import json
import traceback

import sys
import os

SD_DIR = os.getcwd()
print('started in ', SD_DIR)

SD_UI_DIR = os.getenv('SD_UI_PATH', None)
sys.path.append(os.path.dirname(SD_UI_DIR))

CONFIG_DIR = os.path.abspath(os.path.join(SD_UI_DIR, '..', 'scripts'))
MODELS_DIR = os.path.abspath(os.path.join(SD_DIR, '..', 'models'))

OUTPUT_DIRNAME = "Stable Diffusion UI" # in the user's home folder
TASK_TTL = 15 * 60 # Discard last session's task timeout
APP_CONFIG_DEFAULTS = {
    # auto: selects the cuda device with the most free memory, cuda: use the currently active cuda device.
    'render_devices': ['auto'], # ['cuda'] or ['CPU', 'GPU:0', 'GPU:1', ...] or ['cpu']
    'update_branch': 'main',
}
APP_CONFIG_DEFAULT_MODELS = [
    # needed to support the legacy installations
    'custom-model', # Check if user has a custom model, use it first.
    'sd-v1-4', # Default fallback.
]

from fastapi import FastAPI, HTTPException
from fastapi.staticfiles import StaticFiles
from starlette.responses import FileResponse, JSONResponse, StreamingResponse
from pydantic import BaseModel
import logging
#import queue, threading, time
from typing import Any, Generator, Hashable, List, Optional, Union

from sd_internal import Request, Response, task_manager

app = FastAPI()

modifiers_cache = None
outpath = os.path.join(os.path.expanduser("~"), OUTPUT_DIRNAME)

# don't show access log entries for URLs that start with the given prefix
ACCESS_LOG_SUPPRESS_PATH_PREFIXES = ['/ping', '/image', '/modifier-thumbnails']

NOCACHE_HEADERS={"Cache-Control": "no-cache, no-store, must-revalidate", "Pragma": "no-cache", "Expires": "0"}
app.mount('/media', StaticFiles(directory=os.path.join(SD_UI_DIR, 'media/')), name="media")

config_cached = None
config_last_mod_time = 0
def getConfig(default_val=APP_CONFIG_DEFAULTS):
    global config_cached, config_last_mod_time
    try:
        config_json_path = os.path.join(CONFIG_DIR, 'config.json')
        if not os.path.exists(config_json_path):
            return default_val
        if config_last_mod_time > 0 and config_cached is not None:
            # Don't read if file was not modified
            mtime = os.path.getmtime(config_json_path)
            if mtime <= config_last_mod_time:
                return config_cached
        with open(config_json_path, 'r') as f:
            config_cached = json.load(f)
        config_last_mod_time = os.path.getmtime(config_json_path)
        return config_cached
    except Exception as e:
        print(str(e))
        print(traceback.format_exc())
        return default_val

def setConfig(config):
    try: # config.json
        config_json_path = os.path.join(CONFIG_DIR, 'config.json')
        with open(config_json_path, 'w') as f:
            return json.dump(config, f)
    except:
        print(traceback.format_exc())

    if 'render_devices' in config:
        gpu_devices = filter(lambda dev: dev.startswith('GPU:'), config['render_devices'])
    else:
        gpu_devices = []

    try: # config.bat
        config_bat = [
            f"@set update_branch={config['update_branch']}"
        ]
        if len(gpu_devices) > 0:
            config_sh.append(f"@set CUDA_VISIBLE_DEVICES={','.join(gpu_devices)}")
        config_bat_path = os.path.join(CONFIG_DIR, 'config.bat')
        with open(config_bat_path, 'w') as f:
            f.write(f.write('\r\n'.join(config_bat)))
    except Exception as e:
        print(traceback.format_exc())

