"""
Pipeline configuration module.

Pydantic models for validating and loading the pipeline.yaml configuration.
"""

from typing import List, Dict, Any, Optional, Literal
from pathlib import Path

import yaml
from pydantic import BaseModel, Field, field_validator


class TALibIndicator(BaseModel):
    """Configuration for a single TA-Lib indicator."""
    name: str
    params: Dict[str, Any] = Field(default_factory=dict)


class FeatureEngineeringConfig(BaseModel):
    """Feature engineering stage configuration."""
    enabled: bool = True
    talib_indicators: List[TALibIndicator] = Field(default_factory=list)
    candle_features: bool = True
    custom_features: List[str] = Field(default_factory=list)


class ProgrammaticLabelsConfig(BaseModel):
    """Configuration for programmatic TA-Lib pattern labels."""
    enabled: bool = True
    talib_patterns: List[str] = Field(default_factory=list)


class AnnotationIngestionConfig(BaseModel):
    """Annotation ingestion stage configuration."""
    enabled: bool = True
    label_encoding: Literal["window", "bio"] = "window"
    window_size: int = 30
    context_padding: int = 20
    min_confidence: int = 1
    programmatic_labels: ProgrammaticLabelsConfig = Field(
        default_factory=ProgrammaticLabelsConfig
    )
    merge_strategy: Literal["human_priority", "programmatic_priority", "both"] = "human_priority"


class MLflowConfig(BaseModel):
    """MLflow experiment tracking configuration."""
    tracking_uri: str = "http://mlflow:5000"
    experiment_name: str = "candlestick_patterns"
    log_artifacts: bool = True
    register_model: bool = False


class TrainingConfig(BaseModel):
    """Training stage configuration."""
    enabled: bool = True
    model_type: Literal["random_forest", "xgboost"] = "random_forest"
    split_method: Literal["temporal", "random"] = "temporal"
    test_split: float = Field(0.2, ge=0.0, le=1.0)
    validation_split: float = Field(0.1, ge=0.0, le=1.0)
    class_weights: Optional[Literal["balanced"]] = "balanced"
    hyperparameters: Dict[str, Any] = Field(default_factory=dict)
    mlflow: MLflowConfig = Field(default_factory=MLflowConfig)
    
    @field_validator("test_split", "validation_split")
    @classmethod
    def validate_split(cls, v):
        if not 0.0 <= v <= 1.0:
            raise ValueError("Split must be between 0.0 and 1.0")
        return v


class InferenceConfig(BaseModel):
    """Inference stage configuration."""
    enabled: bool = True
    model_source: Literal["mlflow", "local"] = "local"
    mlflow_model_name: Optional[str] = "candlestick_pattern_v1"
    mlflow_model_stage: Literal["Production", "Staging", "None"] = "Production"
    local_model_path: str = "models/best_model.pkl"
    batch_size: int = 1000
    use_training_config: bool = True


class DataConfig(BaseModel):
    """Data paths configuration."""
    raw_path: str = "data/raw/OHLCV.csv"
    enriched_path: str = "data/enriched/features.csv"
    labeled_path: str = "data/labeled/dataset.csv"
    annotations_path: str = "data/annotations/export.json"


class StagesConfig(BaseModel):
    """All pipeline stages configuration."""
    feature_engineering: FeatureEngineeringConfig = Field(
        default_factory=FeatureEngineeringConfig
    )
    annotation_ingestion: AnnotationIngestionConfig = Field(
        default_factory=AnnotationIngestionConfig
    )
    training: TrainingConfig = Field(default_factory=TrainingConfig)
    inference: InferenceConfig = Field(default_factory=InferenceConfig)


class PipelineConfig(BaseModel):
    """Root pipeline configuration."""
    data: DataConfig = Field(default_factory=DataConfig)
    stages: StagesConfig = Field(default_factory=StagesConfig)


def load_config(config_path: str | Path) -> PipelineConfig:
    """
    Load and validate pipeline configuration from YAML file.
    
    Args:
        config_path: Path to pipeline.yaml file
        
    Returns:
        Validated PipelineConfig object
        
    Raises:
        FileNotFoundError: If config file doesn't exist
        ValueError: If config validation fails
        yaml.YAMLError: If YAML parsing fails
    """
    config_path = Path(config_path)
    
    if not config_path.exists():
        raise FileNotFoundError(f"Config file not found: {config_path}")
    
    with open(config_path, 'r') as f:
        config_dict = yaml.safe_load(f)
    
    try:
        return PipelineConfig(**config_dict)
    except Exception as e:
        raise ValueError(f"Config validation failed: {e}")


def get_default_config() -> PipelineConfig:
    """
    Get default pipeline configuration.
    
    Returns:
        PipelineConfig with default values
    """
    return PipelineConfig()