import gradio as gr
import sqlite3
import pandas as pd
import os
import re
import base64
import difflib
import traceback

# ==========================================
# 1. Environment Setup & Data Helpers
# ==========================================
UPLOAD_DIR = "uploaded_dbs"
if not os.path.exists(UPLOAD_DIR):
    os.makedirs(UPLOAD_DIR)

db_registry = []

def convert_blob_to_html_img(blob_data):
    if blob_data is None or pd.isna(blob_data):
        return ""
    try:
        if isinstance(blob_data, (bytes, bytearray)):
            encoded = base64.b64encode(blob_data).decode('utf-8')
            return f'''
            <img src="data:image/png;base64,{encoded}"
                 style="width: 40%; 
                        max-height: 300px; 
                        object-fit: contain;
                        display: block;
                        margin: 10px 0;">
            '''
        return str(blob_data)
    except Exception:
        return str(blob_data)

def decode_sqlite_text(x):
    try:
        return x.decode('utf-8')
    except UnicodeDecodeError:
        return x

def fetch_available_standards():
    global db_registry
    db_registry = []

    for file_name in os.listdir(UPLOAD_DIR):
        if file_name.endswith(".db"):
            name = file_name.replace(".db", "")
            parts = name.split("_")
            if len(parts) >= 2:
                db_registry.append({
                    "path": os.path.join(UPLOAD_DIR, file_name),
                    "standard": parts[0],
                    "version": parts[1]
                })

    return sorted(list(set([d["standard"] for d in db_registry])))


# ==========================================
# 2. UI Component Handlers
# ==========================================

def load_initial_standards():
    return gr.Dropdown(choices=fetch_available_standards())

def update_version_dropdown(standard):
    if not standard:
        return gr.Dropdown(choices=[])
    versions = sorted(set(d["version"] for d in db_registry if d["standard"] == standard))
    return gr.Dropdown(choices=versions)

# ⬇️ [수정] Version이 선택되면 Category와 함께 Status 값도 같이 리턴합니다.
def update_base_category_dropdown(standard, version):
    if not standard or not version:
        return gr.update(choices=[], value=None, interactive=False), gr.update(value="")

    choices = ["ALL"]
    status_value = "" # Status 기본값
    
    db_path = os.path.join(UPLOAD_DIR, f"{standard}_{version}.db")
    if not os.path.exists(db_path): 
        return gr.update(choices=choices), gr.update(value="")

    try:
        conn = sqlite3.connect(db_path)
        tables = pd.read_sql("SELECT name FROM sqlite_master WHERE type='table';", conn)['name'].tolist()
        
        valid_tables = [t for t in tables if t.lower() not in ['mapping_registry', 'mapping_table', 'table_config', 'sqlite_sequence']]
        
        main_table = f"{standard}_{version}"
        if main_table not in valid_tables:
            main_table = valid_tables[0] if valid_tables else None

        if main_table:
            # 💡 [핵심 추가] DB에서 Status 값을 읽어옵니다.
            try:
                cols_check = pd.read_sql(f"PRAGMA table_info([{main_table}])", conn)['name'].tolist()
                if "Status" in cols_check or "status" in cols_check:
                    status_df = pd.read_sql(f"SELECT Status FROM [{main_table}] WHERE Status IS NOT NULL AND Status != '' LIMIT 1", conn)
                    if not status_df.empty:
                        status_value = str(status_df.iloc[0]['Status'])
            except Exception:
                pass

            cols = pd.read_sql(f"PRAGMA table_info([{main_table}])", conn)['name'].tolist()
            lower_cols = [c.lower() for c in cols]
            if 'chapter' in lower_cols and 'category' in lower_cols:
                ch_col = cols[lower_cols.index('chapter')]
                ca_col = cols[lower_cols.index('category')]
                
                df = pd.read_sql(f"SELECT DISTINCT [{ch_col}], [{ca_col}] FROM [{main_table}]", conn)
                for _, row in df.iterrows():
                    ch = str(row[ch_col]).strip()
                    ca = str(row[ca_col]).strip()
                    if ch and ca and ch.lower() not in ['none', 'nan'] and ca.lower() not in ['none', 'nan']:
                        choices.append(f"{ch}.{ca}")

        pattern = re.compile(f"^{standard}[_\\s-]*{version}[_\\s-]*", re.IGNORECASE)
        for t in valid_tables:
            if t == main_table: continue
            short_name = pattern.sub("", t).strip(" _")
            if short_name and short_name not in choices:
                choices.append(short_name)
            elif t not in choices:
                choices.append(t)