    try: # config.sh
        config_sh = [
            '#!/bin/bash'
            f"export update_branch={config['update_branch']}"
        ]
        if len(gpu_devices) > 0:
            config_sh.append(f"CUDA_VISIBLE_DEVICES={','.join(gpu_devices)}")
        config_sh_path = os.path.join(CONFIG_DIR, 'config.sh')
        with open(config_sh_path, 'w') as f:
            f.write('\n'.join(config_sh))
    except Exception as e:
        print(traceback.format_exc())

def resolve_model_to_use(model_name:str=None):
    if not model_name: # When None try user configured model.
        config = getConfig()
        if 'model' in config and 'stable-diffusion' in config['model']:
            model_name = config['model']['stable-diffusion']
    if model_name:
        if os.path.exists(model_name + '.ckpt'):
            # Direct Path to file
            return model_name
        # Check models directory
        models_dir_path = os.path.join(MODELS_DIR, 'stable-diffusion', model_name)
        if os.path.exists(models_dir_path + '.ckpt'):
            return models_dir_path
    # Default locations
    if model_name in APP_CONFIG_DEFAULT_MODELS:
        default_model_path = os.path.join(SD_DIR, model_name)
        if os.path.exists(default_model_path + '.ckpt'):
            return default_model_path
    # Can't find requested model, check the default paths.
    for default_model in APP_CONFIG_DEFAULT_MODELS:
        default_model_path = os.path.join(SD_DIR, default_model + '.ckpt')
        if os.path.exists(default_model_path):
            print('Could not find the configured custom model at:', model_path + '.ckpt', '. Using the default one:', default_model_path + '.ckpt')
            return default_model_path
    raise Exception('No valid models found.')

class SetAppConfigRequest(BaseModel):
    update_branch: str = None
    render_devices: Union[List[str], List[int], str, int] = None

@app.post('/app_config')
async def setAppConfig(req : SetAppConfigRequest):
    config = getConfig()
    if req.update_branch:
        config['update_branch'] = req.update_branch
    if req.render_devices and hasattr(req.render_devices, "__len__"): # strings, array of strings or numbers.
        render_devices = []
        if isinstance(req.render_devices, str):
            req.render_devices = req.render_devices.split(',')
        if isinstance(req.render_devices, list):
            for gpu in req.render_devices:
                if isinstance(req.render_devices, int):
                    render_devices.append('GPU:' + gpu)
                else:
                    render_devices.append(gpu)
        if isinstance(req.render_devices, int):
            render_devices.append('GPU:' + req.render_devices)
        if len(render_devices) > 0:
            config['render_devices'] = render_devices
    try:
        setConfig(config)
        return JSONResponse({'status': 'OK'}, headers=NOCACHE_HEADERS)
    except Exception as e:
        print(traceback.format_exc())
        return HTTPException(status_code=500, detail=str(e))

def getModels():
    models = {
        'active': {
            'stable-diffusion': 'sd-v1-4',
        },
        'options': {
            'stable-diffusion': ['sd-v1-4'],
        },
    }

    # custom models
    sd_models_dir = os.path.join(MODELS_DIR, 'stable-diffusion')
    for file in os.listdir(sd_models_dir):
        if file.endswith('.ckpt'):
            model_name = os.path.splitext(file)[0]
            models['options']['stable-diffusion'].append(model_name)

    # legacy
    custom_weight_path = os.path.join(SD_DIR, 'custom-model.ckpt')
    if os.path.exists(custom_weight_path):
        models['active']['stable-diffusion'] = 'custom-model'
        models['options']['stable-diffusion'].append('custom-model')

    config = getConfig()
    if 'model' in config and 'stable-diffusion' in config['model']:
        models['active']['stable-diffusion'] = config['model']['stable-diffusion']

