import os

from pr.core.exceptions import ValidationError


def validate_file_path(path: str, must_exist: bool = False) -> str:
    if not path:
        raise ValidationError("File path cannot be empty")

    if must_exist and not os.path.exists(path):
        raise ValidationError(f"File does not exist: {path}")

    if must_exist and os.path.isdir(path):
        raise ValidationError(f"Path is a directory, not a file: {path}")

    return os.path.abspath(path)


def validate_directory_path(path: str, must_exist: bool = False, create: bool = False) -> str:
    if not path:
        raise ValidationError("Directory path cannot be empty")

    abs_path = os.path.abspath(path)

    if must_exist and not os.path.exists(abs_path):
        if create:
            os.makedirs(abs_path, exist_ok=True)
        else:
            raise ValidationError(f"Directory does not exist: {abs_path}")

    if os.path.exists(abs_path) and not os.path.isdir(abs_path):
        raise ValidationError(f"Path is not a directory: {abs_path}")

    return abs_path


def validate_model_name(model: str) -> str:
    if not model:
        raise ValidationError("Model name cannot be empty")

    if len(model) < 2:
        raise ValidationError("Model name too short")

    return model


def validate_api_url(url: str) -> str:
    if not url:
        raise ValidationError("API URL cannot be empty")

    if not url.startswith(("http://", "https://")):
        raise ValidationError("API URL must start with http:// or https://")

    return url


def validate_session_name(name: str) -> str:
    if not name:
        raise ValidationError("Session name cannot be empty")

    invalid_chars = ["/", "\\", ":", "*", "?", '"', "<", ">", "|"]
    for char in invalid_chars:
        if char in name:
            raise ValidationError(f"Session name contains invalid character: {char}")

    if len(name) > 255:
        raise ValidationError("Session name too long (max 255 characters)")

    return name


def validate_temperature(temp: float) -> float:
    if not 0.0 <= temp <= 2.0:
        raise ValidationError("Temperature must be between 0.0 and 2.0")

    return temp


def validate_max_tokens(tokens: int) -> int:
    if tokens < 1:
        raise ValidationError("Max tokens must be at least 1")

    if tokens > 100000:
        raise ValidationError("Max tokens too high (max 100000)")

    return tokens