        conn.close()
    except Exception: 
        import traceback
        traceback.print_exc()
        
    return gr.update(choices=choices, value=None, interactive=True), gr.update(value=status_value)

def update_comp_standard_dropdown(base_std, base_ver):
    if not base_std or not base_ver:
        return gr.Dropdown(choices=[], value=None, interactive=False)

    try:
        conn = sqlite3.connect(os.path.join(UPLOAD_DIR, "mapping.db"))
        query = "SELECT DISTINCT TRIM(Comp_std) AS Comp_std FROM Mapping_registry WHERE TRIM(Base_std)=TRIM(?) AND TRIM(Base_ver)=TRIM(?)"
        df = pd.read_sql(query, conn, params=[base_std, base_ver])
        conn.close()

        mapped_stds = sorted(df['Comp_std'].dropna().unique().tolist()) if not df.empty else []
        return gr.update(choices=mapped_stds, value=None, interactive=bool(mapped_stds))
    except Exception:
        return gr.update(choices=[], value=None, interactive=False)

def update_comp_version_dropdown(base_std, base_ver, comp_std):
    if not all([base_std, base_ver, comp_std]):
        return gr.update(choices=[], value=None, interactive=False)

    try:
        conn = sqlite3.connect(os.path.join(UPLOAD_DIR, "mapping.db"))
        query = "SELECT DISTINCT TRIM(Comp_ver) AS Comp_ver FROM Mapping_registry WHERE TRIM(Base_std)=TRIM(?) AND TRIM(Base_ver)=TRIM(?) AND TRIM(Comp_std)=TRIM(?)"
        df = pd.read_sql(query, conn, params=[base_std, base_ver, comp_std])
        conn.close()

        mapped_vers = sorted(df['Comp_ver'].dropna().unique().tolist()) if not df.empty else []
        return gr.update(choices=mapped_vers, value=None, interactive=bool(mapped_vers))
    except Exception:
        return gr.update(choices=[], value=None, interactive=False)

# ⬇️ [수정] 비교 법규에서도 Category 갱신 시 Status를 읽어옵니다.
def update_comp_category_dropdown(base_std, base_ver, base_cat, comp_std, comp_ver):
    if not all([base_std, base_ver, base_cat, comp_std, comp_ver]):
        return gr.update(choices=[], value=None, interactive=False), gr.update(value="")

    base_type = "Main" if not base_cat or base_cat == "ALL" or "." in base_cat else base_cat
    status_value = ""

    try:
        # Status 읽기
        comp_db_path = os.path.join(UPLOAD_DIR, f"{comp_std}_{comp_ver}.db")
        if os.path.exists(comp_db_path):
            c_conn = sqlite3.connect(comp_db_path)
            c_tables = pd.read_sql("SELECT name FROM sqlite_master WHERE type='table';", c_conn)['name'].tolist()
            c_valid_tables = [t for t in c_tables if t.lower() not in ['mapping_registry', 'mapping_table', 'table_config', 'sqlite_sequence']]
            c_main_table = f"{comp_std}_{comp_ver}"
            if c_main_table not in c_valid_tables:
                c_main_table = c_valid_tables[0] if c_valid_tables else None
            
            if c_main_table:
                try:
                    cols_check = pd.read_sql(f"PRAGMA table_info([{c_main_table}])", c_conn)['name'].tolist()
                    if "Status" in cols_check or "status" in cols_check:
                        status_df = pd.read_sql(f"SELECT Status FROM [{c_main_table}] WHERE Status IS NOT NULL AND Status != '' LIMIT 1", c_conn)
                        if not status_df.empty:
                            status_value = str(status_df.iloc[0]['Status'])
                except Exception:
                    pass

        conn = sqlite3.connect(os.path.join(UPLOAD_DIR, "mapping.db"))
        query = """
        SELECT DISTINCT TRIM(Comp_Type) AS Comp_Type 
        FROM Mapping_registry 
        WHERE TRIM(Base_std)=TRIM(?) 
          AND TRIM(Base_ver)=TRIM(?) 
          AND TRIM(Base_Type)=TRIM(?) 
          AND TRIM(Comp_std)=TRIM(?) 
          AND TRIM(Comp_ver)=TRIM(?)
        """
        df = pd.read_sql(query, conn, params=[base_std, base_ver, base_type, comp_std, comp_ver])
        conn.close()