    return models

@app.get('/get/{key:path}')
def read_web_data(key:str=None):
    if not key: # /get without parameters, stable-diffusion easter egg.
        return HTTPException(status_code=418, detail="StableDiffusion is drawing a teapot!") # HTTP418 I'm a teapot
    elif key == 'app_config':
        config = getConfig(default_val=None)
        if config is None:
            return HTTPException(status_code=500, detail="Config file is missing or unreadable")
        return JSONResponse(config, headers=NOCACHE_HEADERS)
    elif key == 'models':
        return JSONResponse(getModels(), headers=NOCACHE_HEADERS)
    elif key == 'modifiers': return FileResponse(os.path.join(SD_UI_DIR, 'modifiers.json'), headers=NOCACHE_HEADERS)
    elif key == 'output_dir': return JSONResponse({ 'output_dir': outpath }, headers=NOCACHE_HEADERS)
    else:
        return HTTPException(status_code=404, detail=f'Request for unknown {key}') # HTTP404 Not Found

@app.get('/ping') # Get server and optionally session status.
def ping(session_id:str=None):
    if task_manager.is_alive() <= 0: # Check that render threads are alive.
        if task_manager.current_state_error: return HTTPException(status_code=500, detail=str(task_manager.current_state_error))
        return HTTPException(status_code=500, detail='Render thread is dead.')
    if task_manager.current_state_error and not isinstance(task_manager.current_state_error, StopAsyncIteration): return HTTPException(status_code=500, detail=str(task_manager.current_state_error))
    # Alive
    response = {'status': str(task_manager.current_state)}
    if session_id:
        task = task_manager.task_cache.tryGet(session_id)
        if task:
            response['task'] = id(task)
            if task.lock.locked():
                response['session'] = 'running'
            elif isinstance(task.error, StopAsyncIteration):
                response['session'] = 'stopped'
            elif task.error:
                response['session'] = 'error'
            elif not task.buffer_queue.empty():
                response['session'] = 'buffer'
            elif task.response:
                response['session'] = 'completed'
            else:
                response['session'] = 'pending'
    return JSONResponse(response, headers=NOCACHE_HEADERS)

def save_model_to_config(model_name):
    config = getConfig()
    if 'model' not in config:
        config['model'] = {}

    config['model']['stable-diffusion'] = model_name
    setConfig(config)

@app.post('/render')
def render(req : task_manager.ImageRequest):
    if req.use_cpu and task_manager.is_alive('cpu') <= 0: return HTTPException(status_code=403, detail=f'CPU rendering is not enabled in config.json or the thread has died...') # HTTP403 Forbidden
    if req.use_face_correction and task_manager.is_alive(0) <= 0 and task_manager.is_alive('cpu') <= 0: #TODO Remove when GFPGANer is fixed upstream.
        return HTTPException(status_code=412, detail=f'GFPGANer only works on CPU or GPU:0, use CUDA_VISIBLE_DEVICES if GFPGANer is needed on a specific GPU.') # HTTP412 Precondition Failed
    try:
        save_model_to_config(req.use_stable_diffusion_model)
        req.use_stable_diffusion_model = resolve_model_to_use(req.use_stable_diffusion_model)
        new_task = task_manager.render(req)
        response = {
            'status': str(task_manager.current_state), 
            'queue': len(task_manager.tasks_queue),
            'stream': f'/image/stream/{req.session_id}/{id(new_task)}',
            'task': id(new_task)
        }
        return JSONResponse(response, headers=NOCACHE_HEADERS)
    except ChildProcessError as e: # Render thread is dead
        return HTTPException(status_code=500, detail=f'Rendering thread has died.') # HTTP500 Internal Server Error
    except ConnectionRefusedError as e: # Unstarted task pending, deny queueing more than one.
        return HTTPException(status_code=503, detail=f'Session {req.session_id} has an already pending task.') # HTTP503 Service Unavailable
    except Exception as e:
        return HTTPException(status_code=500, detail=str(e))

