from fastapi import APIRouter, HTTPException, UploadFile, File, Form
from app.models.models import Meeting, TranscriptSegment, CreateMeetingRequest, UpdateMeetingRequest
from app.core.database import get_db_connection
from app.core.config import UPLOAD_DIR, AUDIO_DIR, ALLOWED_EXTENSIONS, MAX_FILE_SIZE
from typing import Optional
import os
import uuid
import shutil

router = APIRouter()

@router.get("/meetings", response_model=list[Meeting])
def get_meetings(user_id: Optional[int] = None):
    with get_db_connection() as connection:
        cursor = connection.cursor(dictionary=True)
        
        base_query = '''
            SELECT 
                m.meeting_id, m.title, m.meeting_time, m.summary, m.created_at, 
                m.user_id as creator_id, u.caption as creator_username
            FROM meetings m
            JOIN users u ON m.user_id = u.user_id
        '''
        
        if user_id:
            query = f'''
            {base_query}
            LEFT JOIN attendees a ON m.meeting_id = a.meeting_id
            WHERE m.user_id = %s OR a.user_id = %s
            GROUP BY m.meeting_id
            ORDER BY m.meeting_time DESC, m.created_at DESC
            '''
            cursor.execute(query, (user_id, user_id))
        else:
            query = f" {base_query} ORDER BY m.meeting_time DESC, m.created_at DESC"
            cursor.execute(query)
        
        meetings = cursor.fetchall()
        
        meeting_list = []
        for meeting in meetings:
            attendees_query = '''
            SELECT u.user_id, u.caption
            FROM attendees a
            JOIN users u ON a.user_id = u.user_id
            WHERE a.meeting_id = %s
            '''
            cursor.execute(attendees_query, (meeting['meeting_id'],))
            attendees_data = cursor.fetchall()
            attendees = [{'user_id': row['user_id'], 'caption': row['caption']} for row in attendees_data]
            
            meeting_list.append(Meeting(
                meeting_id=meeting['meeting_id'],
                title=meeting['title'],
                meeting_time=meeting['meeting_time'],
                summary=meeting['summary'],
                created_at=meeting['created_at'],
                attendees=attendees,
                creator_id=meeting['creator_id'],
                creator_username=meeting['creator_username']
            ))
        
        return meeting_list

@router.get("/meetings/{meeting_id}", response_model=Meeting)
def get_meeting_details(meeting_id: int):
    with get_db_connection() as connection:
        cursor = connection.cursor(dictionary=True)
        
        query = '''
            SELECT 
                m.meeting_id, m.title, m.meeting_time, m.summary, m.created_at, 
                m.user_id as creator_id, u.caption as creator_username,
                af.file_path as audio_file_path
            FROM meetings m
            JOIN users u ON m.user_id = u.user_id
            LEFT JOIN audio_files af ON m.meeting_id = af.meeting_id
            WHERE m.meeting_id = %s
        '''
        cursor.execute(query, (meeting_id,))
        meeting = cursor.fetchone()

        if not meeting:
            raise HTTPException(status_code=404, detail="Meeting not found")

        attendees_query = '''
        SELECT u.user_id, u.caption
        FROM attendees a
        JOIN users u ON a.user_id = u.user_id
        WHERE a.meeting_id = %s
        '''
        cursor.execute(attendees_query, (meeting['meeting_id'],))
        attendees_data = cursor.fetchall()
        attendees = [{'user_id': row['user_id'], 'caption': row['caption']} for row in attendees_data]

        meeting_data = Meeting(
            meeting_id=meeting['meeting_id'],
            title=meeting['title'],
            meeting_time=meeting['meeting_time'],
            summary=meeting['summary'],
            created_at=meeting['created_at'],
            attendees=attendees,
            creator_id=meeting['creator_id'],
            creator_username=meeting['creator_username']
        )
        
        # Add audio file path if exists
        if meeting['audio_file_path']:
            meeting_data.audio_file_path = meeting['audio_file_path']
        
        return meeting_data

@router.get("/meetings/{meeting_id}/transcript", response_model=list[TranscriptSegment])
def get_meeting_transcript(meeting_id: int):
    with get_db_connection() as connection:
        cursor = connection.cursor(dictionary=True)
        
        # First check if meeting exists
        meeting_query = "SELECT meeting_id FROM meetings WHERE meeting_id = %s"
        cursor.execute(meeting_query, (meeting_id,))
        if not cursor.fetchone():
            raise HTTPException(status_code=404, detail="Meeting not found")
        
        # Get transcript segments
        transcript_query = '''
            SELECT segment_id, meeting_id, speaker_tag, start_time_ms, end_time_ms, text_content
            FROM transcript_segments 
            WHERE meeting_id = %s 
            ORDER BY start_time_ms ASC
        '''
        cursor.execute(transcript_query, (meeting_id,))
        segments = cursor.fetchall()
        
        return [TranscriptSegment(**segment) for segment in segments]