        allowed_types = df['Comp_Type'].dropna().tolist()
        if not allowed_types:
            return gr.update(choices=[], value=None), gr.update(value=status_value)

        final_choices = []
        if "Main" in allowed_types:
            final_choices.append("ALL")
            if os.path.exists(comp_db_path):
                # c_conn is already closed above, reopen if needed
                c_conn = sqlite3.connect(comp_db_path)
                if c_main_table:
                    cols = pd.read_sql(f"PRAGMA table_info([{c_main_table}])", c_conn)['name'].tolist()
                    lower_cols = [c.lower() for c in cols]
                    if 'chapter' in lower_cols and 'category' in lower_cols:
                        ch_col = cols[lower_cols.index('chapter')]
                        ca_col = cols[lower_cols.index('category')]
                        
                        c_df = pd.read_sql(f"SELECT DISTINCT [{ch_col}], [{ca_col}] FROM [{c_main_table}]", c_conn)
                        for _, row in c_df.iterrows():
                            ch = str(row[ch_col]).strip()
                            ca = str(row[ca_col]).strip()
                            if ch and ca and ch.lower() not in ['none', 'nan'] and ca.lower() not in ['none', 'nan']:
                                final_choices.append(f"{ch}.{ca}")
                c_conn.close()
        
        for t in allowed_types:
            if t != "Main": final_choices.append(t)

        return gr.update(choices=final_choices, value=final_choices[0] if final_choices else None, interactive=True), gr.update(value=status_value)
        
    except Exception as e:
        import traceback
        traceback.print_exc()
        return gr.update(choices=[], value=None), gr.update(value="")

def reset_base_selections():
    # Status까지 4개를 리셋
    return gr.update(value=None), gr.update(choices=[], value=None), gr.update(choices=[], value=None), gr.update(value="")

def reset_comp_selections():
    # Status까지 4개를 리셋
    return gr.update(value=None), gr.update(choices=[], value=None), gr.update(choices=[], value=None), gr.update(value="")


# ==========================================
# 3. Core Logic & Data Processing
# ==========================================
def generate_html_diff(base_text, comp_text):
    base_text = "" if pd.isna(base_text) else str(base_text)
    comp_text = "" if pd.isna(comp_text) else str(comp_text)

    b_words = base_text.split()
    c_words = comp_text.split()

    diff_generator = list(difflib.ndiff(b_words, c_words))
    b_result, c_result = [], []
    i = 0

    while i < len(diff_generator):
        code = diff_generator[i][0]
        word = diff_generator[i][2:]

        if code == ' ':
            b_result.append(word)
            c_result.append(word)
        elif code == '-' and i+1 < len(diff_generator) and diff_generator[i+1][0] == '+':
            new_word = diff_generator[i+1][2:]
            b_result.append(f"<span style='color:#ff4d4f;font-weight:600'>{word}</span>")
            c_result.append(f"<span style='color:#ff4d4f;font-weight:600'>{new_word}</span>")
            i += 1
        elif code == '-':
            b_result.append(f"<span style='color:#ff4d4f;font-weight:600'>{word}</span>")
        elif code == '+':
            c_result.append(f"<span style='color:#2ecc71;font-weight:600'>{word}</span>")

        i += 1

    return " ".join(b_result), " ".join(c_result)

def fetch_database_records(standard, version, selection, table_type):
    if not all([standard, version, selection]):
        return pd.DataFrame({"Info": ["선택 필요"]}), []

    try:
        db_path = os.path.join(UPLOAD_DIR, f"{standard}_{version}.db")
        if not os.path.exists(db_path):
            return pd.DataFrame({"Error": [f"파일을 찾을 수 없습니다: {db_path}"]}), []
            
        conn = sqlite3.connect(db_path)
        conn.text_factory = decode_sqlite_text 

        tables = pd.read_sql("SELECT name FROM sqlite_master WHERE type='table';", conn)['name'].tolist()
        valid_tables = [t for t in tables if t.lower() not in ['mapping_registry', 'mapping_table', 'table_config', 'sqlite_sequence']]
        
        main_table = f"{standard}_{version}"
        if main_table not in valid_tables:
            main_table = valid_tables[0] if valid_tables else None

        target_table = None
        pattern = re.compile(f"^{standard}[_\\s-]*{version}[_\\s-]*", re.IGNORECASE)

        for t in valid_tables:
            if t == selection or pattern.sub("", t).strip(" _") == selection:
                target_table = t
                break

