app.py

import io
import os
import base64
import json
import logging
import unicodedata
import tempfile
from difflib import SequenceMatcher
from PIL import Image, ImageDraw, ImageFont, ImageOps

import cv2
import numpy as np
import gradio as gr
from google.cloud import vision
from google.oauth2 import service_account
from kospellpy import spell_init

# ──────────────────────────────── 환경 설정 ────────────────────────────────
logging.basicConfig(level=logging.INFO, format='%(asctime)s %(levelname)s: %(message)s')
FONT_PATH = os.path.join(os.path.dirname(__file__), "NanumGothicCoding.ttf")
MIN_FONT_SIZE = 8

# GCP 서비스 계정 키 base64 → JSON 디코딩
def get_vision_client():
    b64 = os.getenv("GCP_SERVICE_ACCOUNT_JSON")
    if not b64:
        logging.warning("GCP_SERVICE_ACCOUNT_JSON 환경변수가 설정되지 않았습니다. 기본 인증을 사용합니다.")
        return vision.ImageAnnotatorClient()
    try:
        info = json.loads(base64.b64decode(b64).decode())
        creds = service_account.Credentials.from_service_account_info(info)
        return vision.ImageAnnotatorClient(credentials=creds)
    except Exception as e:
        logging.error(f"Vision API 인증 실패: {e}")
        raise

vision_client = get_vision_client()
checker = spell_init()

# ──────────────────────────────── 유틸 함수 ────────────────────────────────
def normalize_text(text: str) -> str:
    return unicodedata.normalize('NFC', text)

def compute_font_for_word(vertices):
    ys = [v.y for v in vertices]
    bbox_h = max(ys) - min(ys)
    size = max(MIN_FONT_SIZE, int(bbox_h * 0.4))
    try:
        return ImageFont.truetype(FONT_PATH, size)
    except Exception as e:
        print(f"[WARNING] 폰트 로딩 실패: {e}")
        return ImageFont.load_default()

def preprocess_with_adaptive_threshold(img: Image.Image) -> Image.Image:
    cv_img = cv2.cvtColor(np.array(img), cv2.COLOR_RGB2BGR)
    gray = cv2.cvtColor(cv_img, cv2.COLOR_BGR2GRAY)
    adap = cv2.adaptiveThreshold(gray, 255, cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY, 25, 10)
    bgr = cv2.cvtColor(adap, cv2.COLOR_GRAY2BGR)
    return Image.fromarray(cv2.cvtColor(bgr, cv2.COLOR_BGR2RGB))

# ──────────────────────────────── OCR 및 교정 ────────────────────────────────
def ocr_overlay_and_correct_text(img: Image.Image):
    corrected_text = ""
    overlay = None
    if img is not None:
        img = ImageOps.exif_transpose(img)
        proc = preprocess_with_adaptive_threshold(img)
        buf = io.BytesIO(); proc.save(buf, format='PNG')

        res = vision_client.document_text_detection(
            image=vision.Image(content=buf.getvalue()),
            image_context={'language_hints': ['ko']}
        )
        ann = res.full_text_annotation
        raw = ann.text.replace('\n', ' ').strip()
        logging.info(f"[OCR] Raw: {raw}")
        corrected_text = checker(raw)
        logging.info(f"[Spell] Corrected: {corrected_text}")

        syms = []
        for pg in ann.pages:
            for bl in pg.blocks:
                for para in bl.paragraphs:
                    for w in para.words:
                        for s in w.symbols:
                            syms.append({'text': normalize_text(s.text), 'bbox': s.bounding_box.vertices})

        raw_c, corr_c, mapping = list(raw), list(corrected_text), {}
        idx = 0
        for i, ch in enumerate(raw_c):
            if ch.strip():
                mapping[i] = idx
                idx += 1

        sm = SequenceMatcher(None, raw_c, corr_c)
        overlay = img.copy()
        draw = ImageDraw.Draw(overlay)
        col = "#FF3333"

