import asyncio
import codecs
import functools
import io
import time

import chromadb
from aiohttp import web
from chromadb.config import Settings
from chromadb.utils import embedding_functions
from chromadb.api.models.Collection import Collection
import logging
from pathlib import Path
from config import (
    DATABASE_DIR,
    HTTP_HOST,
    HTTP_PORT,
    QUIET,
    WEBDATA_DIR,
    COLLECTION_NAME,
    MODEL_NAME,
    TORCH_DEVICE,
)
from rich.logging import RichHandler
from rich.console import Console
from concurrent.futures import ThreadPoolExecutor
import uuid
import csv


log = logging.getLogger(__name__)
COLLECTION: Collection = None
executor = ThreadPoolExecutor(1)
routes = web.RouteTableDef()
WEBDATA_DIR = Path(WEBDATA_DIR)

async def async_run(func, /, *args, **kwargs):
    loop = asyncio.get_running_loop()
    task = loop.run_in_executor(executor, functools.partial(func, *args, **kwargs))
    results = await asyncio.gather(task)
    return results[0]


@routes.get('/')
async def serve_index(request):
    return web.FileResponse(WEBDATA_DIR / 'index.html')


@routes.get('/favicon.ico')
async def serve_favicon(request):
    return web.FileResponse(WEBDATA_DIR / 'favicon.ico')


@routes.post('/api/v1/search')
async def add_items(request):
    data = await request.json()
    results = await async_run(
        COLLECTION.query,
        query_texts=[data.get('text', '')],
        n_results=10,
    )
    items = [
        [
            results['ids'][0][i],
            results['distances'][0][i],
            results['documents'][0][i],
            results['metadatas'][0][i],
        ] for i in range(len(results['ids'][0]))
    ]
    return web.json_response(items)


@routes.post('/api/v1/item')
async def add_items(request):
    data = await request.json()
    ids = []
    metadatas = []
    documents = []
    body = data.get('body', '')
    source = data.get('source')
    search_sources = source == '#'
    if search_sources:
        source = ''

    divisions = body.split('\n\n')
    for items in divisions:
        lines = [line for line in items.split('\n') if line.strip()]
        if len(lines) == 0:
            continue
        if search_sources and lines[0].startswith('#'):
            source = lines[0].lstrip('#').strip()
            continue
        title = ''
        if len(lines) >= 2:
            title = lines[0]
            lines = lines[1:]
        else:
            pass
        doc = ' '.join(lines)
        doc = ' '.join(doc.split()).strip() # this just replaces extra whitespaces with one.
        if len(doc) == 0:
            continue
        ids.append(uuid.uuid4().hex)
        documents.append(doc)
        metadatas.append({'type': 'question', 'source': source, 'added': int(time.time()), 'title': title})
    await async_run(COLLECTION.upsert, ids=ids, metadatas=metadatas, documents=documents)
    return web.json_response({'count': await async_run(COLLECTION.count)})


@routes.delete('/api/v1/item')
async def delete_item(request: web.BaseRequest):
    await async_run(COLLECTION.delete, ids=[request.query.get('id')])
    return


@routes.get('/api/v1/database')
async def get_database(request: web.BaseRequest):
    results = await async_run(COLLECTION.get)
    buffer = io.StringIO()
    writer = csv.writer(buffer)
    writer.writerow(['ID', 'Source', 'Title', 'Document'])
    for i in range(len(results['ids'])):
        writer.writerow([
            results["ids"][i], results['metadatas'][i]['source'],
            results["metadatas"][i]["title"], results['documents'][i]
        ])
    return web.Response(text=buffer.getvalue(), status=200, content_type='text/csv',
                        headers={'Content-Disposition': 'attachment; filename=ipt_questions.csv'})


@routes.post('/api/v1/database')
async def get_database(request: web.BaseRequest):
    data = await request.post()
    ids = []
    documents = []
    metadatas = []
    body = codecs.getreader('utf-8')(data['database'].file)
    reader = csv.reader(body)
    header = next(reader)
    if ','.join(header) != 'ID,Source,Title,Document':
        return web.Response(text='Invalid CSV header', status=400)
    for row in reader:
        ids.append(row[0])
        documents.append(row[3])
        metadatas.append({"type": "question", "source": row[1], "added": int(time.time()), "title": row[2]})
    await async_run(COLLECTION.upsert, ids=ids, metadatas=metadatas, documents=documents)
    return web.json_response({'count': await async_run(COLLECTION.count)})


@routes.put('/api/v1/item')
async def edit_item(request: web.BaseRequest):
    data = await request.json()
    await async_run(
        COLLECTION.update,
        ids=[request.query.get('id')],
        metadatas=[data.get('metadata', {})],
        documents=[data.get('document', {})]
    )
    return


def run():
    global COLLECTION
    console = Console(color_system="standard", quiet=QUIET, width=180)
    logging.basicConfig(level="NOTSET", format="%(message)s", datefmt="[%X]", handlers=[
        RichHandler(console=console, enable_link_path=False)
    ])

    log.info("Loading collection: " + COLLECTION_NAME)
    sentence_transformer_ef = embedding_functions.InstructorEmbeddingFunction(
        model_name=MODEL_NAME, device=TORCH_DEVICE)
    client = chromadb.PersistentClient(
        path=DATABASE_DIR,
        settings=Settings(
            anonymized_telemetry=False,
        )
    )
    COLLECTION = client.get_or_create_collection(name=COLLECTION_NAME, embedding_function=sentence_transformer_ef)
    log.info(f"Using web root: {WEBDATA_DIR.absolute()}")
    app = web.Application(logger=log)
    app.add_routes(routes)
    app.router.add_static('/css', WEBDATA_DIR / 'css')
    app.router.add_static('/fonts', WEBDATA_DIR / 'fonts')
    app.router.add_static('/img', WEBDATA_DIR / 'img')
    app.router.add_static('/js', WEBDATA_DIR / 'js')

    log.info(f'Serving http at http://{HTTP_HOST}:{HTTP_PORT}')
    web.run_app(app, host=HTTP_HOST, port=HTTP_PORT, access_log=log,
                access_log_format='%a "%r" %s %b "%{Referer}i" "%{User-Agent}i"', print=False)


if __name__ == '__main__':
    run()