import os
import uuid
import base64
import cv2
import numpy as np
import json
from datetime import datetime
from flask import current_app, request, jsonify, render_template, url_for, Response
from .common import main_bp, get_db_connection, login_required, current_user
from processing import crop_image_perspective, remove_color_from_image, create_pdf_from_full_images
from redact import redact_pictures_in_image
from strings import ROUTE_PROCESS_CROP_V2, METHOD_POST

NVIDIA_API_KEY = os.getenv("NVIDIA_API_KEY")
NVIDIA_NIM_AVAILABLE = bool(NVIDIA_API_KEY)

@main_bp.route('/cropv2/<session_id>/<int:image_index>')
@login_required
def crop_interface_v2(session_id, image_index):
    conn = get_db_connection()
    session_owner = conn.execute('SELECT user_id FROM sessions WHERE id = ?', (session_id,)).fetchone()
    if not session_owner or session_owner['user_id'] != current_user.id:
        conn.close(); return "Unauthorized", 403

    # Check if two-page mode is enabled
    two_page_mode = getattr(current_user, 'two_page_crop', 0)

    if two_page_mode:
        # In two-page mode, image_index represents the pair index (0 = pages 0-1, 1 = pages 2-3, etc.)
        pair_index = image_index
        left_page_index = pair_index * 2
        right_page_index = left_page_index + 1

        left_image = conn.execute("SELECT * FROM images WHERE session_id = ? AND image_index = ? AND image_type = 'original'", (session_id, left_page_index)).fetchone()
        right_image = conn.execute("SELECT * FROM images WHERE session_id = ? AND image_index = ? AND image_type = 'original'", (session_id, right_page_index)).fetchone()

        if not left_image:
            conn.close(); return "Original page/image not found.", 404

        total_pages = conn.execute("SELECT COUNT(*) FROM images WHERE session_id = ? AND image_type = 'original'", (session_id,)).fetchone()[0]
        total_pairs = (total_pages + 1) // 2  # Round up for odd number of pages

        all_pages = [{'image_index': row['image_index'], 'filename': row['filename']} for row in conn.execute("SELECT image_index, filename FROM images WHERE session_id = ? AND image_type = 'original' ORDER BY image_index ASC", (session_id,)).fetchall()]
        conn.close()

        return render_template('cropv2.html',
            session_id=session_id,
            user_id=current_user.id,
            image_index=pair_index,
            image_info=left_image,
            right_image_info=dict(right_image) if right_image else None,
            total_pages=total_pairs,
            all_pages=all_pages,
            two_page_mode=True,
            left_page_index=left_page_index,
            right_page_index=right_page_index
        )
    else:
        # Standard single-page mode
        image_info = conn.execute("SELECT * FROM images WHERE session_id = ? AND image_index = ? AND image_type = 'original'", (session_id, image_index)).fetchone()
        if not image_info: conn.close(); return "Original page/image not found.", 404
        total_pages = conn.execute("SELECT COUNT(*) FROM images WHERE session_id = ? AND image_type = 'original'", (session_id,)).fetchone()[0]
        all_pages = [{'image_index': row['image_index'], 'filename': row['filename']} for row in conn.execute("SELECT image_index, filename FROM images WHERE session_id = ? AND image_type = 'original' ORDER BY image_index ASC", (session_id,)).fetchall()]
        conn.close()
        return render_template('cropv2.html',
            session_id=session_id,
            user_id=current_user.id,
            image_index=image_index,
            image_info=image_info,
            total_pages=total_pages,
            all_pages=all_pages,
            two_page_mode=False
        )