        for tag, i1, i2, j1, j2 in sm.get_opcodes():
            if tag not in ('replace', 'insert'):
                continue
            repl = ''.join(corr_c[j1:j2])
            if tag == 'insert' and repl == ' ':
                repl = 'V'
            valid = (
                [k for k in range(i1, i2) if k in mapping]
                if tag == 'replace'
                else ([max(i1-1, 0)] if max(i1-1, 0) in mapping else [])
            )
            for k in valid:
                sd = mapping[k]
                verts = syms[sd]['bbox']
                xs, ys = [v.x for v in verts], [v.y for v in verts]
                x0, x1, y0, y1 = min(xs), max(xs), min(ys), max(ys)
                ul = y0 + int((y1 - y0) * 0.9)
                draw.line([(x0, ul), (x1, ul)], fill=col, width=3)
            if valid:
                sd = mapping[valid[0]]
                verts = syms[sd]['bbox']
                xs, ys = [v.x for v in verts], [v.y for v in verts]
                x0, x1, y0 = min(xs), max(xs), min(ys)
                if tag == 'insert' and len(repl) == 1 and not repl.isalnum():
                    prev_k = max(i1 - 1, 0)
                    if prev_k in mapping:
                        prev_sd = mapping[prev_k]
                        prev_verts = syms[prev_sd]['bbox']
                        prev_xs = [v.x for v in prev_verts]
                        fx = max(prev_xs + xs)
                        overlay_str = raw_c[prev_k] + repl
                    else:
                        overlay_str, fx = repl, x1
                elif repl == 'V':
                    overlay_str, fx = 'V', x1
                elif not repl.isalnum():
                    overlay_str, fx = repl, x1
                else:
                    overlay_str, fx = repl, x0
                fy = y0
                font = compute_font_for_word(verts)
                draw.text((fx, fy), overlay_str, font=font, fill=col)

    return overlay, corrected_text

# ──────────────────────────────── Gradio 핸들러 ────────────────────────────────
def text_correct_fn(text):
    raw = normalize_text(text.strip())
    corrected = checker(raw)
    return None, corrected

def img_correct_fn(blob):
    img = None
    if blob:
        img = Image.open(io.BytesIO(blob)).convert('RGB')
    return ocr_overlay_and_correct_text(img)

# ──────────────────────────────── Gradio UI ────────────────────────────────
with gr.Blocks(
    css="""
        .gradio-container {background-color: #fafaf5}
        footer {display: none !important;}
        .gr-box {border: 2px solid black !important;}
        * { font-family: 'Quicksand', ui-sans-serif, sans-serif !important; }
    """,
    theme="dark"
) as demo:
    state = gr.State()
    gr.Markdown("## 📷찰칵! 맞춤법 검사기")
    with gr.Row():
        with gr.Column():
            upload = gr.UploadButton(label='사진 촬영 및 업로드', file_types=['image'], type='binary')
            img_check_btn = gr.Button('✔️검사하기', interactive=False)
        with gr.Column():
            text_in = gr.Textbox(lines=3, placeholder='텍스트를 직접 입력하세요 (선택)', label='💻직접 입력 텍스트')
            text_check_btn = gr.Button('텍스트 검사', interactive=False)

    img_out = gr.Image(type='pil', label='교정 결과')
    txt_out = gr.Textbox(label='교정된 텍스트')
    clear_btn = gr.Button('초기화')

    def on_upload_start():
        return gr.update(label="업로드 중...", interactive=False), gr.update(interactive=False)
    upload.upload(on_upload_start, None, [upload, img_check_btn], queue=False, preprocess=False)

    def on_upload_complete(blob):
        return blob, gr.update(label="업로드 완료", interactive=False), gr.update(interactive=True)
    upload.upload(on_upload_complete, inputs=[upload], outputs=[state, upload, img_check_btn])

    def on_img_check(blob):
        result = img_correct_fn(blob)
        return gr.update(label="사진 촬영 및 업로드", interactive=True, value=None), gr.update(interactive=False), result[0], result[1]
    img_check_btn.click(on_img_check, inputs=[state], outputs=[upload, img_check_btn, img_out, txt_out])

    def enable_text_check(text):
        return gr.update(interactive=bool(text.strip()))
    text_in.change(enable_text_check, inputs=[text_in], outputs=[text_check_btn])

    text_check_btn.click(text_correct_fn, inputs=[text_in], outputs=[img_out, txt_out])

    def on_clear():
        return None, gr.update(label="사진 촬영 및 업로드", interactive=True, value=None), '', gr.update(interactive=False), None, ''
    clear_btn.click(on_clear, None, [state, upload, text_in, img_check_btn, img_out, txt_out])

# Hugging Face Spaces 전용 launch
if __name__ == '__main__':
    demo.launch(server_name="0.0.0.0", server_port=int(os.getenv("PORT", 7860)))