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

EPS = 1e-6  # tolleranza per confronti float

def almost_equal(a, b):
    return abs(a - b) < EPS

def read_gdal_bounds(raster):
    """Legge i bounds W,S,E,N dal TIFF usando gdalinfo -json, arrotondati a 6 decimali."""
    info = subprocess.check_output(["gdalinfo", "-json", raster])
    info = json.loads(info)

    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"]

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

    # Arrotondamento a 6 decimali (standard MBTiles)
    return (
        round(minlon, 6),
        round(minlat, 6),
        round(maxlon, 6),
        round(maxlat, 6),
    )

def read_mbtiles_bounds(cur):
    cur.execute("SELECT value FROM metadata WHERE name='bounds';")
    row = cur.fetchone()
    if not row:
        return None
    try:
        w, s, e, n = map(float, row[0].split(","))
        return (w, s, e, n)
    except:
        return None

def write_bounds(cur, bounds):
    w, s, e, n = bounds
    value = f"{w:.6f},{s:.6f},{e:.6f},{n:.6f}"
    cur.execute("REPLACE INTO metadata (name,value) VALUES ('bounds', ?)", (value,))
    return value

def main():
    if len(sys.argv) != 3:
        print("Uso: python3 verify_bounds_tileservergl.py <raster.tif> <file.mbtiles>")
        sys.exit(1)

    raster = Path(sys.argv[1])
    mbtiles = Path(sys.argv[2])

    if not raster.exists():
        print(f"Raster non trovato: {raster}")
        sys.exit(1)
    if not mbtiles.exists():
        print(f"MBTiles non trovato: {mbtiles}")
        sys.exit(1)

    print("== Verifica bounds per TileServer GL (W,S,E,N) ==")

    # Bounds dal TIFF
    tiff_bounds = read_gdal_bounds(raster)
    print(f"Bounds TIFF (W,S,E,N): {tiff_bounds}")

    # Apri MBTiles
    conn = sqlite3.connect(mbtiles)
    cur = conn.cursor()

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

    # Bounds MBTiles
    mb_bounds = read_mbtiles_bounds(cur)
    print(f"Bounds MBTiles: {mb_bounds}")

    # Se mancano → scrivili
    if mb_bounds is None:
        print("✘ Bounds mancanti → FIX")
        new_value = write_bounds(cur, tiff_bounds)
        print(f"✔ Bounds scritti: {new_value}")
        conn.commit()
        conn.close()
        print("\n== Verifica completata ==")
        return

    # Confronto con tolleranza
    w1, s1, e1, n1 = tiff_bounds
    w2, s2, e2, n2 = mb_bounds

    if not (almost_equal(w1, w2) and almost_equal(s1, s2) and almost_equal(e1, e2) and almost_equal(n1, n2)):
        print("✘ Bounds NON corretti → FIX")
        new_value = write_bounds(cur, tiff_bounds)
        print(f"✔ Bounds aggiornati a: {new_value}")
        conn.commit()
    else:
        print("✔ Bounds OK (nessuna correzione necessaria)")

    conn.close()
    print("\n== Verifica completata ==")

if __name__ == "__main__":
    main()