"""Titiler-based Mars tile server for MGS MOLA ClrShade global basemap"""

import math

from fastapi import FastAPI
from pyproj import CRS
from morecantile import tms, TileMatrixSet
from rio_tiler.io import Reader

from titiler.core.factory import TilerFactory

# Mars SimpleCylindrical CRS (equidistant cylindrical projection in meters)
MARS_CRS = CRS.from_proj4(
    "+proj=eqc +lat_ts=0 +lat_0=0 +lon_0=0 +x_0=0 +y_0=0 "
    "+a=3396190 +b=3396190 +units=m +no_defs"
)

# Mars extent in equidistant cylindrical projection
# x = R × lon_rad, y = R × lat_rad
_R = 3396190
_MAX_X = _R * math.pi        # ≈ 10,669,442 m (corresponds to ±180°)
_MAX_Y = _R * math.pi / 2    # ≈  5,334,721 m (corresponds to ±90°)

# Custom TMS for Mars with matrix_scale=[2, 1] to match Cesium GeographicTilingScheme
MARS_TMS = TileMatrixSet.custom(
    crs=MARS_CRS,
    extent=(-_MAX_X, -_MAX_Y, _MAX_X, _MAX_Y),
    identifier="MarsCylindrical",
    matrix_scale=[2, 1],
)

# Register custom TMS
tms = tms.register({"MarsCylindrical": MARS_TMS})

# Create FastAPI app
app = FastAPI(
    title="Titiler Mars",
    description="Mars MGS MOLA Color-Shaded Relief global tile server powered by Titiler",
)

# Create COG Tiler with Mars TMS support
cog = TilerFactory(
    reader=Reader,
    supported_tms=tms,
)

app.include_router(cog.router, tags=["Cloud Optimized GeoTIFF"])


@app.get("/", include_in_schema=False)
def landing():
    """Landing page."""
    return {
        "title": "Titiler Mars Tile Server",
        "description": "Mars MGS MOLA Color-Shaded Relief global tile server",
        "endpoints": {
            "tiles": "/tiles/MarsCylindrical/{z}/{x}/{y}?url=<data_url>",
            "tilejson": "/MarsCylindrical/tilejson.json?url=<data_url>",
            "info": "/info?url=<data_url>",
            "preview": "/preview.png?url=<data_url>&max_size=512",
            "docs": "/docs",
        },
    }