"""Chart rendering for NOAA tide and conditions data.

Optional dependency — requires noaa-tides[viz] to be installed.
"""

# Marine color palette — shared across all chart renderers
OCEAN_BLUE = "#1B4F72"
TEAL = "#148F77"
SLATE = "#5D6D7E"
SAND = "#D4A017"
CORAL = "#E74C3C"
BG_COLOR = "#FAFAFA"
GRID_COLOR = "#E0E0E0"


def check_deps(format: str) -> None:
    """Raise ValueError with install hint if visualization deps are missing."""
    if format == "png":
        try:
            import matplotlib  # noqa: F401
        except ImportError:
            raise ValueError(
                "PNG charts require matplotlib. Install with: "
                "uv pip install noaa-tides[viz]"
            )
    elif format == "html":
        try:
            import plotly  # noqa: F401
        except ImportError:
            raise ValueError(
                "HTML charts require plotly. Install with: "
                "uv pip install noaa-tides[viz]"
            )