        if target_table and target_table != main_table:
            df = pd.read_sql(f"SELECT * FROM [{target_table}]", conn)
        else:
            if not main_table:
                return pd.DataFrame({"Error": ["데이터베이스 내에서 메인 테이블을 찾을 수 없습니다."]}), []
                
            cursor = conn.cursor()
            cursor.execute(f"PRAGMA table_info([{main_table}])")
            cols = [c[1] for c in cursor.fetchall()]
            lower_cols = [c.lower().strip() for c in cols]

            real_ch, real_cat = None, None
            for c, lc in zip(cols, lower_cols):
                if lc == "chapter": real_ch = c
                elif lc == "category": real_cat = c

            if selection == "ALL":
                cursor.execute(f"SELECT * FROM [{main_table}]")
            elif "." in selection and real_ch and real_cat:
                ch, ca = selection.split(".", 1)
                query = f"SELECT * FROM [{main_table}] WHERE REPLACE(TRIM(CAST([{real_ch}] AS TEXT)), ' ', '') = ? AND REPLACE(TRIM(CAST([{real_cat}] AS TEXT)), ' ', '') = ?"
                cursor.execute(query, (ch.replace(" ", ""), ca.replace(" ", "")))
            else:
                cursor.execute(f"SELECT * FROM [{main_table}]")
            
            df = pd.DataFrame(cursor.fetchall(), columns=cols)

        df = df.drop(columns=[c for c in df.columns if c.lower() == "version"], errors="ignore")
        
        # =========================================================
        # 💡 [스마트 스캔 로직] DB 컬럼을 보고 맞는 Main 설정을 알아서 찾습니다.
        # =========================================================
        conn_map = sqlite3.connect(os.path.join(UPLOAD_DIR, "mapping.db"))
        config_df = pd.read_sql("SELECT Anchor_Column, Display_Columns FROM Table_Config WHERE Table_Type=?", conn_map, params=[table_type])
        conn_map.close()

        anchor_col_config = "Section"
        display_setting = "Description"

        if not config_df.empty:
            df_cols_lower = [c.lower() for c in df.columns]
            for _, row in config_df.iterrows():
                # DB에 적힌 Anchor 열이 실제 데이터프레임에 존재하는지 확인
                first_anchor = str(row['Anchor_Column']).split(',')[0].strip().lower()
                if first_anchor in df_cols_lower:
                    anchor_col_config = str(row['Anchor_Column'])
                    raw_disp = row['Display_Columns']
                    display_setting = str(raw_disp) if pd.notna(raw_disp) and str(raw_disp).strip() != "" else None
                    break
        # =========================================================

        anchor_cols_config = [x.strip() for x in anchor_col_config.split(',')]

        real_anchors = []
        for ac in anchor_cols_config:
            real_ac = next((c for c in df.columns if c.lower() == ac.lower()), ac)
            real_anchors.append(real_ac)

        if display_setting:
            cols_to_show = [c.strip() for c in display_setting.split(',')]
            actual_cols_to_show = [c for c in df.columns if next((True for req in cols_to_show if c.lower() == req.lower()), False)]
            
            for ra in reversed(real_anchors):
                if ra in df.columns and ra not in actual_cols_to_show:
                    actual_cols_to_show.insert(0, ra)
            
            if actual_cols_to_show:
                df = df[actual_cols_to_show]

        for col in df.columns:
            df[col] = df[col].apply(convert_blob_to_html_img)

        return df, real_anchors 

    except Exception as e:
        import traceback
        traceback.print_exc()
        return pd.DataFrame({"Error": [str(e)]}), []

def execute_unified_search(base_std, base_ver, base_cat, comp_std, comp_ver, comp_cat, mapped_only, diff_only):
    try:
        def get_type_by_cat(cat):
            if not cat or cat == "ALL": return "Main"
            if "." in cat: return "Main"
            return cat

        type_b = get_type_by_cat(base_cat)
        type_c = get_type_by_cat(comp_cat)
        
        def apply_visual_merge(df, cols):
            if not df.empty and len(cols) > 1:
                is_dup = pd.Series([True] * len(df), index=df.index)
                for col in cols:
                    if col in df.columns:
                        curr = df[col].astype(str).str.strip()
                        match = (curr == curr.shift(1)) & (~curr.isin(["", "nan", "None", "&nbsp;"]))
                        is_dup = is_dup & match
                        df.loc[is_dup, col] = "&nbsp;"
            return df

