/**
 * Post Editor (Advanced)
 * Phase 7: Advanced Site Management
 * Full-featured editing: SEO, metadata, tags, categories, HTML content
 */
import React, { useState, useEffect } from 'react';
import { useParams, useNavigate } from 'react-router-dom';
import { SaveIcon, XIcon, EyeIcon, FileTextIcon, SettingsIcon, TagIcon, CheckCircleIcon, XCircleIcon, AlertCircleIcon } from 'lucide-react';
import PageMeta from '../../components/common/PageMeta';
import { Card } from '../../components/ui/card';
import Button from '../../components/ui/button/Button';
import Label from '../../components/form/Label';
import TextArea from '../../components/form/input/TextArea';
import SelectDropdown from '../../components/form/SelectDropdown';
import { useToast } from '../../components/ui/toast/ToastContainer';
import { fetchAPI, fetchContentValidation, validateContent, ContentValidationResult } from '../../services/api';

interface Content {
  id?: number;
  title: string;
  html_content?: string;
  content?: string;
  meta_title?: string;
  meta_description?: string;
  primary_keyword?: string;
  secondary_keywords?: string[];
  tags?: string[];
  categories?: string[];
  content_type: string;
  status: string;
  site: number;
  sector: number;
  word_count?: number;
  metadata?: Record<string, any>;
}

export default function PostEditor() {
  const { id: siteId, postId } = useParams<{ id: string; postId?: string }>();
  const navigate = useNavigate();
  const toast = useToast();
  const [loading, setLoading] = useState(true);
  const [saving, setSaving] = useState(false);
  const [activeTab, setActiveTab] = useState<'content' | 'seo' | 'metadata' | 'validation'>('content');
  const [validationResult, setValidationResult] = useState<ContentValidationResult | null>(null);
  const [validating, setValidating] = useState(false);
  const [content, setContent] = useState<Content>({
    title: '',
    html_content: '',
    content: '',
    meta_title: '',
    meta_description: '',
    primary_keyword: '',
    secondary_keywords: [],
    tags: [],
    categories: [],
    content_type: 'article',
    status: 'draft',
    site: Number(siteId),
    sector: 0, // Will be set from site
  });
  const [tagInput, setTagInput] = useState('');
  const [categoryInput, setCategoryInput] = useState('');

  useEffect(() => {
    if (siteId) {
      loadSite();
      if (postId && postId !== 'new') {
        loadPost();
        loadValidation();
      } else {
        setLoading(false);
      }
    }
  }, [siteId, postId]);

  const loadValidation = async () => {
    if (!postId || postId === 'new') return;
    try {
      const result = await fetchContentValidation(Number(postId));
      setValidationResult(result);
    } catch (error: any) {
      console.error('Failed to load validation:', error);
    }
  };

  const handleValidate = async () => {
    if (!content.id) {
      toast.error('Please save the content first before validating');
      return;
    }
    try {
      setValidating(true);
      const result = await validateContent(content.id);
      await loadValidation();
      if (result.is_valid) {
        toast.success('Content validation passed!');
      } else {
        toast.warning(`Validation found ${result.errors.length} issue(s)`);
      }
    } catch (error: any) {
      toast.error(`Validation failed: ${error.message}`);
    } finally {
      setValidating(false);
    }
  };

  const loadSite = async () => {
    try {
      const site = await fetchAPI(`/v1/auth/sites/${siteId}/`);
      if (site) {
        setContent((prev) => ({
          ...prev,
          sector: site.sector || 0,
        }));
      }
    } catch (error: any) {
      console.error('Failed to load site:', error);
    }
  };

