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

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

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

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

def main():
    if len(sys.argv) != 3:
        print("Uso: python3 set_mbtiles_metadata_multi.py <dir_tif> <merged.mbtiles>")
        sys.exit(1)

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

    if not tif_dir.exists() or not tif_dir.is_dir():
        print(f"Directory TIFF non valida: {tif_dir}")
        sys.exit(1)

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

    # Trova tutti i TIFF nella directory
    tifs = sorted([p for p in tif_dir.iterdir() if p.suffix.lower() in (".tif", ".tiff")])

    if not tifs:
        print("Nessun TIFF trovato nella directory.")
        sys.exit(1)

    print(f"Trovati {len(tifs)} TIFF:")
    for t in tifs:
        print(" -", t.name)

    # Calcolo bounds unificati
    bounds_list = [read_bounds(t) for t in tifs]

    W = min(b[0] for b in bounds_list)
    S = min(b[1] for b in bounds_list)
    E = max(b[2] for b in bounds_list)
    N = max(b[3] for b in bounds_list)

    bounds = f"{W:.6f},{S:.6f},{E:.6f},{N:.6f}"
    print("\nBounds unificati:", bounds)

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

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

    # Zoom reali dal MBTiles
    cur.execute("SELECT MIN(zoom_level), MAX(zoom_level) FROM tiles;")
    minzoom, maxzoom = cur.fetchone()

    print(f"Zoom reali: {minzoom}..{maxzoom}")

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

    # Scrittura metadata
    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("\nMetadata 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()