#!/usr/bin/env python3
"""
Answer/Prediction Bias 분석 스크립트

1. GT Answer Distribution: 정답이 A, B, C, D 중 어디에 편중되어 있는지
2. Model Prediction Distribution: 모델이 특정 선택지를 더 많이 선택하는지

Usage:
    python experiments/analyze_answer_bias.py <model_result.xlsx> [--subset far_close]
    python experiments/analyze_answer_bias.py --compare <file1.xlsx> <file2.xlsx> ...
"""

import argparse
import sys
import pandas as pd
import numpy as np
from pathlib import Path
from typing import Dict, List
from collections import Counter


class TeeWriter:
    """stdout을 터미널과 파일에 동시에 출력"""
    def __init__(self, filepath):
        self.terminal = sys.stdout
        self.file = open(filepath, 'w', encoding='utf-8')

    def write(self, message):
        self.terminal.write(message)
        self.file.write(message)

    def flush(self):
        self.terminal.flush()
        self.file.flush()

    def close(self):
        self.file.close()
        return self.terminal


def extract_answer_letter(val) -> str:
    """예측값에서 A/B/C/D 추출 (예: 'D. basket' -> 'D')"""
    if pd.isna(val):
        return 'INVALID'
    val = str(val).strip()
    if len(val) == 0:
        return 'INVALID'
    first_char = val[0].upper()
    if first_char in ['A', 'B', 'C', 'D']:
        return first_char
    return 'INVALID'


def analyze_bias(df: pd.DataFrame, subset_name: str = "ALL") -> Dict:
    """
    Answer/Prediction bias 분석
    """
    # GT Answer 분포 (이미 A/B/C/D 형태)
    gt_dist = Counter(df['answer'])
    gt_total = sum(gt_dist.values())

    # Prediction 분포 - 첫 글자 추출
    pred_letters = df['prediction'].apply(extract_answer_letter)
    pred_dist = Counter(pred_letters)
    pred_total = sum(v for k, v in pred_dist.items() if k != 'INVALID')

    # 정답률 by GT position
    acc_by_pos = {}
    for ans in ['A', 'B', 'C', 'D']:
        subset = df[df['answer'] == ans]
        if len(subset) > 0:
            acc_by_pos[ans] = subset['hit'].mean() * 100
        else:
            acc_by_pos[ans] = 0

    # Prediction이 GT와 일치하는 비율 (hit rate by prediction position)
    # prediction에서 첫 글자 추출해서 매칭
    df_with_pred_letter = df.copy()
    df_with_pred_letter['pred_letter'] = pred_letters.values
    hit_by_pred = {}
    for pred in ['A', 'B', 'C', 'D']:
        subset = df_with_pred_letter[df_with_pred_letter['pred_letter'] == pred]
        if len(subset) > 0:
            hit_by_pred[pred] = subset['hit'].mean() * 100
        else:
            hit_by_pred[pred] = 0

    return {
        'subset': subset_name,
        'total': len(df),
        'gt_dist': {k: gt_dist.get(k, 0) for k in ['A', 'B', 'C', 'D']},
        'gt_pct': {k: gt_dist.get(k, 0) / gt_total * 100 if gt_total > 0 else 0 for k in ['A', 'B', 'C', 'D']},
        'pred_dist': {k: pred_dist.get(k, 0) for k in ['A', 'B', 'C', 'D']},
        'pred_pct': {k: pred_dist.get(k, 0) / pred_total * 100 if pred_total > 0 else 0 for k in ['A', 'B', 'C', 'D']},
        'acc_by_gt_pos': acc_by_pos,
        'hit_by_pred_pos': hit_by_pred,
        'overall_acc': df['hit'].mean() * 100
    }


def print_bias_report(xlsx_path: str, results: List[Dict]):
    """Bias 분석 리포트 출력"""
    model_name = Path(xlsx_path).stem.replace('_EmbSpatialBench_openai_result', '')
    # 이름 축약
    if len(model_name) > 50:
        model_name = model_name[:47] + "..."

