has required data
      if (!row.title) {
        toast.error('Task must have a title to generate content');
        return;
      }
      
      // Optional: Validate task status (can generate for any status)
      // if (row.status !== 'queued') {
      //   toast.error(`Only tasks with status "queued" can generate content. Current status: ${row.status}`);
      //   return;
      // }
      
      try {
        const result = await autoGenerateContent([row.id]);
        
        if (result.success) {
          if (result.task_id) {
            // Async task - show progress modal
            progressModal.openModal(result.task_id, 'Generating Content', 'ai-generate-content-03');
            toast.success('Content generation started');
          } else {
            // Synchronous completion
            toast.success(`Content generated successfully: ${result.tasks_updated || 0} article generated`);
            await loadTasks();
          }
        } else {
          toast.error(result.error || 'Failed to generate content');
        }
      } catch (error: any) {
        toast.error(`Failed to generate content: ${error.message}`);
      }
    }
  }, [toast, loadTasks, progressModal]);

  // Bulk action handler
  const handleBulkAction = useCallback(async (action: string, ids: string[]) => {
    // generate_content removed from bulk actions - only available as row action
    if (action === 'generate_images') {
      if (ids.length === 0) {
        toast.error('Please select at least one task to generate images');
        return;
      }
      if (ids.length > 10) {
        toast.error('Maximum 10 tasks allowed for image generation');
        return;
      }
      const numIds = ids.map(id => parseInt(id));
      const selectedTasks = tasks.filter(t => numIds.includes(t.id));
      
      try {
        const result = await autoGenerateImages(numIds);
        if (result.success) {
          if (result.task_id) {
            // Async task - show progress modal
            progressModal.openModal(result.task_id, 'Generating Images');
            toast.success('Image generation started');
          } else {
            // Synchronous completion
            toast.success(`Image generation complete: ${result.images_created || 0} images generated`);
            await loadTasks();
          }
        } else {
          toast.error(result.error || 'Failed to generate images');
        }
      } catch (error: any) {
        toast.error(`Failed to generate images: ${error.message}`);
      }
    } else {
      toast.info(`Bulk action "${action}" for ${ids.length} items`);
    }
  }, [toast, loadTasks, progressModal, tasks]);

  // Reset reload flag when modal closes or opens
  useEffect(() => {
    if (!progressModal.isOpen) {
      hasReloadedRef.current = false; // Reset reload flag when modal closes
    } else {
      // Reset reload flag when modal opens for a new task
      hasReloadedRef.current = false;
    }
  }, [progressModal.isOpen, progressModal.taskId]);

  // Create page config
  const pageConfig = useMemo(() => {
    return createTasksPageConfig({
      clusters,
      activeSector,
      formData,
      setFormData,
      searchTerm,
      setSearchTerm,
      statusFilter,
      setStatusFilter,
      clusterFilter,
      sourceFilter,
      setSourceFilter,
      setClusterFilter,
      structureFilter,
      setStructureFilter,
      typeFilter,
      setTypeFilter,
      setCurrentPage,
    });
  }, [clusters, activeSector, formData, searchTerm, statusFilter, clusterFilter, structureFilter, typeFilter, sourceFilter]);

  // Calculate header metrics
  const headerMetrics = useMemo(() => {
    if (!pageConfig?.headerMetrics) return [];
    return pageConfig.headerMetrics.map((metric) => ({
      label: metric.label,
      value: metric.calculate({ tasks, totalCount }),
      accentColor: metric.accentColor,
      tooltip: (metric as any).tooltip,
    }));
  }, [pageConfig?.headerMetrics, tasks, totalCount]);

  const resetForm = useCallback(() => {
    setFormData({
      title: '',
      description: '',
      keywords: '',
      cluster_id: null,
      content_structure: 'article',
      content_type: 'post',
      status: 'queued',
      word_count: 0,
    });
    setIsEditMode(false);
    setEditingTask(null);
  }, []);

  // Handle create/edit
  const handleSave = async () => {
    try {
      if (isEditMode && editingTask) {
        await updateTask(editingTask.id, formData);
        toast.success('Task updated successfully');
      } else {
        await createTask(formData);
        toast.success('Task created successfully');
      }
      setIsModalOpen(false);
      resetForm();
      loadTasks();
    } catch (error: any) {
      toast.error(`Failed to save: ${error.message}`);
    }
  };

  // Writer navigation tabs
  const writerTabs = [
    { label: 'Ready to Write', path: '/writer/tasks', icon: <TaskIcon /> },
    { label: 'Finished Drafts', path: '/writer/content', icon: <FileIcon /> },
    { label: 'Article Images', path: '/writer/images', icon: <ImageIcon /> },
    { label: 'Review Before Publishing', path: '/writer/review', icon: <CheckCircleIcon /> },
    { label: 'Published', path: '/writer/published', icon: <CheckCircleIcon /> },
  ];

