import sys
import pandas as pd
import numpy as np
import torch
import torch.nn as nn
import torch.optim as optim
from sklearn.model_selection import KFold
from sklearn.preprocessing import RobustScaler
from scipy.stats import pearsonr
import warnings
warnings.filterwarnings('ignore')

# ===== Feature Engineering =====
def feature_engineering(df):
    # 保持接口一致，实际特征工程已在feature.py完成
    return df

# ===== Configuration =====
class Config:
    TRAIN_PATH = "/AI4M/users/mjzhang/workspace/DRW/ZMJ/max_IC_mixed/train_aggregated.parquet"
    TEST_PATH = "/AI4M/users/mjzhang/workspace/DRW/ZMJ/max_IC_mixed/test_aggregated.parquet"
    SUBMISSION_PATH = "/AI4M/users/mjzhang/workspace/DRW/ZMJ/max_IC_mixed/sample_submission.csv"
    LABEL_COLUMN = "label"
    N_FOLDS = 3
    RANDOM_STATE = 42
    DEVICE = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
    BATCH_SIZE = 128
    EPOCHS = 20
    LEARNING_RATE = 1e-3

# ===== MLP Model Definition =====
class MLP(nn.Module):
    def __init__(self, input_dim):
        super().__init__()
        self.net = nn.Sequential(
            nn.Linear(input_dim, 256),
            nn.ReLU(),
            nn.Linear(256, 128),
            nn.ReLU(),
            # nn.Linear(1024, 512),
            # nn.ReLU(),
            # nn.Linear(512, 256),
            # nn.ReLU(),
            # nn.Linear(256, 128),
            # nn.ReLU(),
            # nn.Linear(256, 128),
            # nn.ReLU(),
            nn.Linear(128, 1)
        )
    def forward(self, x):
        return self.net(x)

# ===== Data Loading =====
def load_data():
    train_df = pd.read_parquet(Config.TRAIN_PATH)
    test_df = pd.read_parquet(Config.TEST_PATH)
    submission_df = pd.read_csv(Config.SUBMISSION_PATH)
    Config.FEATURES = [col for col in train_df.columns.tolist() if col != Config.LABEL_COLUMN]
    print(f"Loaded data - Train: {train_df.shape}, Test: {test_df.shape}, Submission: {submission_df.shape}")
    print(f"Total features: {len(Config.FEATURES)}")
    return train_df.reset_index(drop=True), test_df.reset_index(drop=True), submission_df

# ===== Model Training =====
def train_mlp(X_train, y_train, X_valid, y_valid, X_test, scaler):
    X_train = scaler.transform(X_train)
    X_valid = scaler.transform(X_valid)
    X_test = scaler.transform(X_test)
    X_train = torch.tensor(X_train, dtype=torch.float32, device=Config.DEVICE)
    y_train = torch.tensor(y_train.values, dtype=torch.float32, device=Config.DEVICE).view(-1, 1)
    X_valid = torch.tensor(X_valid, dtype=torch.float32, device=Config.DEVICE)
    y_valid = torch.tensor(y_valid.values, dtype=torch.float32, device=Config.DEVICE).view(-1, 1)
    X_test = torch.tensor(X_test, dtype=torch.float32, device=Config.DEVICE)
    model = MLP(X_train.shape[1]).to(Config.DEVICE)
    optimizer = optim.AdamW(model.parameters(), lr=Config.LEARNING_RATE, weight_decay=1e-4)  # L2正则
    criterion = nn.MSELoss()
    scheduler = optim.lr_scheduler.CosineAnnealingLR(optimizer, T_max=Config.EPOCHS)
    best_model = None
    best_score = -np.inf
    patience = 7  # 早停容忍轮数
    patience_counter = 0
    for epoch in range(Config.EPOCHS):
        model.train()
        idx = np.random.permutation(len(X_train))
        for i in range(0, len(X_train), Config.BATCH_SIZE):
            batch_idx = idx[i:i+Config.BATCH_SIZE]
            xb = X_train[batch_idx]
            yb = y_train[batch_idx]
            optimizer.zero_grad()
            pred = model(xb)
            loss = criterion(pred, yb)
            loss.backward()
            optimizer.step()
        scheduler.step()
        # 验证
        model.eval()
        with torch.no_grad():
            val_pred = model(X_valid).cpu().numpy().flatten()
            val_score = np.corrcoef(val_pred, y_valid.cpu().numpy().flatten())[0, 1]
            if val_score > best_score:
                best_score = val_score
                best_model = MLP(X_train.shape[1]).to(Config.DEVICE)
                best_model.load_state_dict(model.state_dict())
                patience_counter = 0
            else:
                patience_counter += 1
        if patience_counter >= patience:
            print(f"Early stopping at epoch {epoch+1}, best valid corr: {best_score:.4f}")
            break
    # 用最佳模型预测
    best_model.eval()
    with torch.no_grad():
        valid_pred = best_model(X_valid).cpu().numpy().flatten()
        test_pred = best_model(X_test).cpu().numpy().flatten()
    return valid_pred, test_pred

def train_and_evaluate(train_df, test_df):
    X_train = train_df[Config.FEATURES]
    y_train = train_df[Config.LABEL_COLUMN]
    X_test = test_df[Config.FEATURES]
    scaler = RobustScaler().fit(X_train)
    # 这里直接用全集训练
    valid_pred, test_pred = train_mlp(X_train, y_train, X_train, y_train, X_test, scaler)
    oof_preds = valid_pred  # 全集预测
    test_preds = test_pred
    score = pearsonr(y_train, valid_pred)[0]
    print(f"Train PearsonR (no CV): {score:.4f}")
    return oof_preds, test_preds

# ===== Submission =====
def create_submission(train_df, oof_preds, test_preds, submission_df):
    score = pearsonr(train_df[Config.LABEL_COLUMN], oof_preds)[0]
    print(f"\nMLP OOF PearsonR: {score:.4f}")
    submission = submission_df.copy()
    submission["prediction"] = test_preds
    submission.to_csv("/AI4M/users/mjzhang/workspace/DRW/ZMJ/max_IC_mixed/submission_mlp_new.csv", index=False)
    print("Saved: submission_mlp.csv")
    return score

# ===== Main Execution =====
if __name__ == "__main__":
    print("Loading data...")
    train_df, test_df, submission_df = load_data()
    print("\nTraining MLP model...")
    oof_preds, test_preds = train_and_evaluate(train_df, test_df)
    print("\nCreating submission...")
    score = create_submission(train_df, oof_preds, test_preds, submission_df)
    print(f"\nAll done! MLP OOF PearsonR: {score:.4f}")