    print(f"\n{'='*80}")
    print(f"Model: {model_name}")
    print(f"{'='*80}")

    for r in results:
        print(f"\n--- {r['subset']} (n={r['total']}) ---")

        # GT Distribution
        print(f"\n  GT Answer Distribution:")
        print(f"    {'Pos':<5} {'Count':<8} {'Pct':<8} {'Acc when GT':<12}")
        print(f"    {'-'*35}")
        for pos in ['A', 'B', 'C', 'D']:
            print(f"    {pos:<5} {r['gt_dist'][pos]:<8} {r['gt_pct'][pos]:.1f}%{'':<4} {r['acc_by_gt_pos'][pos]:.1f}%")

        # Prediction Distribution
        print(f"\n  Model Prediction Distribution:")
        print(f"    {'Pos':<5} {'Count':<8} {'Pct':<8} {'Acc when Pred':<12}")
        print(f"    {'-'*35}")
        for pos in ['A', 'B', 'C', 'D']:
            print(f"    {pos:<5} {r['pred_dist'][pos]:<8} {r['pred_pct'][pos]:.1f}%{'':<4} {r['hit_by_pred_pos'][pos]:.1f}%")

        # Bias 지표
        gt_std = np.std([r['gt_pct'][p] for p in ['A', 'B', 'C', 'D']])
        pred_std = np.std([r['pred_pct'][p] for p in ['A', 'B', 'C', 'D']])

        print(f"\n  Bias Indicators:")
        print(f"    GT Distribution Std: {gt_std:.2f}%p (uniform=0)")
        print(f"    Pred Distribution Std: {pred_std:.2f}%p (uniform=0)")
        print(f"    Overall Accuracy: {r['overall_acc']:.1f}%")


def analyze_model(xlsx_path: str, include_subsets: bool = True) -> List[Dict]:
    """모델 결과 분석"""
    df = pd.read_excel(xlsx_path)

    results = []

    # 전체 분석
    results.append(analyze_bias(df, "ALL"))

    if include_subsets:
        # FAR/CLOSE만 분석
        far_close_df = df[df['category'].isin(['far', 'close'])]
        if len(far_close_df) > 0:
            results.append(analyze_bias(far_close_df, "FAR+CLOSE"))

        # Category별 분석
        for cat in ['far', 'close']:
            cat_df = df[df['category'] == cat]
            if len(cat_df) > 0:
                results.append(analyze_bias(cat_df, cat.upper()))

    return results


def compare_models_bias(xlsx_paths: List[str]):
    """여러 모델의 bias 비교 (요약 테이블)"""

    print(f"\n{'='*100}")
    print("MODEL BIAS COMPARISON SUMMARY")
    print(f"{'='*100}")

    # Header
    print(f"\n{'Model':<45} {'Subset':<12} {'GT Std':<10} {'Pred Std':<10} {'Pred Max':<12} {'Acc':<8}")
    print("-" * 97)

    for xlsx_path in xlsx_paths:
        model_name = Path(xlsx_path).stem.replace('_EmbSpatialBench_openai_result', '')
        if len(model_name) > 43:
            model_name = model_name[:40] + "..."

        results = analyze_model(xlsx_path, include_subsets=True)

        for r in results:
            gt_std = np.std([r['gt_pct'][p] for p in ['A', 'B', 'C', 'D']])
            pred_std = np.std([r['pred_pct'][p] for p in ['A', 'B', 'C', 'D']])