@main_bp.route(ROUTE_PROCESS_CROP_V2, methods=[METHOD_POST])
@login_required
def process_crop_v2():
    data = request.json
    session_id, page_index, boxes_data, image_data_url = data['session_id'], data['image_index'], data['boxes'], data.get('imageData')
    conn = get_db_connection()
    session_owner = conn.execute('SELECT user_id FROM sessions WHERE id = ?', (session_id,)).fetchone()
    if not session_owner or session_owner['user_id'] != current_user.id:
        conn.close(); return jsonify({'error': 'Unauthorized'}), 403
    page_info = conn.execute("SELECT filename FROM images WHERE session_id = ? AND image_index = ? AND image_type = 'original'", (session_id, page_index)).fetchone()
    if not page_info: conn.close(); return jsonify({'error': 'Original page not found'}), 404
    try:
        header, encoded = image_data_url.split(",", 1)
        image_data = base64.b64decode(encoded)
        temp_filename = f"temp_filtered_{page_info['filename']}"
        temp_path = os.path.join(current_app.config['PROCESSED_FOLDER'], temp_filename)
        with open(temp_path, "wb") as f: f.write(image_data)
        existing_cropped = conn.execute("SELECT id, processed_filename FROM images WHERE session_id = ? AND filename = ? AND image_type = 'cropped'", (session_id, page_info['filename'])).fetchall()
        for cropped_img in existing_cropped:
            if cropped_img['processed_filename']:
                try: os.remove(os.path.join(current_app.config['PROCESSED_FOLDER'], cropped_img['processed_filename']))
                except OSError: pass
            conn.execute("DELETE FROM questions WHERE session_id = ? AND image_id = ?", (session_id, cropped_img['id']))
        conn.execute("DELETE FROM images WHERE session_id = ? AND filename = ? AND image_type = 'cropped'", (session_id, page_info['filename']))
        local_source_ids = set()
        for box in boxes_data:
            if box.get('remote_stitch_source'):
                src = box['remote_stitch_source']
                if src.get('page_index') == page_index: local_source_ids.add(box['remote_stitch_source']['box']['id'])
        primary_boxes = [box for box in boxes_data if not box.get('stitch_to')]
        processed_boxes = []
        for i, primary_box in enumerate(primary_boxes):
            if primary_box['id'] in local_source_ids: continue
            if primary_box.get('remote_stitch_source'):
                source_info = primary_box['remote_stitch_source']
                source_page_index, source_box = source_info['page_index'], source_info['box']
                if 'id' in source_box:
                    source_img_row = conn.execute("SELECT id, processed_filename FROM images WHERE session_id = ? AND box_id = ?", (session_id, str(source_box['id']))).fetchone()
                    if source_img_row:
                        conn.execute("DELETE FROM questions WHERE image_id = ?", (source_img_row['id'],))
                        conn.execute("DELETE FROM images WHERE id = ?", (source_img_row['id'],))
                source_page_db = conn.execute("SELECT filename FROM images WHERE session_id = ? AND image_index = ? AND image_type = 'original'", (session_id, source_page_index)).fetchone()
                if source_page_db:
                    source_path = os.path.join(current_app.config['UPLOAD_FOLDER'], source_page_db['filename'])
                    if os.path.exists(source_path):
                        src_points = [{'x': source_box['x'], 'y': source_box['y']}, {'x': source_box['x'] + source_box['w'], 'y': source_box['y']}, {'x': source_box['x'] + source_box['w'], 'y': source_box['y'] + source_box['h']}, {'x': source_box['x'], 'y': source_box['y'] + source_box['h']}]
                        parent_crop = crop_image_perspective(source_path, src_points)
                        child_points = [{'x': primary_box['x'], 'y': primary_box['y']}, {'x': primary_box['x'] + primary_box['w'], 'y': primary_box['y']}, {'x': primary_box['x'] + primary_box['w'], 'y': primary_box['y'] + primary_box['h']}, {'x': primary_box['x'], 'y': primary_box['y'] + primary_box['h']}]
                        child_crop = crop_image_perspective(temp_path, child_points)
                        h1, w1 = parent_crop.shape[:2]; h2, w2 = child_crop.shape[:2]; max_width = max(w1, w2)
                        stitched_image = np.full((h1 + h2, max_width, 3), 255, dtype=np.uint8)
                        stitched_image[0:h1, (max_width - w1) // 2 : (max_width - w1) // 2 + w1] = parent_crop
                        stitched_image[h1:h1 + h2, (max_width - w2) // 2 : (max_width - w2) // 2 + w2] = child_crop
                    else: stitched_image = crop_image_perspective(temp_path, [{'x': primary_box['x'], 'y': primary_box['y']}, {'x': primary_box['x'] + primary_box['w'], 'y': primary_box['y']}, {'x': primary_box['x'] + primary_box['w'], 'y': primary_box['y'] + primary_box['h']}, {'x': primary_box['x'], 'y': primary_box['y'] + primary_box['h']}])
                else: stitched_image = crop_image_perspective(temp_path, [{'x': primary_box['x'], 'y': primary_box['y']}, {'x': primary_box['x'] + primary_box['w'], 'y': primary_box['y']}, {'x': primary_box['x'] + primary_box['w'], 'y': primary_box['y'] + primary_box['h']}, {'x': primary_box['x'], 'y': primary_box['y'] + primary_box['h']}])
            else:
                children = [box for box in boxes_data if box.get('stitch_to') == primary_box['id']]
                primary_crop = crop_image_perspective(temp_path, [{'x': primary_box['x'], 'y': primary_box['y']}, {'x': primary_box['x'] + primary_box['w'], 'y': primary_box['y']}, {'x': primary_box['x'] + primary_box['w'], 'y': primary_box['y'] + primary_box['h']}, {'x': primary_box['x'], 'y': primary_box['y'] + primary_box['h']}])
                stitched_image = primary_crop
                if children:
                    child = children[0]
                    child_crop = crop_image_perspective(temp_path, [{'x': child['x'], 'y': child['y']}, {'x': child['x'] + child['w'], 'y': child['y']}, {'x': child['x'] + child['w'], 'y': child['y'] + child['h']}, {'x': child['x'], 'y': child['y'] + child['h']}])
                    h1, w1 = primary_crop.shape[:2]; h2, w2 = child_crop.shape[:2]; max_width = max(w1, w2)
                    stitched_image = np.full((h1 + h2, max_width, 3), 255, dtype=np.uint8)
                    stitched_image[0:h1, (max_width - w1) // 2 : (max_width - w1) // 2 + w1] = primary_crop
                    stitched_image[h1:h1 + h2, (max_width - w2) // 2 : (max_width - w2) // 2 + w2] = child_crop
            crop_filename = f"processed_{session_id}_page{page_index}_crop{i}.jpg"
            cv2.imwrite(os.path.join(current_app.config['PROCESSED_FOLDER'], crop_filename), stitched_image)
            processed_boxes.append({'original_filename': page_info['filename'], 'processed_filename': crop_filename, 'box_id': str(primary_box['id']), 'question_number': primary_box.get('question_number'), 'status': primary_box.get('status'), 'marked_solution': primary_box.get('marked_solution'), 'actual_solution': primary_box.get('actual_solution')})
        max_idx = conn.execute('SELECT MAX(image_index) FROM images WHERE session_id = ?', (session_id,)).fetchone()[0]
        next_idx = (max_idx if max_idx is not None else -1) + 1
        for i, p_box in enumerate(processed_boxes):
            conn.execute('INSERT INTO images (session_id, image_index, filename, original_name, processed_filename, image_type, box_id) VALUES (?, ?, ?, ?, ?, ?, ?)', (session_id, next_idx + i, p_box['original_filename'], f"Page {page_index + 1} - Q{i + 1}", p_box['processed_filename'], 'cropped', p_box['box_id']))
            img_id = conn.execute('SELECT last_insert_rowid()').fetchone()[0]
            conn.execute("INSERT INTO questions (session_id, image_id, question_number, status, marked_solution, actual_solution) VALUES (?, ?, ?, ?, ?, ?)", (session_id, img_id, p_box.get('question_number'), p_box.get('status', 'unattempted'), p_box.get('marked_solution'), p_box.get('actual_solution')))
        conn.commit(); os.remove(temp_path); return jsonify({'success': True, 'processed_count': len(processed_boxes)})
    except Exception as e: conn.rollback(); return jsonify({'error': str(e)}), 500
    finally: conn.close()