  const loadPost = async () => {
    try {
      setLoading(true);
      const data = await fetchAPI(`/v1/writer/content/${postId}/`);
      if (data) {
        setContent({
          id: data.id,
          title: data.title || '',
          html_content: data.html_content || '',
          content: data.html_content || data.content || '',
          meta_title: data.meta_title || '',
          meta_description: data.meta_description || '',
          primary_keyword: data.primary_keyword || '',
          secondary_keywords: Array.isArray(data.secondary_keywords) ? data.secondary_keywords : [],
          tags: Array.isArray(data.tags) ? data.tags : [],
          categories: Array.isArray(data.categories) ? data.categories : [],
          content_type: 'article', // Content model doesn't have content_type
          status: data.status || 'draft',
          site: data.site || Number(siteId),
          sector: data.sector || 0,
          word_count: data.word_count || 0,
          metadata: data.metadata || {},
        });
      }
    } catch (error: any) {
      toast.error(`Failed to load post: ${error.message}`);
      navigate(`/sites/${siteId}/content`);
    } finally {
      setLoading(false);
    }
  };

  const handleSave = async () => {
    if (!content.title.trim()) {
      toast.error('Title is required');
      return;
    }

    try {
      setSaving(true);
      const payload = {
        ...content,
        html_content: content.html_content || content.content,
      };
      
      if (content.id) {
        // Update existing
        await fetchAPI(`/v1/writer/content/${content.id}/`, {
          method: 'PUT',
          body: JSON.stringify(payload),
        });
        toast.success('Post updated successfully');
      } else {
        // Create new - need to create a task first
        const taskData = await fetchAPI('/v1/writer/tasks/', {
          method: 'POST',
          body: JSON.stringify({
            title: content.title,
            description: content.meta_description || '',
            keywords: content.primary_keyword || '',
            site_id: content.site,
            sector_id: content.sector,
            content_type: 'article',
            content_structure: 'blog_post',
            status: 'completed',
          }),
        });
        
        if (taskData?.id) {
          const result = await fetchAPI('/v1/writer/content/', {
            method: 'POST',
            body: JSON.stringify({
              ...payload,
              task_id: taskData.id,
            }),
          });
          toast.success('Post created successfully');
          if (result?.id) {
            navigate(`/sites/${siteId}/posts/${result.id}/edit`);
          }
        }
      }
    } catch (error: any) {
      toast.error(`Failed to save post: ${error.message}`);
    } finally {
      setSaving(false);
    }
  };

  const handleAddTag = () => {
    if (tagInput.trim() && !content.tags?.includes(tagInput.trim())) {
      setContent({
        ...content,
        tags: [...(content.tags || []), tagInput.trim()],
      });
      setTagInput('');
    }
  };

  const handleRemoveTag = (tag: string) => {
    setContent({
      ...content,
      tags: content.tags?.filter((t) => t !== tag) || [],
    });
  };

  const handleAddCategory = () => {
    if (categoryInput.trim() && !content.categories?.includes(categoryInput.trim())) {
      setContent({
        ...content,
        categories: [...(content.categories || []), categoryInput.trim()],
      });
      setCategoryInput('');
    }
  };

  const handleRemoveCategory = (category: string) => {
    setContent({
      ...content,
      categories: content.categories?.filter((c) => c !== category) || [],
    });
  };

  const CONTENT_TYPES = [
    { value: 'article', label: 'Article' },
    { value: 'blog_post', label: 'Blog Post' },
    { value: 'page', label: 'Page' },
    { value: 'product', label: 'Product' },
  ];

  const STATUS_OPTIONS = [
    { value: 'draft', label: 'Draft' },
    { value: 'review', label: 'Review' },
    { value: 'publish', label: 'Published' },
  ];

  if (loading) {
    return (
      <div className="p-6">
        <PageMeta title="Post Editor" />
        <div className="flex items-center justify-center h-64">
          <div className="text-gray-500">Loading post...</div>
        </div>
      </div>
    );
  }

  return (
    <div className="p-6">
      <PageMeta title={content.id ? 'Edit Post' : 'New Post'} />
      