@router.post("/meetings")
def create_meeting(meeting_request: CreateMeetingRequest):
    with get_db_connection() as connection:
        cursor = connection.cursor(dictionary=True)
        
        # Create meeting
        meeting_query = '''
            INSERT INTO meetings (user_id, title, meeting_time, summary)
            VALUES (%s, %s, %s, %s)
        '''
        # Note: You'll need to pass user_id, for now using hardcoded value
        cursor.execute(meeting_query, (1, meeting_request.title, meeting_request.meeting_time, None))
        meeting_id = cursor.lastrowid
        
        # Add attendees
        for attendee_id in meeting_request.attendee_ids:
            attendee_query = '''
                INSERT INTO attendees (meeting_id, user_id)
                VALUES (%s, %s)
                ON DUPLICATE KEY UPDATE meeting_id = meeting_id
            '''
            cursor.execute(attendee_query, (meeting_id, attendee_id))
        
        connection.commit()
        return {"meeting_id": meeting_id, "message": "Meeting created successfully"}

@router.put("/meetings/{meeting_id}")
def update_meeting(meeting_id: int, meeting_request: UpdateMeetingRequest):
    with get_db_connection() as connection:
        cursor = connection.cursor(dictionary=True)
        
        # Check if meeting exists
        cursor.execute("SELECT meeting_id FROM meetings WHERE meeting_id = %s", (meeting_id,))
        if not cursor.fetchone():
            raise HTTPException(status_code=404, detail="Meeting not found")
        
        # Update meeting
        update_query = '''
            UPDATE meetings 
            SET title = %s, meeting_time = %s, summary = %s
            WHERE meeting_id = %s
        '''
        cursor.execute(update_query, (
            meeting_request.title, 
            meeting_request.meeting_time, 
            meeting_request.summary,
            meeting_id
        ))
        
        # Update attendees - remove existing ones and add new ones
        cursor.execute("DELETE FROM attendees WHERE meeting_id = %s", (meeting_id,))
        
        for attendee_id in meeting_request.attendee_ids:
            attendee_query = '''
                INSERT INTO attendees (meeting_id, user_id)
                VALUES (%s, %s)
            '''
            cursor.execute(attendee_query, (meeting_id, attendee_id))
        
        connection.commit()
        return {"message": "Meeting updated successfully"}

@router.delete("/meetings/{meeting_id}")
def delete_meeting(meeting_id: int):
    with get_db_connection() as connection:
        cursor = connection.cursor(dictionary=True)
        
        # Check if meeting exists
        cursor.execute("SELECT meeting_id FROM meetings WHERE meeting_id = %s", (meeting_id,))
        if not cursor.fetchone():
            raise HTTPException(status_code=404, detail="Meeting not found")
        
        # Delete related records first (foreign key constraints)
        cursor.execute("DELETE FROM transcript_segments WHERE meeting_id = %s", (meeting_id,))
        cursor.execute("DELETE FROM audio_files WHERE meeting_id = %s", (meeting_id,))
        cursor.execute("DELETE FROM attachments WHERE meeting_id = %s", (meeting_id,))
        cursor.execute("DELETE FROM attendees WHERE meeting_id = %s", (meeting_id,))
        
        # Delete meeting
        cursor.execute("DELETE FROM meetings WHERE meeting_id = %s", (meeting_id,))
        
        connection.commit()
        return {"message": "Meeting deleted successfully"}

@router.post("/meetings/{meeting_id}/regenerate-summary")
def regenerate_summary(meeting_id: int):
    with get_db_connection() as connection:
        cursor = connection.cursor(dictionary=True)
        
        # Check if meeting exists
        cursor.execute("SELECT meeting_id FROM meetings WHERE meeting_id = %s", (meeting_id,))
        if not cursor.fetchone():
            raise HTTPException(status_code=404, detail="Meeting not found")
        
        # For now, return a mock summary
        # In a real implementation, this would call an AI service
        mock_summary = """# AI 生成摘要

