#!/usr/bin/env python3
import sqlite3
import json
import subprocess
import sys
from pathlib import Path

def read_bounds(tif):
    info = json.loads(subprocess.check_output(["gdalinfo", "-json", tif]))
    if "wgs84Extent" in info:
        coords = info["wgs84Extent"]["coordinates"][0]
        minlon, minlat = coords[0]
        maxlon, maxlat = coords[2]
    else:
        cc = info["cornerCoordinates"]
        minlon, minlat = cc["lowerLeft"]
        maxlon, maxlat = cc["upperRight"]

    if minlat > maxlat:
        minlat, maxlat = maxlat, minlat
    if minlon > maxlon:
        minlon, maxlon = maxlon, minlon

    return (
        round(minlon, 6),
        round(minlat, 6),
        round(maxlon, 6),
        round(maxlat, 6),
    )

def main():
    if len(sys.argv) != 4:
        print("Uso: python3 set_mbtiles_metadata_multi.py raster1.tif raster2.tif merged.mbtiles")
        sys.exit(1)

    tif1 = Path(sys.argv[1])
    tif2 = Path(sys.argv[2])
    mbtiles = Path(sys.argv[3])

    b1 = read_bounds(tif1)
    b2 = read_bounds(tif2)

    W = min(b1[0], b2[0])
    S = min(b1[1], b2[1])
    E = max(b1[2], b2[2])
    N = max(b1[3], b2[3])

    bounds = f"{W:.6f},{S:.6f},{E:.6f},{N:.6f}"

    conn = sqlite3.connect(mbtiles)
    cur = conn.cursor()

    cur.execute("CREATE TABLE IF NOT EXISTS metadata (name TEXT PRIMARY KEY, value TEXT);")

    cur.execute("SELECT MIN(zoom_level), MAX(zoom_level) FROM tiles;")
    minzoom, maxzoom = cur.fetchone()

    centerLon = (W + E) / 2
    centerLat = (S + N) / 2
    centerZoom = (minzoom + maxzoom) // 2
    center = f"{centerLon:.6f},{centerLat:.6f},{centerZoom}"

    cur.execute("REPLACE INTO metadata VALUES ('bounds', ?)", (bounds,))
    cur.execute("REPLACE INTO metadata VALUES ('center', ?)", (center,))
    cur.execute("REPLACE INTO metadata VALUES ('minzoom', ?)", (str(minzoom),))
    cur.execute("REPLACE INTO metadata VALUES ('maxzoom', ?)", (str(maxzoom),))
    cur.execute("REPLACE INTO metadata VALUES ('format', 'png')")
    cur.execute("REPLACE INTO metadata VALUES ('type', 'overlay')")
    cur.execute("REPLACE INTO metadata VALUES ('scheme', 'xyz')")

    conn.commit()
    conn.close()

    print("Metadata scritti correttamente:")
    print("bounds:", bounds)
    print("center:", center)
    print("minzoom:", minzoom)
    print("maxzoom:", maxzoom)
    print("format: png")
    print("type: overlay")
    print("scheme: xyz")

if __name__ == "__main__":
    main()