        def combine_code_desc(df):
            cols = list(df.columns)
            new_cols = []
            processed = set()
            for col in cols:
                if col in processed: continue
                if "_Code" in col:
                    desc_col = col.replace("_Code", "_Description")
                    if desc_col in cols:
                        new_col_name = col.replace("_Code", "")
                        def combine_cells(row):
                            c, d = str(row[col]).strip(), str(row[desc_col]).strip()
                            if c in ["nan", "None", "", "&nbsp;"]: return d
                            if d in ["nan", "None", "", "&nbsp;"]: return f"<span style='font-weight:bold; color:#1a73e8;'>{c}</span>"
                            return f"<span style='font-weight:bold; color:#1a73e8; display:block; margin-bottom:4px;'>{c}</span>{d}"
                        df[new_col_name] = df.apply(combine_cells, axis=1)
                        new_cols.append(new_col_name)
                        processed.update([col, desc_col])
                    else: new_cols.append(col)
                elif "_Description" in col:
                    if col.replace("_Description", "_Code") not in cols: new_cols.append(col)
                else: new_cols.append(col)
            return df[new_cols]

        if base_std and base_ver and base_cat and (not comp_std or not comp_ver or not comp_cat):
            df, _ = fetch_database_records(base_std, base_ver, base_cat, type_b)
            if "Error" in df.columns: return df
            return apply_visual_merge(df, df.columns)

        if all([base_std, base_ver, base_cat, comp_std, comp_ver, comp_cat]):
            df_base, real_anchors_b = fetch_database_records(base_std, base_ver, base_cat, type_b)
            df_comp, real_anchors_c = fetch_database_records(comp_std, comp_ver, comp_cat, type_c)

            if "Error" in df_base.columns: return df_base
            if "Error" in df_comp.columns: return df_comp

            for ra in real_anchors_b:
                if ra not in df_base.columns: 
                    return pd.DataFrame({"Error": [f"기준 열(Anchor) '{ra}'이(가) 기준 데이터에 존재하지 않습니다. Table_Config를 확인하세요."]})
            for ra in real_anchors_c:
                if ra not in df_comp.columns: 
                    return pd.DataFrame({"Error": [f"비교 열(Anchor) '{ra}'이(가) 비교 데이터에 존재하지 않습니다. Table_Config를 확인하세요."]})

            def clean_key_val(v):
                s = str(v).strip()
                if s.endswith('.0') and s[:-2].isdigit(): 
                    s = s[:-2]
                return s.replace(" ", "")

            df_base['merge_key'] = df_base[real_anchors_b].apply(lambda row: '-'.join([clean_key_val(x) for x in row]), axis=1)
            df_comp['merge_key'] = df_comp[real_anchors_c].apply(lambda row: '-'.join([clean_key_val(x) for x in row]), axis=1)

            conn_map = sqlite3.connect(os.path.join(UPLOAD_DIR, "mapping.db"))
            
            q_fw = "SELECT * FROM Mapping_table WHERE TRIM(Base_std)=? AND TRIM(Base_ver)=? AND TRIM(Comp_std)=? AND TRIM(Comp_ver)=?"
            df_fw = pd.read_sql(q_fw, conn_map, params=[base_std.strip(), base_ver.strip(), comp_std.strip(), comp_ver.strip()])
            
            q_rv = "SELECT * FROM Mapping_table WHERE TRIM(Comp_std)=? AND TRIM(Comp_ver)=? AND TRIM(Base_std)=? AND TRIM(Base_ver)=?"
            df_rv = pd.read_sql(q_rv, conn_map, params=[base_std.strip(), base_ver.strip(), comp_std.strip(), comp_ver.strip()])
            conn_map.close()

            cols_fw_lower = {c.lower(): c for c in df_fw.columns}
            
            if 'base_type' in cols_fw_lower and 'comp_type' in cols_fw_lower:
                b_col = cols_fw_lower['base_type']
                c_col = cols_fw_lower['comp_type']
                
                df_fw[b_col] = df_fw[b_col].fillna('Main').astype(str).str.strip().str.upper()
                df_fw[c_col] = df_fw[c_col].fillna('Main').astype(str).str.strip().str.upper()
                df_fw = df_fw[(df_fw[b_col] == type_b.strip().upper()) & (df_fw[c_col] == type_c.strip().upper())]
                
                if not df_rv.empty:
                    df_rv[b_col] = df_rv[b_col].fillna('Main').astype(str).str.strip().str.upper()
                    df_rv[c_col] = df_rv[c_col].fillna('Main').astype(str).str.strip().str.upper()
                    df_rv = df_rv[(df_rv[c_col] == type_b.strip().upper()) & (df_rv[b_col] == type_c.strip().upper())]