@app.get('/image/stream/{session_id:str}/{task_id:int}')
def stream(session_id:str, task_id:int):
    #TODO Move to WebSockets ??
    task = task_manager.task_cache.tryGet(session_id)
    if not task: return HTTPException(status_code=410, detail='No request received.') # HTTP410 Gone
    if (id(task) != task_id): return HTTPException(status_code=409, detail=f'Wrong task id received. Expected:{id(task)}, Received:{task_id}') # HTTP409 Conflict
    if task.buffer_queue.empty() and not task.lock.locked():
        if task.response:
            #print(f'Session {session_id} sending cached response')
            return JSONResponse(task.response, headers=NOCACHE_HEADERS)
        return HTTPException(status_code=425, detail='Too Early, task not started yet.') # HTTP425 Too Early
    #print(f'Session {session_id} opened live render stream {id(task.buffer_queue)}')
    return StreamingResponse(task.read_buffer_generator(), media_type='application/json')

@app.get('/image/stop')
def stop(session_id:str=None):
    if not session_id:
        if task_manager.current_state == task_manager.ServerStates.Online or task_manager.current_state == task_manager.ServerStates.Unavailable:
            return HTTPException(status_code=409, detail='Not currently running any tasks.') # HTTP409 Conflict
        task_manager.current_state_error = StopAsyncIteration('')
        return {'OK'}
    task = task_manager.task_cache.tryGet(session_id)
    if not task: return HTTPException(status_code=404, detail=f'Session {session_id} has no active task.') # HTTP404 Not Found
    if isinstance(task.error, StopAsyncIteration): return HTTPException(status_code=409, detail=f'Session {session_id} task is already stopped.') # HTTP409 Conflict
    task.error = StopAsyncIteration('')
    return {'OK'}

@app.get('/image/tmp/{session_id}/{img_id:int}')
def get_image(session_id, img_id):
    task = task_manager.task_cache.tryGet(session_id)
    if not task: return HTTPException(status_code=410, detail=f'Session {session_id} has not submitted a task.') # HTTP410 Gone
    if not task.temp_images[img_id]: return HTTPException(status_code=425, detail='Too Early, task data is not available yet.') # HTTP425 Too Early
    try:
        img_data = task.temp_images[img_id]
        if isinstance(img_data, str):
            return img_data
        img_data.seek(0)
        return StreamingResponse(img_data, media_type='image/jpeg')
    except KeyError as e:
        return HTTPException(status_code=500, detail=str(e))

@app.get('/')
def read_root():
    return FileResponse(os.path.join(SD_UI_DIR, 'index.html'), headers=NOCACHE_HEADERS)

@app.on_event("shutdown")
def shutdown_event(): # Signal render thread to close on shutdown
    task_manager.current_state_error = SystemExit('Application shutting down.')

# don't log certain requests
class LogSuppressFilter(logging.Filter):
    def filter(self, record: logging.LogRecord) -> bool:
        path = record.getMessage()
        for prefix in ACCESS_LOG_SUPPRESS_PATH_PREFIXES:
            if path.find(prefix) != -1:
                return False
        return True
logging.getLogger('uvicorn.access').addFilter(LogSuppressFilter())

config = getConfig()
# Start the task_manager
task_manager.default_model_to_load = resolve_model_to_use()
if 'render_devices' in config: # Start a new thread for each device.
    if isinstance(config['render_devices'], str):
        config['render_devices'] = config['render_devices'].split(',')
    if not isinstance(config['render_devices'], list):
        raise Exception('Invalid render_devices value in config.')
    for device in config['render_devices']:
        task_manager.start_render_thread(device)

allow_cpu = False
if task_manager.is_alive() <= 0: # No running devices, apply defaults.
    # Select best device GPU device using free memory if more than one device.
    task_manager.start_render_thread('auto')
    allow_cpu = True

# Allow CPU to be used for renders if not already enabled in current config.
if task_manager.is_alive('cpu') <= 0 and allow_cpu:
    task_manager.start_render_thread('cpu')

# start the browser ui
import webbrowser; webbrowser.open('http://localhost:9000')