## 主要议题
- 项目进度回顾
- 技术方案讨论
- 下阶段规划

## 关键决策
- 采用新的技术架构
- 调整项目时间节点
- 分配任务责任

## 后续行动
- [ ] 完成技术方案文档
- [ ] 安排下次会议时间
- [ ] 跟进项目进度"""
        
        # Update meeting summary
        cursor.execute(
            "UPDATE meetings SET summary = %s WHERE meeting_id = %s", 
            (mock_summary, meeting_id)
        )
        connection.commit()
        
        return {"summary": mock_summary}

@router.get("/meetings/{meeting_id}/edit", response_model=Meeting)
def get_meeting_for_edit(meeting_id: int):
    """Get meeting details with full attendee information for editing"""
    with get_db_connection() as connection:
        cursor = connection.cursor(dictionary=True)
        
        query = '''
            SELECT 
                m.meeting_id, m.title, m.meeting_time, m.summary, m.created_at, 
                m.user_id as creator_id, u.caption as creator_username,
                af.file_path as audio_file_path
            FROM meetings m
            JOIN users u ON m.user_id = u.user_id
            LEFT JOIN audio_files af ON m.meeting_id = af.meeting_id
            WHERE m.meeting_id = %s
        '''
        cursor.execute(query, (meeting_id,))
        meeting = cursor.fetchone()

        if not meeting:
            raise HTTPException(status_code=404, detail="Meeting not found")

        # Get attendees with full info for editing
        attendees_query = '''
        SELECT u.user_id, u.caption
        FROM attendees a
        JOIN users u ON a.user_id = u.user_id
        WHERE a.meeting_id = %s
        '''
        cursor.execute(attendees_query, (meeting['meeting_id'],))
        attendees_data = cursor.fetchall()
        attendees = [{'user_id': row['user_id'], 'caption': row['caption']} for row in attendees_data]

        meeting_data = Meeting(
            meeting_id=meeting['meeting_id'],
            title=meeting['title'],
            meeting_time=meeting['meeting_time'],
            summary=meeting['summary'],
            created_at=meeting['created_at'],
            attendees=attendees,
            creator_id=meeting['creator_id'],
            creator_username=meeting['creator_username']
        )
        
        # Add audio file path if exists
        if meeting['audio_file_path']:
            meeting_data.audio_file_path = meeting['audio_file_path']
        
        return meeting_data

@router.post("/meetings/upload-audio")
async def upload_audio(
    audio_file: UploadFile = File(...),
    meeting_id: int = Form(...)
):
    # Validate file extension
    file_extension = os.path.splitext(audio_file.filename)[1].lower()
    if file_extension not in ALLOWED_EXTENSIONS:
        raise HTTPException(
            status_code=400, 
            detail=f"Unsupported file type. Allowed types: {', '.join(ALLOWED_EXTENSIONS)}"
        )
    
    # Check file size
    if audio_file.size > MAX_FILE_SIZE:
        raise HTTPException(
            status_code=400,
            detail="File size exceeds 100MB limit"
        )
    
    # Generate unique filename
    unique_filename = f"{uuid.uuid4()}{file_extension}"
    file_path = AUDIO_DIR / unique_filename
    
    # Store only relative path for database (audio/filename)
    relative_path = f"audio/{unique_filename}"
    
    # Save file
    try:
        with open(file_path, "wb") as buffer:
            shutil.copyfileobj(audio_file.file, buffer)
    except Exception as e:
        raise HTTPException(status_code=500, detail=f"Failed to save file: {str(e)}")
    
    # Save file info to database
    with get_db_connection() as connection:
        cursor = connection.cursor(dictionary=True)
        
        # Check if meeting exists
        cursor.execute("SELECT meeting_id FROM meetings WHERE meeting_id = %s", (meeting_id,))
        if not cursor.fetchone():
            # Clean up uploaded file if meeting doesn't exist
            os.remove(file_path)
            raise HTTPException(status_code=404, detail="Meeting not found")
        
        # Insert audio file record
        insert_query = '''
            INSERT INTO audio_files (meeting_id, file_name, file_path, file_size, upload_time)
            VALUES (%s, %s, %s, %s, NOW())
            ON DUPLICATE KEY UPDATE
            file_name = VALUES(file_name),
            file_path = VALUES(file_path),
            file_size = VALUES(file_size),
            upload_time = VALUES(upload_time)
        '''
        cursor.execute(insert_query, (meeting_id, audio_file.filename, relative_path, audio_file.size))
        connection.commit()
    
    return {
        "message": "Audio file uploaded successfully",
        "file_name": audio_file.filename,
        "file_path": relative_path
    }

@router.get("/meetings/{meeting_id}/audio")
def get_audio_file(meeting_id: int):
    with get_db_connection() as connection:
        cursor = connection.cursor(dictionary=True)
        
        query = '''
            SELECT file_name, file_path, file_size, upload_time
            FROM audio_files 
            WHERE meeting_id = %s
        '''
        cursor.execute(query, (meeting_id,))
        audio_file = cursor.fetchone()
        
        if not audio_file:
            raise HTTPException(status_code=404, detail="Audio file not found for this meeting")
        
        return {
            "file_name": audio_file['file_name'],
            "file_path": audio_file['file_path'],
            "file_size": audio_file['file_size'],
            "upload_time": audio_file['upload_time']
        }