            b_sec = cols_fw_lower.get('base_section', 'Base_section')
            c_sec = cols_fw_lower.get('comp_section', 'Comp_section')
            
            df_fw = df_fw[[b_sec, c_sec]].rename(columns={b_sec: 'Base_section', c_sec: 'Comp_section'})
            if not df_rv.empty:
                df_rv = df_rv[[b_sec, c_sec]].rename(columns={b_sec: 'Comp_section', c_sec: 'Base_section'})
            else:
                df_rv = pd.DataFrame(columns=['Base_section', 'Comp_section'])

            df_mapping = pd.concat([df_fw, df_rv], ignore_index=True)

            if not df_mapping.empty:
                df_mapping['Base_section'] = df_mapping['Base_section'].astype(str).str.replace('\n', ',').str.split(',')
                df_mapping['Comp_section'] = df_mapping['Comp_section'].astype(str).str.replace('\n', ',').str.split(',')
                df_mapping = df_mapping.explode('Base_section').explode('Comp_section')
                
                df_mapping['Base_section'] = df_mapping['Base_section'].apply(clean_key_val)
                df_mapping['Comp_section'] = df_mapping['Comp_section'].apply(clean_key_val)
                df_mapping = df_mapping.dropna().drop_duplicates()
            else:
                df_mapping = pd.DataFrame(columns=['Base_section', 'Comp_section'])

            if base_std.strip().upper() == comp_std.strip().upper() and type_b.strip().upper() == type_c.strip().upper():
                implicit = pd.DataFrame({'Base_section': list(set(df_base['merge_key']) & set(df_comp['merge_key'])), 
                                         'Comp_section': list(set(df_base['merge_key']) & set(df_comp['merge_key']))})
                bridge = pd.concat([df_mapping, implicit], ignore_index=True).drop_duplicates()
            else:
                bridge = df_mapping.copy()

            rename_b = {c: f"{c}_{base_ver}" for c in df_base.columns if c != 'merge_key'}
            df_base = df_base.rename(columns=rename_b)
            
            rename_c = {c: f"{c}_{comp_ver}" for c in df_comp.columns if c != 'merge_key'}
            df_comp = df_comp.rename(columns=rename_c)

            df_base['base_idx'], df_comp['comp_idx'] = range(len(df_base)), range(len(df_comp))
            merged = pd.merge(bridge, df_base, left_on='Base_section', right_on='merge_key', how='outer')
            merged = pd.merge(merged, df_comp, left_on='Comp_section', right_on='merge_key', how='outer')
            
            merged['base_idx'] = merged['base_idx'].fillna(float('inf'))
            merged['comp_idx'] = merged['comp_idx'].fillna(float('inf'))
            merged = merged.sort_values(['base_idx', 'comp_idx'])

            result_rows = []
            for _, row in merged.iterrows():
                row_dict = {}
                has_b = not pd.isna(row.get('base_idx')) and row.get('base_idx') != float('inf')
                has_c = not pd.isna(row.get('comp_idx')) and row.get('comp_idx') != float('inf')

                if mapped_only and not (has_b and has_c):
                    continue
                
                for c in rename_b.values(): row_dict[c] = str(row[c]) if has_b and not pd.isna(row[c]) else ""
                for c in rename_c.values(): row_dict[c] = str(row[c]) if has_c and not pd.isna(row[c]) else ""
                
                if has_b and has_c:
                    for orig_col in rename_b.keys():
                        if 'description' in orig_col.lower() and rename_c.get(orig_col) in row_dict:
                            b_v, c_v = row_dict[rename_b[orig_col]], row_dict[rename_c[orig_col]]
                            if b_v and c_v and "<img" not in b_v and "<img" not in c_v and b_v != c_v:
                                row_dict[rename_b[orig_col]], row_dict[rename_c[orig_col]] = generate_html_diff(b_v, c_v)
                result_rows.append(row_dict)

            final_df = combine_code_desc(pd.DataFrame(result_rows))

            if diff_only:
                mask = final_df.astype(str).apply(lambda col: col.str.contains('color:#ff4d4f|color:#2ecc71', case=False, regex=True)).any(axis=1)
                final_df = final_df[mask]
            
            b_cols_final = [c for c in final_df.columns if c.endswith(f"_{base_ver}")]
            c_cols_final = [c for c in final_df.columns if c.endswith(f"_{comp_ver}")]

            final_df = apply_visual_merge(final_df, b_cols_final)
            final_df = apply_visual_merge(final_df, c_cols_final)

            return final_df

        return pd.DataFrame({"Info": ["조건을 선택하세요."]})
    except Exception as e:
        import traceback
        traceback.print_exc()
        return pd.DataFrame({"Error": [f"시스템 오류 발생: {str(e)}"]})