@main_bp.route('/process_color_rm_batch', methods=['POST'])
@login_required
def process_color_rm_batch():
    data = request.json
    session_id, colors, threshold, bg_mode, region = data.get('session_id'), data.get('colors', []), data.get('threshold', 0.8), data.get('bg_mode', 'black'), data.get('region')
    conn = get_db_connection()
    session_owner = conn.execute('SELECT user_id FROM sessions WHERE id = ?', (session_id,)).fetchone()
    if not session_owner or session_owner['user_id'] != current_user.id:
        conn.close(); return jsonify({'error': 'Unauthorized'}), 403
    original_images = conn.execute("SELECT * FROM images WHERE session_id = ? AND image_type = 'original' ORDER BY image_index", (session_id,)).fetchall()
    processed_count = 0
    try:
        for img in original_images:
            original_path = os.path.join(current_app.config['UPLOAD_FOLDER'], img['filename'])
            if not os.path.exists(original_path): continue
            processed_img_cv = remove_color_from_image(original_path, colors, threshold, bg_mode, region)
            processed_filename = f"color_rm_{session_id}_{img['image_index']}_{datetime.now().strftime('%H%M%S')}.png"
            cv2.imwrite(os.path.join(current_app.config['PROCESSED_FOLDER'], processed_filename), processed_img_cv)
            existing = conn.execute("SELECT id FROM images WHERE session_id = ? AND image_index = ? AND image_type = 'color_rm'", (session_id, img['image_index'])).fetchone()
            if existing: conn.execute("UPDATE images SET processed_filename = ?, filename = ? WHERE id = ?", (processed_filename, img['filename'], existing['id']))
            else: conn.execute('INSERT INTO images (session_id, image_index, filename, original_name, processed_filename, image_type) VALUES (?, ?, ?, ?, ?, ?)', (session_id, img['image_index'], img['filename'], img['original_name'], processed_filename, 'color_rm'))
            processed_count += 1
        conn.commit(); return jsonify({'success': True, 'count': processed_count})
    except Exception as e: return jsonify({'error': str(e)}), 500
    finally: conn.close()

