main.py

from fastapi import FastAPI, UploadFile
from fastapi.staticfiles import StaticFiles
from fastapi.responses import FileResponse

import subprocess
import os
import json
import uuid
import html

import torch
from diffusers import (
    StableDiffusionPipeline,
    DPMSolverMultistepScheduler,
    EulerDiscreteScheduler,
)

app = FastAPI()

def file_extension(filename):
  filename_list = filename.split(".")
  return filename_list[1].lower()


@app.get("/generate")
def generate_image(prompt, model):
    torch.cuda.empty_cache()

    prompt = html.escape(prompt)
    model = html.escape(model)

    modelArray = model.split(",")
    modelName = modelArray[0]
    modelVersion = modelArray[1]

    pipeline = StableDiffusionPipeline.from_pretrained(
        str(modelName), torch_dtype=torch.float16
    )
    pipeline.scheduler = EulerDiscreteScheduler.from_config(pipeline.scheduler.config)
    pipeline = pipeline.to("cuda")

    image = pipeline(prompt, num_inference_steps=50, height=512, width=512).images[0]

    filename = str(uuid.uuid4()) + ".jpg"
    image.save(filename)

    assertion = {
       "assertions": [
           {
               "label": "com.truepic.custom.ai",
               "data": {
                   "model_name": modelName,
                   "model_version": modelVersion,
                   "prompt": prompt,
               },
           }
       ]
    }

    json_object = json.dumps(assertion)

    subprocess.check_output(
        [
            "./scripts/sign.sh",
            filename,
            filename,
            "--assertions-inline",
            json_object
        ]
    )

    subprocess.check_output(
        [
            "cp",
            filename,
            "static/" + filename,
        ]
    )

    return {"response": filename}


@app.post("/verify")
def verify_image(fileUpload: UploadFile):
    # check if the file has been uploaded
    if fileUpload.filename:
        fileupload_extension = file_extension(fileUpload.filename)
        input_filename = str(uuid.uuid4()) + "." + fileupload_extension
        output_filename = str(uuid.uuid4()) + "." + fileupload_extension

        # strip the leading path from the file name
        fn = os.path.basename(input_filename)

        # open read and write the file into the server
        open(fn, "wb").write(fileUpload.file.read())

        
        response = subprocess.check_output(
            [
                "./scripts/verify.sh",
                input_filename,
                output_filename
            ]
        )
     
        response_list = response.splitlines()
        
        c2pa_string = str(response_list[0])
        c2pa = c2pa_string.split(":", 1)
        c2pa = c2pa[1].strip(" ").strip("'")

        watermark_string = str(response_list[1])
        watermark = watermark_string.split(":", 1)
        watermark = watermark[1].strip(" ").strip("'")

        original_media_string = str(response_list[2])
        original_media = original_media_string.split(":", 1)
        original_media = original_media[1].strip(" ").strip("'")

        if c2pa == 'true':
            response = subprocess.check_output(
                [
                    "cp",
                    input_filename,
                    "static/" + output_filename,
                ]
            )

            result_media = output_filename

        elif original_media != 'n/a':
            original_media_extension = file_extension(original_media)
            filename = str(uuid.uuid4()) + "." + original_media_extension
            
            response = subprocess.check_output(
                [
                    "cp",
                    original_media,
                    "static/" + filename,
                ]
            ) 

            result_media = filename
        else:
            result_media = 'n/a'


    return {"response": fileUpload.filename, "contains_c2pa" : c2pa, "contains_watermark" : watermark, "result_media" : result_media}



app.mount("/", StaticFiles(directory="static", html=True), name="static")


@app.get("/")
def index() -> FileResponse:
    return FileResponse(path="/app/static/index.html", media_type="text/html")