            # 가장 많이 선택한 position
            max_pred_pos = max(r['pred_pct'], key=r['pred_pct'].get)
            max_pred_pct = r['pred_pct'][max_pred_pos]

            if r['subset'] == 'ALL':
                print(f"{model_name:<45} {r['subset']:<12} {gt_std:.1f}%p{'':<4} {pred_std:.1f}%p{'':<4} {max_pred_pos}({max_pred_pct:.1f}%){'':<2} {r['overall_acc']:.1f}%")
            else:
                print(f"{'':<45} {r['subset']:<12} {gt_std:.1f}%p{'':<4} {pred_std:.1f}%p{'':<4} {max_pred_pos}({max_pred_pct:.1f}%){'':<2} {r['overall_acc']:.1f}%")


EVAL_OUTPUT_DIR = 'VLMEvalKit/outputs'

DEFAULT_MODELS = [
    # Molmo-7B
    'molmo-7B-O-0924/molmo-7B-O-0924',
    'molmo-7B-O-0924-data_scale_exp_80k/molmo-7B-O-0924-data_scale_exp_80k',
    'molmo-7B-O-0924-data_scale_exp_400k/molmo-7B-O-0924-data_scale_exp_400k',
    'molmo-7B-O-0924-data_scale_exp_800k/molmo-7B-O-0924-data_scale_exp_800k',
    'molmo-7B-O-0924-data_scale_exp_2m/molmo-7B-O-0924-data_scale_exp_2m',
    # NVILA-Lite-2B
    'NVILA-Lite-2B/NVILA-Lite-2B',
    'NVILA-Lite-2B-data-scale-exp-80k/NVILA-Lite-2B-data-scale-exp-80k',
    'NVILA-Lite-2B-data-scale-exp-400k/NVILA-Lite-2B-data-scale-exp-400k',
    'NVILA-Lite-2B-data-scale-exp-800k/NVILA-Lite-2B-data-scale-exp-800k',
    'NVILA-Lite-2B-data-scale-exp-2m/NVILA-Lite-2B-data-scale-exp-2m',
    'RoboRefer-2B-SFT/RoboRefer-2B-SFT',
    # Qwen2.5-VL-3B
    'Qwen2.5-VL-3B-Instruct/Qwen2.5-VL-3B-Instruct',
    'Qwen2.5-VL-3B-Instruct-data_scale_exp_80k/Qwen2.5-VL-3B-Instruct-data_scale_exp_80k',
    'Qwen2.5-VL-3B-Instruct-data_scale_exp_400k/Qwen2.5-VL-3B-Instruct-data_scale_exp_400k',
    'Qwen2.5-VL-3B-Instruct-data_scale_exp_800k/Qwen2.5-VL-3B-Instruct-data_scale_exp_800k',
    'Qwen2.5-VL-3B-Instruct-data_scale_exp_2m/Qwen2.5-VL-3B-Instruct-data_scale_exp_2m',
]


def get_default_xlsx_paths():
    return [f'{EVAL_OUTPUT_DIR}/{m}_EmbSpatialBench_openai_result.xlsx' for m in DEFAULT_MODELS]


def main():
    parser = argparse.ArgumentParser(description='Answer/Prediction Bias 분석')
    parser.add_argument('xlsx_files', nargs='*', help='Model result xlsx files (없으면 기본 모델 사용)')
    parser.add_argument('--compare', action='store_true', help='Compare multiple models (summary only)')
    parser.add_argument('--detail', action='store_true', help='Show detailed report for each model')
    parser.add_argument('--output', '-o', type=str, help='Save results to file')

    args = parser.parse_args()

    xlsx_files = args.xlsx_files if args.xlsx_files else get_default_xlsx_paths()

    if args.output:
        tee = TeeWriter(args.output)
        sys.stdout = tee

    if args.compare and not args.detail:
        compare_models_bias(xlsx_files)
    else:
        for xlsx_path in xlsx_files:
            results = analyze_model(xlsx_path)
            print_bias_report(xlsx_path, results)

        if len(xlsx_files) > 1:
            compare_models_bias(xlsx_files)

    if args.output:
        sys.stdout = tee.close()
        print(f"Results saved to {args.output}")


if __name__ == '__main__':
    main()