      <div className="mb-6 flex justify-between items-center">
        <div>
          <h1 className="text-2xl font-bold text-gray-900 dark:text-white">
            {content.id ? 'Edit Post' : 'New Post'}
          </h1>
          <p className="text-gray-600 dark:text-gray-400 mt-1">
            {content.id ? 'Edit your post content' : 'Create a new post'}
          </p>
        </div>
        <div className="flex gap-2">
          <Button
            variant="outline"
            onClick={() => navigate(`/sites/${siteId}/content`)}
          >
            <XIcon className="w-4 h-4 mr-2" />
            Cancel
          </Button>
          <Button
            variant="primary"
            onClick={handleSave}
            disabled={saving}
          >
            <SaveIcon className="w-4 h-4 mr-2" />
            {saving ? 'Saving...' : 'Save Post'}
          </Button>
        </div>
      </div>

      {/* Tabs */}
      <div className="mb-6 border-b border-gray-200 dark:border-gray-700">
        <div className="flex gap-4">
          <button
            type="button"
            onClick={() => setActiveTab('content')}
            className={`px-4 py-2 font-medium border-b-2 transition-colors ${
              activeTab === 'content'
                ? 'border-brand-500 text-brand-600 dark:text-brand-400'
                : 'border-transparent text-gray-500 hover:text-gray-700 dark:text-gray-400 dark:hover:text-gray-300'
            }`}
          >
            <FileTextIcon className="w-4 h-4 inline mr-2" />
            Content
          </button>
          <button
            type="button"
            onClick={() => setActiveTab('seo')}
            className={`px-4 py-2 font-medium border-b-2 transition-colors ${
              activeTab === 'seo'
                ? 'border-brand-500 text-brand-600 dark:text-brand-400'
                : 'border-transparent text-gray-500 hover:text-gray-700 dark:text-gray-400 dark:hover:text-gray-300'
            }`}
          >
            <EyeIcon className="w-4 h-4 inline mr-2" />
            SEO
          </button>
          <button
            type="button"
            onClick={() => setActiveTab('metadata')}
            className={`px-4 py-2 font-medium border-b-2 transition-colors ${
              activeTab === 'metadata'
                ? 'border-brand-500 text-brand-600 dark:text-brand-400'
                : 'border-transparent text-gray-500 hover:text-gray-700 dark:text-gray-400 dark:hover:text-gray-300'
            }`}
          >
            <TagIcon className="w-4 h-4 inline mr-2" />
            Metadata
          </button>
          {content.id && (
            <button
              type="button"
              onClick={() => {
                setActiveTab('validation');
                loadValidation();
              }}
              className={`px-4 py-2 font-medium border-b-2 transition-colors ${
                activeTab === 'validation'
                  ? 'border-brand-500 text-brand-600 dark:text-brand-400'
                  : 'border-transparent text-gray-500 hover:text-gray-700 dark:text-gray-400 dark:hover:text-gray-300'
              }`}
            >
              <CheckCircleIcon className="w-4 h-4 inline mr-2" />
              Validation
              {validationResult && !validationResult.is_valid && (
                <span className="ml-2 px-2 py-0.5 text-xs bg-red-100 dark:bg-red-900 text-red-600 dark:text-red-400 rounded-full">
                  {validationResult.validation_errors.length}
                </span>
              )}
            </button>
          )}
        </div>
      </div>

      <div className="space-y-6">
        {/* Content Tab */}
        {activeTab === 'content' && (
          <Card className="p-6">
            <div className="space-y-4">
              <div>
                <Label>Title *</Label>
                <input
                  type="text"
                  value={content.title}
                  onChange={(e) => setContent({ ...content, title: e.target.value })}
                  placeholder="Enter post title"
                  className="mt-1 w-full px-3 py-2 border border-gray-300 dark:border-gray-700 rounded-md dark:bg-gray-800 dark:text-white"
                />
              </div>

              <div className="grid grid-cols-2 gap-4">
                <div>
                  <Label>Content Type</Label>
                  <SelectDropdown
                    options={CONTENT_TYPES}
                    value={content.content_type}
                    onChange={(value) => setContent({ ...content, content_type: value })}
                  />
                </div>