@main_bp.route('/color_rm')
@login_required
def color_rm_entry(): return render_template('color_rm_upload.html')

@main_bp.route('/color_rm_interface/<session_id>/<int:image_index>')
@login_required
def color_rm_interface(session_id, image_index):
    conn = get_db_connection()
    session_owner = conn.execute('SELECT user_id FROM sessions WHERE id = ?', (session_id,)).fetchone()
    if not session_owner or session_owner['user_id'] != current_user.id:
        conn.close(); return "Unauthorized", 403
    image_info = conn.execute("SELECT * FROM images WHERE session_id = ? AND image_index = ? AND image_type = 'original'", (session_id, image_index)).fetchone()
    if not image_info: conn.close(); return "Original page not found", 404
    total_pages = conn.execute("SELECT COUNT(*) FROM images WHERE session_id = ? AND image_type = 'original'", (session_id,)).fetchone()[0]
    conn.close()
    return render_template('color_rm.html', session_id=session_id, user_id=current_user.id, image_index=image_index, image_info=dict(image_info), total_pages=total_pages)

@main_bp.route('/process_color_rm', methods=['POST'])
@login_required
def process_color_rm():
    data = request.json
    sid, idx, url = data.get('session_id'), data.get('image_index'), data.get('imageData')
    conn = get_db_connection()
    session_owner = conn.execute('SELECT user_id FROM sessions WHERE id = ?', (sid,)).fetchone()
    if not session_owner or session_owner['user_id'] != current_user.id:
        conn.close(); return jsonify({'error': 'Unauthorized'}), 403
    page_info = conn.execute("SELECT filename, original_name FROM images WHERE session_id = ? AND image_index = ? AND image_type = 'original'", (sid, idx)).fetchone()
    if not page_info: conn.close(); return jsonify({'error': 'Original page not found'}), 404
    try:
        header, encoded = url.split(",", 1)
        image_data = base64.b64decode(encoded)
        fname = f"color_rm_{sid}_{idx}_{datetime.now().strftime('%H%M%S')}.png"
        with open(os.path.join(current_app.config['PROCESSED_FOLDER'], fname), "wb") as f: f.write(image_data)
        conn.execute('INSERT INTO images (session_id, image_index, filename, original_name, processed_filename, image_type) VALUES (?, ?, ?, ?, ?, ?)', (sid, idx, page_info['filename'], page_info['original_name'], fname, 'color_rm'))
        conn.commit(); return jsonify({'success': True, 'filename': fname, 'url': url_for('main.serve_processed_file', filename=fname)})
    except Exception as e: return jsonify({'error': str(e)}), 500
    finally: conn.close()

