from flask import Blueprint, render_template, redirect, url_for, flash, request, abort
from flask_login import current_user, login_required
from app import db
from models import Category, Topic, Post, Tag, Reaction, Report
from forms import CreateTopicForm, CreatePostForm, ReportForm
from datetime import datetime
import logging
from sqlalchemy import desc, func

# Set up logger
logger = logging.getLogger(__name__)

# Create blueprint
forum_bp = Blueprint('forum', __name__)

# Helper functions
def get_or_create_tags(tag_names):
    """Gets existing tags or creates new ones from a comma-separated string"""
    if not tag_names:
        return []
    
    tags = []
    for name in [t.strip() for t in tag_names.split(',') if t.strip()]:
        tag = Tag.query.filter_by(name=name.lower()).first()
        if not tag:
            tag = Tag(name=name.lower())
            db.session.add(tag)
        tags.append(tag)
    
    return tags

# Routes
@forum_bp.route('/')
def index():
    categories = Category.query.order_by(Category.order).all()
    return render_template('home.html', categories=categories)

@forum_bp.route('/categories')
def category_list():
    categories = Category.query.order_by(Category.order).all()
    return render_template('forum/category_list.html', categories=categories)

@forum_bp.route('/category/<int:id>')
def category_view(id):
    category = Category.query.get_or_404(id)
    page = request.args.get('page', 1, type=int)
    per_page = 20  # Topics per page
    
    # Get topics with pagination
    topics = Topic.query.filter_by(category_id=id)\
        .order_by(Topic.is_pinned.desc(), Topic.updated_at.desc())\
        .paginate(page=page, per_page=per_page, error_out=False)
    
    return render_template('forum/topic_list.html', 
                           category=category, 
                           topics=topics)

@forum_bp.route('/topic/<int:id>', methods=['GET', 'POST'])
def topic_view(id):
    topic = Topic.query.get_or_404(id)
    
    # Increment view counter
    if not current_user.is_authenticated or current_user.id != topic.author_id:
        topic.increment_view()
    
    # Handle pagination
    page = request.args.get('page', 1, type=int)
    per_page = 10  # Posts per page
    posts = Post.query.filter_by(topic_id=id)\
        .order_by(Post.created_at)\
        .paginate(page=page, per_page=per_page, error_out=False)
    
    # Create forms
    post_form = CreatePostForm() if current_user.is_authenticated else None
    report_form = ReportForm() if current_user.is_authenticated else None
    
    # Handle post creation
    if current_user.is_authenticated and post_form and post_form.validate_on_submit():
        if topic.is_locked and not current_user.is_moderator():
            flash('This topic is locked. You cannot reply to it.', 'danger')
            return redirect(url_for('forum.topic_view', id=id))
        
        post = Post(
            content=post_form.content.data,
            topic_id=id,
            author_id=current_user.id
        )
        
        db.session.add(post)
        topic.updated_at = datetime.utcnow()
        db.session.commit()
        
        flash('Your reply has been posted!', 'success')
        return redirect(url_for('forum.topic_view', id=id, page=posts.pages or 1))
    
    return render_template('forum/topic_view.html', 
                           topic=topic, 
                           posts=posts, 
                           post_form=post_form,
                           report_form=report_form)

@forum_bp.route('/create_topic', methods=['GET', 'POST'])
@login_required
def create_topic():
    form = CreateTopicForm()
    
    # Populate category choices
    form.category_id.choices = [(c.id, c.name) for c in Category.query.order_by(Category.name).all()]
    
    if form.validate_on_submit():
        # Create new topic
        topic = Topic(
            title=form.title.data,
            category_id=form.category_id.data,
            author_id=current_user.id
        )
        
        # Add tags if provided
        if form.tags.data:
            topic.tags = get_or_create_tags(form.tags.data)
        
        db.session.add(topic)
        db.session.flush()  # Get the topic ID
        
        # Create the first post
        post = Post(
            content=form.content.data,
            topic_id=topic.id,
            author_id=current_user.id
        )
        
        db.session.add(post)
        db.session.commit()
        
        flash('Your topic has been created!', 'success')
        return redirect(url_for('forum.topic_view', id=topic.id))
    
    return render_template('forum/create_topic.html', form=form)

@forum_bp.route('/post/<int:id>/quote')
@login_required
def quote_post(id):
    post = Post.query.get_or_404(id)
    topic_id = post.topic_id
    
    if post.topic.is_locked and not current_user.is_moderator():
        flash('This topic is locked. You cannot reply to it.', 'danger')
        return redirect(url_for('forum.topic_view', id=topic_id))
    
    quoted_content = f'<blockquote><p>{post.content}</p><footer>Posted by {post.author.username}</footer></blockquote><p></p>'
    
    # Create a form and pre-fill it with the quoted content
    form = CreatePostForm(topic_id=topic_id, content=quoted_content)
    
    return render_template('forum/create_post.html', 
                          form=form, 
                          topic=post.topic,
                          is_quote=True)

@forum_bp.route('/post/<int:id>/edit', methods=['GET', 'POST'])
@login_required
def edit_post(id):
    post = Post.query.get_or_404(id)
    
    # Check permissions
    if current_user.id != post.author_id and not current_user.is_moderator():
        abort(403)
    
    # Create form and pre-fill with existing content
    form = CreatePostForm(topic_id=post.topic_id)
    
    if request.method == 'GET':
        form.content.data = post.content
    
    if form.validate_on_submit():
        post.content = form.content.data
        post.updated_at = datetime.utcnow()
        post.edited_by_id = current_user.id
        
        db.session.commit()
        flash('Your post has been updated!', 'success')
        return redirect(url_for('forum.topic_view', id=post.topic_id))
    
    return render_template('forum/create_post.html', 
                          form=form, 
                          topic=post.topic,
                          post=post,
                          is_edit=True)