                <div>
                  <Label>Status</Label>
                  <SelectDropdown
                    options={STATUS_OPTIONS}
                    value={content.status}
                    onChange={(value) => setContent({ ...content, status: value })}
                  />
                </div>
              </div>

              <div>
                <Label>Content (HTML)</Label>
                <TextArea
                  value={content.html_content || content.content}
                  onChange={(value) => setContent({ ...content, html_content: value, content: value })}
                  rows={25}
                  placeholder="Write your post content here (HTML supported)..."
                  className="mt-1 font-mono text-sm"
                />
                <p className="mt-1 text-xs text-gray-500 dark:text-gray-400">
                  HTML content is supported. Use &lt;p&gt;, &lt;h1&gt;, &lt;h2&gt;, etc. for formatting.
                </p>
              </div>

              {content.word_count !== undefined && content.word_count > 0 && (
                <div className="text-sm text-gray-600 dark:text-gray-400">
                  Word count: {content.word_count.toLocaleString()}
                </div>
              )}
            </div>
          </Card>
        )}

        {/* SEO Tab */}
        {activeTab === 'seo' && (
          <Card className="p-6">
            <div className="space-y-4">
              <div>
                <Label>Meta Title</Label>
                <input
                  type="text"
                  value={content.meta_title || ''}
                  onChange={(e) => setContent({ ...content, meta_title: e.target.value })}
                  placeholder="SEO title (recommended: 50-60 characters)"
                  maxLength={60}
                  className="mt-1 w-full px-3 py-2 border border-gray-300 dark:border-gray-700 rounded-md dark:bg-gray-800 dark:text-white"
                />
                <p className="mt-1 text-xs text-gray-500 dark:text-gray-400">
                  {content.meta_title?.length || 0}/60 characters
                </p>
              </div>

              <div>
                <Label>Meta Description</Label>
                <TextArea
                  value={content.meta_description || ''}
                  onChange={(value) => setContent({ ...content, meta_description: value })}
                  rows={4}
                  placeholder="SEO description (recommended: 150-160 characters)"
                  maxLength={160}
                  className="mt-1"
                />
                <p className="mt-1 text-xs text-gray-500 dark:text-gray-400">
                  {content.meta_description?.length || 0}/160 characters
                </p>
              </div>

              <div>
                <Label>Primary Keyword</Label>
                <input
                  type="text"
                  value={content.primary_keyword || ''}
                  onChange={(e) => setContent({ ...content, primary_keyword: e.target.value })}
                  placeholder="Main keyword for this content"
                  className="mt-1 w-full px-3 py-2 border border-gray-300 dark:border-gray-700 rounded-md dark:bg-gray-800 dark:text-white"
                />
              </div>

              <div>
                <Label>Secondary Keywords (comma-separated)</Label>
                <input
                  type="text"
                  value={content.secondary_keywords?.join(', ') || ''}
                  onChange={(e) => {
                    const keywords = e.target.value.split(',').map((k) => k.trim()).filter(Boolean);
                    setContent({ ...content, secondary_keywords: keywords });
                  }}
                  placeholder="keyword1, keyword2, keyword3"
                  className="mt-1 w-full px-3 py-2 border border-gray-300 dark:border-gray-700 rounded-md dark:bg-gray-800 dark:text-white"
                />
              </div>
            </div>
          </Card>
        )}