# ==========================================
# 4. UI Layout & Event Binding
# ==========================================
with gr.Blocks() as demo:
    gr.Markdown("# 📜 Regulation Viewer")

    with gr.Row():
        with gr.Accordion("📌 기준 법규", open=True):
            with gr.Column():
                base_standard = gr.Dropdown(label="Standard")
                base_version = gr.Dropdown(label="Version")
                base_status = gr.Textbox(label="Status", interactive=False, lines=1)
                
                with gr.Row(elem_classes="reset-row"):
                    base_category = gr.Dropdown(label="Category", scale=4)
                    # ⬇️ elem_classes="reset-btn" 추가!
                    base_reset_btn = gr.Button("↺ 초기화", scale=1, elem_classes="reset-btn")
    
        with gr.Accordion("🔄 비교 법규", open=False):
            with gr.Column():
                comp_standard = gr.Dropdown(label="Standard", choices=[])
                comp_version = gr.Dropdown(label="Version", choices=[])
                comp_status = gr.Textbox(label="Status", interactive=False, lines=1)
                
                with gr.Row(elem_classes="reset-row"):
                    comp_category = gr.Dropdown(label="Category", choices=[], scale=4)
                    # ⬇️ elem_classes="reset-btn" 추가!
                    comp_reset_btn = gr.Button("↺ 초기화", scale=1, elem_classes="reset-btn")

    with gr.Row(elem_id="search_row"):
        search_btn = gr.Button("🔍 조회", variant="primary", scale=10)
        # ⬇️ [추가] 매핑 체크박스 추가!
        mapped_only_cb = gr.Checkbox(label="🔗 매핑된 항목만 보기", value=False, elem_id="mapped_cb_item", container=False, scale=1)
        diff_filter_cb = gr.Checkbox(label="💡 변경된 내용만 보기", value=False, elem_id="diff_cb_item", container=False, scale=1)

    output_df = gr.Dataframe(wrap=True, interactive=False, datatype="html", max_height=800)

    demo.load(fn=load_initial_standards, inputs=None, outputs=base_standard)

    base_standard.change(fn=update_version_dropdown, inputs=[base_standard], outputs=[base_version])
    base_version.change(fn=update_base_category_dropdown, inputs=[base_standard, base_version], outputs=[base_category, base_status])

    base_version.change(fn=update_comp_standard_dropdown, inputs=[base_standard, base_version], outputs=[comp_standard])
    comp_standard.change(fn=update_comp_version_dropdown, inputs=[base_standard, base_version, comp_standard], outputs=[comp_version])

    comp_change_triggers = [base_standard, base_version, base_category, comp_standard, comp_version]
    
    base_category.change(fn=update_comp_category_dropdown, inputs=comp_change_triggers, outputs=[comp_category, comp_status])
    comp_version.change(fn=update_comp_category_dropdown, inputs=comp_change_triggers, outputs=[comp_category, comp_status])

    search_btn.click(
        fn=execute_unified_search,
        inputs=[base_standard, base_version, base_category, comp_standard, comp_version, comp_category, mapped_only_cb, diff_filter_cb],
        outputs=[output_df]
    )
  
    mapped_only_cb.change(
        fn=execute_unified_search,
        inputs=[base_standard, base_version, base_category, comp_standard, comp_version, comp_category, mapped_only_cb, diff_filter_cb],
        outputs=[output_df]
    )

    diff_filter_cb.change(
        fn=execute_unified_search,
        inputs=[base_standard, base_version, base_category, comp_standard, comp_version, comp_category, mapped_only_cb, diff_filter_cb],
        outputs=[output_df]
    )

    base_reset_btn.click(fn=reset_base_selections, inputs=None, outputs=[base_standard, base_version, base_category, base_status])
    comp_reset_btn.click(fn=reset_comp_selections, inputs=None, outputs=[comp_standard, comp_version, comp_category, comp_status])