@forum_bp.route('/post/<int:id>/delete', methods=['POST'])
@login_required
def delete_post(id):
    post = Post.query.get_or_404(id)
    topic_id = post.topic_id
    
    # Check permissions
    if current_user.id != post.author_id and not current_user.is_moderator():
        abort(403)
    
    # Check if this is the first post in a topic
    is_first_post = post.id == Post.query.filter_by(topic_id=topic_id).order_by(Post.created_at).first().id
    
    if is_first_post:
        # If first post, delete the entire topic
        topic = Topic.query.get(topic_id)
        db.session.delete(topic)  # This should cascade delete all posts
        db.session.commit()
        flash('The topic has been deleted!', 'success')
        return redirect(url_for('forum.category_view', id=topic.category_id))
    else:
        # Delete just this post
        db.session.delete(post)
        db.session.commit()
        flash('The post has been deleted!', 'success')
        return redirect(url_for('forum.topic_view', id=topic_id))

@forum_bp.route('/topic/<int:id>/lock', methods=['POST'])
@login_required
def lock_topic(id):
    if not current_user.is_moderator():
        abort(403)
    
    topic = Topic.query.get_or_404(id)
    topic.is_locked = not topic.is_locked  # Toggle lock state
    
    db.session.commit()
    
    status = 'locked' if topic.is_locked else 'unlocked'
    flash(f'The topic has been {status}!', 'success')
    
    return redirect(url_for('forum.topic_view', id=id))

@forum_bp.route('/topic/<int:id>/pin', methods=['POST'])
@login_required
def pin_topic(id):
    if not current_user.is_moderator():
        abort(403)
    
    topic = Topic.query.get_or_404(id)
    topic.is_pinned = not topic.is_pinned  # Toggle pin state
    
    db.session.commit()
    
    status = 'pinned' if topic.is_pinned else 'unpinned'
    flash(f'The topic has been {status}!', 'success')
    
    return redirect(url_for('forum.topic_view', id=id))

@forum_bp.route('/post/<int:post_id>/react', methods=['POST'])
@login_required
def react_to_post(post_id):
    post = Post.query.get_or_404(post_id)
    reaction_type = request.form.get('reaction_type', 'like')
    
    # Check if user already reacted
    existing_reaction = Reaction.query.filter_by(
        user_id=current_user.id,
        post_id=post_id
    ).first()
    
    if existing_reaction:
        if existing_reaction.reaction_type == reaction_type:
            # If same reaction, remove it
            db.session.delete(existing_reaction)
            db.session.commit()
            return {'status': 'removed', 'count': post.get_reaction_count(reaction_type)}
        else:
            # If different reaction, update it
            existing_reaction.reaction_type = reaction_type
            db.session.commit()
            return {'status': 'updated', 'count': post.get_reaction_count(reaction_type)}
    else:
        # Create new reaction
        reaction = Reaction(
            user_id=current_user.id,
            post_id=post_id,
            reaction_type=reaction_type
        )
        db.session.add(reaction)
        db.session.commit()
        return {'status': 'added', 'count': post.get_reaction_count(reaction_type)}

@forum_bp.route('/report', methods=['POST'])
@login_required
def create_report():
    form = ReportForm()
    
    if form.validate_on_submit():
        report = Report(
            reason=form.reason.data,
            reporter_id=current_user.id
        )
        
        # Set either post_id or topic_id
        if form.post_id.data:
            report.post_id = form.post_id.data
            item = Post.query.get_or_404(form.post_id.data)
            report.topic_id = item.topic_id
        elif form.topic_id.data:
            report.topic_id = form.topic_id.data
            item = Topic.query.get_or_404(form.topic_id.data)
        else:
            flash('Invalid report submission.', 'danger')
            return redirect(url_for('forum.index'))
        
        db.session.add(report)
        db.session.commit()
        
        flash('Your report has been submitted. A moderator will review it soon.', 'success')
        
        # Redirect back to the topic
        return redirect(url_for('forum.topic_view', id=report.topic_id))
    
    flash('There was an error with your report submission.', 'danger')
    return redirect(url_for('forum.index'))

@forum_bp.route('/tags/<tag_name>')
def tag_view(tag_name):
    tag = Tag.query.filter_by(name=tag_name.lower()).first_or_404()
    
    page = request.args.get('page', 1, type=int)
    per_page = 20
    
    topics = tag.topics.order_by(Topic.updated_at.desc())\
        .paginate(page=page, per_page=per_page, error_out=False)
    
    return render_template('forum/tag_topics.html', 
                          tag=tag, 
                          topics=topics)

@forum_bp.route('/search')
def search():
    query = request.args.get('q', '')
    page = request.args.get('page', 1, type=int)
    per_page = 20
    
    if not query or len(query) < 3:
        flash('Search query must be at least 3 characters long.', 'warning')
        return redirect(url_for('forum.index'))
    
    # Search in topics
    topics = Topic.query.filter(Topic.title.ilike(f'%{query}%'))\
        .order_by(Topic.updated_at.desc())\
        .paginate(page=page, per_page=per_page, error_out=False)
    
    return render_template('forum/search_results.html',
                           query=query,
                           topics=topics)