"""
Medical Drug Interaction Training Pipeline

This pipeline trains a model to detect drug-drug interactions (DDI)
from clinical documents in CCDA/FHIR formats.
"""
from kfp import dsl
from kfp import compiler


@dsl.component(
    base_image="python:3.11-slim",
    packages_to_install=["pandas", "lxml", "fhir.resources"]
)
def preprocess_ccda(
    input_path: str,
    output_path: dsl.OutputPath("Dataset")
):
    """Parse CCDA XML files and extract medication data."""
    import json
    from lxml import etree
    
    # CCDA namespace
    NS = {"hl7": "urn:hl7-org:v3"}
    
    medications = []
    
    # Parse CCDA and extract medications
    # (simplified example - full implementation in production)
    result = {
        "source": "ccda",
        "medications": medications,
        "processed": True
    }
    
    with open(output_path, 'w') as f:
        json.dump(result, f)


@dsl.component(
    base_image="python:3.11-slim",
    packages_to_install=["pandas", "fhir.resources"]
)
def preprocess_fhir(
    input_path: str,
    output_path: dsl.OutputPath("Dataset")
):
    """Parse FHIR R4 resources and extract medication data."""
    import json
    
    medications = []
    
    result = {
        "source": "fhir",
        "medications": medications,
        "processed": True
    }
    
    with open(output_path, 'w') as f:
        json.dump(result, f)


@dsl.component(
    base_image="python:3.11-slim",
    packages_to_install=["requests"]
)
def normalize_rxnorm(
    input_dataset: dsl.Input["Dataset"],
    output_path: dsl.OutputPath("Dataset")
):
    """Normalize medication names using RxNorm API."""
    import json
    
    with open(input_dataset.path, 'r') as f:
        data = json.load(f)
    
    # Normalize medications via RxNorm
    # (API call implementation)
    
    data["normalized"] = True
    
    with open(output_path, 'w') as f:
        json.dump(data, f)


@dsl.component(
    base_image="huggingface/transformers-pytorch-gpu:latest",
    packages_to_install=["datasets", "accelerate", "scikit-learn"]
)
def train_ddi_model(
    train_dataset: dsl.Input["Dataset"],
    model_name: str,
    epochs: int,
    learning_rate: float,
    output_model: dsl.OutputPath("Model")
):
    """Fine-tune a transformer model for DDI detection."""
    import json
    import os
    from transformers import (
        AutoTokenizer,
        AutoModelForSequenceClassification,
        TrainingArguments,
        Trainer
    )
    
    # Load base model
    tokenizer = AutoTokenizer.from_pretrained(model_name)
    model = AutoModelForSequenceClassification.from_pretrained(
        model_name,
        num_labels=5  # DDI severity levels
    )
    
    # Training configuration
    training_args = TrainingArguments(
        output_dir=output_model,
        num_train_epochs=epochs,
        learning_rate=learning_rate,
        per_device_train_batch_size=16,
        evaluation_strategy="epoch",
        save_strategy="epoch",
        load_best_model_at_end=True,
    )
    
    # Train (placeholder - needs actual dataset loading)
    print(f"Training {model_name} for {epochs} epochs")
    
    # Save model
    model.save_pretrained(output_model)
    tokenizer.save_pretrained(output_model)


@dsl.component(
    base_image="python:3.11-slim",
    packages_to_install=["scikit-learn", "pandas"]
)
def evaluate_model(
    model_path: dsl.Input["Model"],
    test_dataset: dsl.Input["Dataset"],
    metrics_output: dsl.OutputPath("Metrics")
):
    """Evaluate the trained model and output metrics."""
    import json
    
    metrics = {
        "f1_micro": 0.0,
        "f1_macro": 0.0,
        "precision": 0.0,
        "recall": 0.0,
        "auprc": 0.0
    }
    
    with open(metrics_output, 'w') as f:
        json.dump(metrics, f)


@dsl.pipeline(
    name="med-rx-ddi-training",
    description="Train DDI detection model on CCDA/FHIR clinical data"
)
def med_rx_training_pipeline(
    ccda_input_path: str = "s3://minio/data/ccda/",
    fhir_input_path: str = "s3://minio/data/fhir/",
    base_model: str = "emilyalsentzer/Bio_ClinicalBERT",
    epochs: int = 3,
    learning_rate: float = 2e-5
):
    """
    Full DDI training pipeline:
    1. Preprocess CCDA and FHIR data
    2. Normalize medications via RxNorm
    3. Train transformer model
    4. Evaluate and output metrics
    """
    # Preprocess data sources
    ccda_task = preprocess_ccda(input_path=ccda_input_path)
    fhir_task = preprocess_fhir(input_path=fhir_input_path)
    
    # Normalize CCDA data
    normalize_ccda = normalize_rxnorm(input_dataset=ccda_task.outputs["output_path"])
    
    # Train model (using CCDA for now)
    train_task = train_ddi_model(
        train_dataset=normalize_ccda.outputs["output_path"],
        model_name=base_model,
        epochs=epochs,
        learning_rate=learning_rate
    )
    
    # Evaluate
    eval_task = evaluate_model(
        model_path=train_task.outputs["output_model"],
        test_dataset=normalize_ccda.outputs["output_path"]
    )


if __name__ == "__main__":
    compiler.Compiler().compile(
        pipeline_func=med_rx_training_pipeline,
        package_path="med_rx_training_pipeline.yaml"
    )
    print("Pipeline compiled to med_rx_training_pipeline.yaml")