@main_bp.route('/redact_status/<session_id>')
@login_required
def redact_status(session_id):
    conn = get_db_connection()
    session_owner = conn.execute('SELECT user_id FROM sessions WHERE id = ?', (session_id,)).fetchone()
    conn.close()
    if not session_owner or session_owner['user_id'] != current_user.id: return "Unauthorized", 403
    return render_template('redact_status.html', session_id=session_id)

@main_bp.route('/redaction_stream/<session_id>')
@login_required
def redaction_stream(session_id):
    def generate():
        conn = get_db_connection()
        session_owner = conn.execute('SELECT user_id FROM sessions WHERE id = ?', (session_id,)).fetchone()
        if not session_owner or session_owner['user_id'] != current_user.id:
            conn.close(); yield f"data: {json.dumps({'error': 'Unauthorized'})}\n\n"; return
        if not NVIDIA_NIM_AVAILABLE: yield f"data: {json.dumps({'error': 'NVIDIA API Key not configured.'})}\n\n"; return
        images = conn.execute("SELECT id, filename FROM images WHERE session_id = ? AND image_type = 'original' ORDER BY image_index", (session_id,)).fetchall()
        if not images: conn.close(); yield f"data: {json.dumps({'error': 'No images found.'})}\n\n"; return
        redacted_paths, source_names, total = [], [], len(images)
        try:
            for i, img_row in enumerate(images):
                yield f"data: {json.dumps({'progress': int(((i + 1) / total) * 100), 'message': f'Redacting page {i + 1} of {total}...'})}\n\n"
                orig_path = os.path.join(current_app.config['UPLOAD_FOLDER'], img_row['filename'])
                if not os.path.exists(orig_path): continue
                redacted_img = redact_pictures_in_image(orig_path, NVIDIA_API_KEY)
                proc_name = f"redacted_{img_row['filename']}"
                proc_path = os.path.join(current_app.config['PROCESSED_FOLDER'], proc_name)
                redacted_img.save(proc_path, 'PNG'); redacted_paths.append(proc_path); source_names.append(img_row['filename'])
                conn.execute("UPDATE images SET processed_filename = ? WHERE id = ?", (proc_name, img_row['id'])); conn.commit()
            yield f"data: {json.dumps({'progress': 100, 'message': 'Assembling final PDF...'})}\n\n"
            pdf_name = f"redacted_document_{session_id}.pdf"
            pdf_path = os.path.join(current_app.config['OUTPUT_FOLDER'], pdf_name)
            if not create_pdf_from_full_images(redacted_paths, pdf_path): raise Exception("Failed to create PDF.")
            session_info = conn.execute('SELECT original_filename FROM sessions WHERE id = ?', (session_id,)).fetchone()
            conn.execute('INSERT INTO generated_pdfs (session_id, filename, subject, tags, notes, source_filename, user_id) VALUES (?, ?, ?, ?, ?, ?, ?)', (session_id, pdf_name, f"Redacted - {session_info['original_filename'] if session_info else 'Document'}", 'redacted', 'Automatically redacted.', ", ".join(source_names), current_user.id))
            conn.commit(); yield f"data: {json.dumps({'complete': True, 'download_url': url_for('main.download_file', filename=pdf_name)})}\n\n"
        except Exception as e: yield f"data: {json.dumps({'error': str(e)})}\n\n"
        finally: conn.close()
    return Response(generate(), mimetype='text/event-stream')