        {/* Metadata Tab */}
        {activeTab === 'metadata' && (
          <Card className="p-6">
            <div className="space-y-6">
              <div>
                <Label>Tags</Label>
                <div className="mt-2 flex gap-2">
                  <input
                    type="text"
                    value={tagInput}
                    onChange={(e) => setTagInput(e.target.value)}
                    onKeyPress={(e) => {
                      if (e.key === 'Enter') {
                        e.preventDefault();
                        handleAddTag();
                      }
                    }}
                    placeholder="Add a tag and press Enter"
                    className="flex-1 px-3 py-2 border border-gray-300 dark:border-gray-700 rounded-md dark:bg-gray-800 dark:text-white"
                  />
                  <Button type="button" onClick={handleAddTag} variant="outline">
                    Add
                  </Button>
                </div>
                {content.tags && content.tags.length > 0 && (
                  <div className="mt-3 flex flex-wrap gap-2">
                    {content.tags.map((tag) => (
                      <span
                        key={tag}
                        className="inline-flex items-center gap-1 px-3 py-1 bg-gray-100 dark:bg-gray-800 rounded-full text-sm"
                      >
                        {tag}
                        <button
                          type="button"
                          onClick={() => handleRemoveTag(tag)}
                          className="text-gray-500 hover:text-gray-700 dark:text-gray-400 dark:hover:text-gray-200"
                        >
                          ×
                        </button>
                      </span>
                    ))}
                  </div>
                )}
              </div>

              <div>
                <Label>Categories</Label>
                <div className="mt-2 flex gap-2">
                  <input
                    type="text"
                    value={categoryInput}
                    onChange={(e) => setCategoryInput(e.target.value)}
                    onKeyPress={(e) => {
                      if (e.key === 'Enter') {
                        e.preventDefault();
                        handleAddCategory();
                      }
                    }}
                    placeholder="Add a category and press Enter"
                    className="flex-1 px-3 py-2 border border-gray-300 dark:border-gray-700 rounded-md dark:bg-gray-800 dark:text-white"
                  />
                  <Button type="button" onClick={handleAddCategory} variant="outline">
                    Add
                  </Button>
                </div>
                {content.categories && content.categories.length > 0 && (
                  <div className="mt-3 flex flex-wrap gap-2">
                    {content.categories.map((category) => (
                      <span
                        key={category}
                        className="inline-flex items-center gap-1 px-3 py-1 bg-blue-100 dark:bg-blue-900 rounded-full text-sm"
                      >
                        {category}
                        <button
                          type="button"
                          onClick={() => handleRemoveCategory(category)}
                          className="text-blue-600 hover:text-blue-800 dark:text-blue-400 dark:hover:text-blue-200"
                        >
                          ×
                        </button>
                      </span>
                    ))}
                  </div>
                )}
              </div>
            </div>
          </Card>
        )}

        {/* Validation Tab - Stage 3 */}
        {activeTab === 'validation' && content.id && (
          <Card className="p-6">
            <div className="space-y-6">
              <div className="flex items-center justify-between">
                <div>
                  <h3 className="text-lg font-semibold text-gray-900 dark:text-white">
                    Content Validation
                  </h3>
                  <p className="text-sm text-gray-600 dark:text-gray-400 mt-1">
                    Check if your content meets all requirements before publishing
                  </p>
                </div>
                <Button
                  variant="primary"
                  onClick={handleValidate}
                  disabled={validating}
                >
                  {validating ? 'Validating...' : 'Run Validation'}
                </Button>
              </div>

              {validationResult ? (
                <div className="space-y-4">
                  {/* Validation Status */}
                  <div className={`p-4 rounded-lg ${
                    validationResult.is_valid
                      ? 'bg-green-50 dark:bg-green-900/20 border border-green-200 dark:border-green-800'
                      : 'bg-red-50 dark:bg-red-900/20 border border-red-200 dark:border-red-800'
                  }`}>
                    <div className="flex items-center gap-2">
                      {validationResult.is_valid ? (
                        <CheckCircleIcon className="w-5 h-5 text-green-600 dark:text-green-400" />
                      ) : (
                        <XCircleIcon className="w-5 h-5 text-red-600 dark:text-red-400" />
                      )}
                      <span className={`font-medium ${
                        validationResult.is_valid
                          ? 'text-green-800 dark:text-green-300'
                          : 'text-red-800 dark:text-red-300'
                      }`}>
                        {validationResult.is_valid
                          ? 'Content is valid and ready to publish'
                          : `Content has ${validationResult.validation_errors.length} validation error(s)`}
                      </span>
                    </div>
                  </div>