# ==========================================
# 5. Application Styling (CSS)
# ==========================================
css = """
.reset-row {
    align-items: flex-end !important; 
    margin-bottom: 5px !important; 
}
.reset-btn {
    margin-bottom: 10px !important; 
}

table { 
    table-layout: auto !important; 
    width: max-content !important; 
    min-width: 100% !important;
}

th, td {
    min-width: 150px; 
}

table:has(th:nth-last-child(2):first-child),
table:has(th:nth-last-child(3):first-child),
table:has(th:nth-last-child(4):first-child),
table:has(th:nth-last-child(5):first-child),
table:has(th:nth-last-child(6):first-child) {
    table-layout: fixed !important;
    width: 100% !important;
}

table th:nth-last-child(2):first-child, table td:nth-last-child(2):first-child { width: 15% !important; min-width: 0 !important; } 
table th:nth-last-child(1), table td:nth-last-child(1) { width: 85% !important; min-width: 0 !important; }

table th:nth-child(1):nth-last-child(3), table td:nth-child(1):nth-last-child(3) { width: 20% !important; min-width: 0 !important; } 
table th:nth-child(2):nth-last-child(2), table td:nth-child(2):nth-last-child(2) { width: 30% !important; min-width: 0 !important; } 
table th:nth-child(3):nth-last-child(1), table td:nth-child(3):nth-last-child(1) { width: 50% !important; min-width: 0 !important; }

table th:nth-child(1):nth-last-child(4), table td:nth-child(1):nth-last-child(4) { width: 10% !important; min-width: 0 !important; } 
table th:nth-child(2):nth-last-child(3), table td:nth-child(2):nth-last-child(3) { width: 40% !important; min-width: 0 !important; } 
table th:nth-child(3):nth-last-child(2), table td:nth-child(3):nth-last-child(2) { width: 10% !important; min-width: 0 !important; } 
table th:nth-child(4):nth-last-child(1), table td:nth-child(4):nth-last-child(1) { width: 40% !important; min-width: 0 !important; }

table th:nth-child(1):nth-last-child(5), table td:nth-child(1):nth-last-child(5) { width: 15% !important; min-width: 0 !important; } 
table th:nth-child(2):nth-last-child(4), table td:nth-child(2):nth-last-child(4) { width: 15% !important; min-width: 0 !important; } 
table th:nth-child(3):nth-last-child(3), table td:nth-child(3):nth-last-child(3) { width: 15% !important; min-width: 0 !important; } 
table th:nth-child(4):nth-last-child(2), table td:nth-child(4):nth-last-child(2) { width: 15% !important; min-width: 0 !important; } 
table th:nth-child(5):nth-last-child(1), table td:nth-child(5):nth-last-child(1) { width: 40% !important; min-width: 0 !important; }

table th:nth-child(1):nth-last-child(6), table td:nth-child(1):nth-last-child(6) { width: 8% !important; min-width: 0 !important; } 
table th:nth-child(2):nth-last-child(5), table td:nth-child(2):nth-last-child(5) { width: 15% !important; min-width: 0 !important; } 
table th:nth-child(3):nth-last-child(4), table td:nth-child(3):nth-last-child(4) { width: 27% !important; min-width: 0 !important; } 
table th:nth-child(4):nth-last-child(3), table td:nth-child(4):nth-last-child(3) { width: 8% !important; min-width: 0 !important; } 
table th:nth-child(5):nth-last-child(2), table td:nth-child(5):nth-last-child(2) { width: 15% !important; min-width: 0 !important; } 
table th:nth-child(6):nth-last-child(1), table td:nth-child(6):nth-last-child(1) { width: 27% !important; min-width: 0 !important; }

thead th { 
    font-size: 18px !important;
    position: sticky;
    top: 0; 
    background: white; 
    z-index: 10;
} 
.dataframe { 
    max-height: none !important; 
    overflow-y: visible !important; 
    overflow-x: auto !important; 
    display: block;
} 
.dataframe > div { 
    max-height: none !important; 
    overflow: visible !important; 
} 
td { 
    font-size: 18px !important;
    white-space: pre-wrap !important;
    word-break: keep-all !important; 
    line-height: 1.6; 
    padding: 10px; 
    vertical-align: top !important;
    text-align: left !important;
} 
td img {
    display: block;
    max-width: none !important;
}

#search_row {
    align-items: center !important; 
    margin-bottom: 5px !important;
}

#diff_cb_item, #mapped_cb_item {
    margin-top: 0 !important;
    padding-left: 15px !important; 
    width: max-content !important;
    min-width: max-content !important;
    flex-grow: 0 !important;
}
"""

if __name__ == "__main__":
    demo.launch(
        theme=gr.themes.Soft(),
        share=True,
        css=css
    )