  return (
    <>
      <PageHeader 
        title="Write Your Articles" 
        badge={{ icon: <TaskIcon />, color: 'indigo' }}
        navigation={<ModuleNavigationTabs tabs={writerTabs} />}
        workflowInsights={workflowInsights}
      />
      <TablePageTemplate
          columns={pageConfig.columns}
          data={tasks}
          loading={loading}
          showContent={showContent}
          filters={pageConfig.filters}
          filterValues={{
            search: searchTerm,
            status: statusFilter,
            cluster_id: clusterFilter,
            content_structure: structureFilter,
            content_type: typeFilter,
            source: sourceFilter,
          }}
          onFilterChange={(key, value) => {
            const stringValue = value === null || value === undefined ? '' : String(value);
            if (key === 'search') {
              setSearchTerm(stringValue);
            } else if (key === 'status') {
              setStatusFilter(stringValue);
            } else if (key === 'cluster_id') {
              setClusterFilter(stringValue);
            } else if (key === 'content_structure') {
              setStructureFilter(stringValue);
            } else if (key === 'content_type') {
              setTypeFilter(stringValue);
            } else if (key === 'source') {
              setSourceFilter(stringValue);
            }
            setCurrentPage(1);
          }}
          onEdit={(row) => {
            setEditingTask(row);
            setFormData({
              title: row.title || '',
              description: row.description || '',
              keywords: row.keywords || '',
              cluster_id: row.cluster_id || null,
              content_structure: row.content_structure || 'article',
              content_type: row.content_type || 'post',
              status: row.status || 'queued',
              word_count: row.word_count || 0,
            });
            setIsEditMode(true);
            setIsModalOpen(true);
          }}
          onCreate={() => {
            resetForm();
            setIsModalOpen(true);
          }}
          createLabel="Add Task"
          onCreateIcon={<PlusIcon />}
          onDelete={async (id: number) => {
            await deleteTask(id);
            loadTasks();
          }}
          onBulkDelete={async (ids: number[]) => {
            const result = await bulkDeleteTasks(ids);
            // Clear selection first
            setSelectedIds([]);
            // Reset to page 1 if we deleted all items on current page
            if (currentPage > 1 && tasks.length <= ids.length) {
              setCurrentPage(1);
            }
            // Always reload data to refresh the table
            await loadTasks();
            return result;
          }}
          onBulkExport={handleBulkExport}
          onBulkUpdateStatus={handleBulkUpdateStatus}
          onBulkAction={handleBulkAction}
          onRowAction={handleRowAction}
          getItemDisplayName={(row: Task) => row.title}
          onExport={async () => {
            toast.info('Export functionality coming soon');
          }}
          onExportIcon={<DownloadIcon />}
          selectionLabel="task"
          pagination={{
            currentPage,
            totalPages,
            totalCount,
            onPageChange: setCurrentPage,
          }}
          selection={{
            selectedIds,
            onSelectionChange: setSelectedIds,
          }}
          sorting={{
            sortBy,
            sortDirection,
            onSort: handleSort,
          }}
          headerMetrics={headerMetrics}
          onFilterReset={() => {
            setSearchTerm('');
            setStatusFilter('');
            setClusterFilter('');
            setStructureFilter('');
            setTypeFilter('');
            setCurrentPage(1);
          }}
        />

      {/* Module Metrics Footer - Pipeline Style with Cross-Module Links */}
      <ModuleMetricsFooter
        metrics={[
          {
            title: 'Ideas',
            value: clusters.reduce((sum, c) => sum + (c.ideas_count || 0), 0).toLocaleString(),
            subtitle: 'from planner',
            icon: <TaskIcon className="w-5 h-5" />,
            accentColor: 'orange',
            href: '/planner/ideas',
          },
          {
            title: 'In Queue',
            value: tasks.filter(t => t.status === 'queued').length.toLocaleString(),
            subtitle: 'waiting for processing',
            icon: <TaskIcon className="w-5 h-5" />,
            accentColor: 'amber',
          },
          {
            title: 'Processing',
            value: tasks.filter(t => t.status === 'in_progress').length.toLocaleString(),
            subtitle: 'generating content',
            icon: <TaskIcon className="w-5 h-5" />,
            accentColor: 'blue',
          },
          {
            title: 'Ready for Review',
            value: tasks.filter(t => t.status === 'completed').length.toLocaleString(),
            subtitle: 'content generated',
            icon: <CheckCircleIcon className="w-5 h-5" />,
            accentColor: 'green',
            href: '/writer/content',
          },
        ]}
        progress={{
          label: 'Content Generation Pipeline: Tasks successfully completed (Queued → Processing → Completed)',
          value: totalCount > 0 ? Math.round((tasks.filter(t => t.status === 'completed').length / totalCount) * 100) : 0,
          color: 'success',
        }}
      />

      {/* Progress Modal for AI Functions */}
      <ProgressModal
        isOpen={progressModal.isOpen}
        title={progressModal.title}
        percentage={progressModal.progress.percentage}
        status={progressModal.progress.status}
        message={progressModal.progress.message}
        details={progressModal.progress.details}
        taskId={progressModal.taskId || undefined}
        functionId={progressModal.functionId}
        onClose={() => {
          const wasCompleted = progressModal.progress.status === 'completed';
          progressModal.closeModal();
          // Reload data after modal closes (if completed)
          if (wasCompleted && !hasReloadedRef.current) {
            hasReloadedRef.current = true;
            loadTasks();
            setTimeout(() => {
              hasReloadedRef.current = false;
            }, 1000);
          }
        }}
      />

      {/* Create/Edit Modal */}
      <FormModal
        isOpen={isModalOpen}
        onClose={() => {
          setIsModalOpen(false);
          resetForm();
        }}
        onSubmit={handleSave}
        title={isEditMode ? 'Edit Task' : 'Add Task'}
        submitLabel={isEditMode ? 'Update' : 'Create'}
        fields={pageConfig.formFields(clusters)}
      />
    </>
  );
}