                  {/* Metadata Summary */}
                  <div className="bg-gray-50 dark:bg-gray-900 rounded-lg p-4">
                    <h4 className="text-sm font-semibold text-gray-900 dark:text-white mb-3">
                      Metadata Summary
                    </h4>
                    <div className="grid grid-cols-2 gap-4 text-sm">
                      <div>
                        <span className="text-gray-600 dark:text-gray-400">Entity Type:</span>
                        <span className="ml-2 font-medium text-gray-900 dark:text-white">
                          {validationResult.metadata.entity_type || 'Not set'}
                        </span>
                      </div>
                      <div>
                        <span className="text-gray-600 dark:text-gray-400">Cluster Mapping:</span>
                        <span className={`ml-2 font-medium ${
                          validationResult.metadata.has_cluster_mapping
                            ? 'text-green-600 dark:text-green-400'
                            : 'text-red-600 dark:text-red-400'
                        }`}>
                          {validationResult.metadata.has_cluster_mapping ? 'Yes' : 'No'}
                        </span>
                      </div>
                      <div>
                        <span className="text-gray-600 dark:text-gray-400">Taxonomy Mapping:</span>
                        <span className={`ml-2 font-medium ${
                          validationResult.metadata.has_taxonomy_mapping
                            ? 'text-green-600 dark:text-green-400'
                            : 'text-red-600 dark:text-red-400'
                        }`}>
                          {validationResult.metadata.has_taxonomy_mapping ? 'Yes' : 'No'}
                        </span>
                      </div>
                    </div>
                  </div>

                  {/* Validation Errors */}
                  {validationResult.validation_errors.length > 0 && (
                    <div>
                      <h4 className="text-sm font-semibold text-gray-900 dark:text-white mb-3">
                        Validation Errors
                      </h4>
                      <div className="space-y-2">
                        {validationResult.validation_errors.map((error, index) => (
                          <div
                            key={index}
                            className="flex items-start gap-2 p-3 bg-red-50 dark:bg-red-900/20 rounded-lg border border-red-200 dark:border-red-800"
                          >
                            <AlertCircleIcon className="w-5 h-5 text-red-600 dark:text-red-400 flex-shrink-0 mt-0.5" />
                            <div className="flex-1">
                              <div className="text-sm font-medium text-red-800 dark:text-red-300">
                                {error.field || error.code}
                              </div>
                              <div className="text-sm text-red-600 dark:text-red-400 mt-1">
                                {error.message}
                              </div>
                            </div>
                          </div>
                        ))}
                      </div>
                    </div>
                  )}

                  {/* Publish Errors */}
                  {validationResult.publish_errors && validationResult.publish_errors.length > 0 && (
                    <div>
                      <h4 className="text-sm font-semibold text-gray-900 dark:text-white mb-3">
                        Publish Blockers
                      </h4>
                      <div className="space-y-2">
                        {validationResult.publish_errors.map((error, index) => (
                          <div
                            key={index}
                            className="flex items-start gap-2 p-3 bg-orange-50 dark:bg-orange-900/20 rounded-lg border border-orange-200 dark:border-orange-800"
                          >
                            <XCircleIcon className="w-5 h-5 text-orange-600 dark:text-orange-400 flex-shrink-0 mt-0.5" />
                            <div className="flex-1">
                              <div className="text-sm font-medium text-orange-800 dark:text-orange-300">
                                {error.field || error.code}
                              </div>
                              <div className="text-sm text-orange-600 dark:text-orange-400 mt-1">
                                {error.message}
                              </div>
                            </div>
                          </div>
                        ))}
                      </div>
                    </div>
                  )}
                </div>
              ) : (
                <div className="text-center py-8 text-gray-500 dark:text-gray-400">
                  <p>Click "Run Validation" to check your content</p>
                </div>
              )}
            </div>
          </Card>
        )}
      </div>
    </div>
  );
}

