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

def read_gdal_bounds(raster):
    """Legge i bounds WGS84 dal TIFF usando gdalinfo -json."""
    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 latitudine
    if minlat > maxlat:
        minlat, maxlat = maxlat, minlat

    return (minlon, minlat, maxlon, maxlat)


def read_mbtiles_metadata(mbtiles):
    """Legge metadata e tile info da un MBTiles."""
    conn = sqlite3.connect(mbtiles)
    cur = conn.cursor()

    # Verifica tabella tiles
    cur.execute("SELECT COUNT(*) FROM sqlite_master WHERE type='table' AND name='tiles';")
    if cur.fetchone()[0] == 0:
        raise RuntimeError("La tabella 'tiles' non esiste nell'MBTiles.")

    # Conta tile
    cur.execute("SELECT COUNT(*) FROM tiles;")
    tile_count = cur.fetchone()[0]
    if tile_count == 0:
        raise RuntimeError("La tabella 'tiles' è vuota.")

    # Zoom min/max
    cur.execute("SELECT MIN(zoom_level), MAX(zoom_level) FROM tiles;")
    minzoom, maxzoom = cur.fetchone()

    # Metadata
    cur.execute("SELECT name, value FROM metadata;")
    metadata = dict(cur.fetchall())

    conn.close()
    return tile_count, minzoom, maxzoom, metadata


def main():
    if len(sys.argv) != 3:
        print("Uso: python3 verify_mbtiles_metadata.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 metadata MBTiles ==")

    # 1) Bounds dal TIFF
    minlon, minlat, maxlon, maxlat = read_gdal_bounds(raster)
    print(f"Bounds TIFF: {minlon},{minlat},{maxlon},{maxlat}")

    # 2) Lettura MBTiles
    tile_count, minzoom, maxzoom, metadata = read_mbtiles_metadata(mbtiles)

    print(f"Tile count: {tile_count}")
    print(f"Zoom effettivi: {minzoom}..{maxzoom}")

    # 3) Confronto bounds
    mb_bounds = metadata.get("bounds", None)
    if mb_bounds:
        mb_minlon, mb_minlat, mb_maxlon, mb_maxlat = map(float, mb_bounds.split(","))
        print(f"Bounds MBTiles: {mb_bounds}")

        if abs(mb_minlon - minlon) < 1e-4 and \
           abs(mb_minlat - minlat) < 1e-4 and \
           abs(mb_maxlon - maxlon) < 1e-4 and \
           abs(mb_maxlat - maxlat) < 1e-4:
            print("✔ Bounds OK")
        else:
            print("✘ Bounds NON corrispondono al TIFF")
    else:
        print("✘ Metadata 'bounds' mancante")

    # 4) Confronto minzoom/maxzoom
    if "minzoom" in metadata and "maxzoom" in metadata:
        mz = int(metadata["minzoom"])
        xz = int(metadata["maxzoom"])
        if mz == minzoom and xz == maxzoom:
            print("✔ minzoom/maxzoom OK")
        else:
            print(f"✘ minzoom/maxzoom NON coerenti: metadata={mz}..{xz}, reali={minzoom}..{maxzoom}")
    else:
        print("✘ Metadata minzoom/maxzoom mancanti")

    # 5) Center
    if "center" in metadata:
        print(f"Center: {metadata['center']}")
    else:
        print("✘ Metadata 'center' mancante")

    print("\n== Verifica completata ==")


if __name__ == "__main__":
    main()