import os
import tempfile
import json
from io import BytesIO
import geopandas as gpd
from py7zr import SevenZipFile
import pyogrio


def find_data_source(extract_dir: str):
    """
    Cari data sumber (.gdb atau .shp) di dalam folder hasil ekstrak.
    """
    for root, dirs, _ in os.walk(extract_dir):
        for d in dirs:
            if d.lower().endswith(".gdb"):
                return os.path.join(root, d)

    for root, _, files in os.walk(extract_dir):
        for f in files:
            if f.lower().endswith(".shp"):
                return os.path.join(root, f)

    raise ValueError("Tidak ditemukan data source yang didukung (.gdb atau .shp).")


def get_main_layer(gdb_path: str):
    """
    Ambil nama layer utama dari geodatabase (.gdb).
    """
    try:
        layers = pyogrio.list_layers(gdb_path)
        for layer in layers:
            if not layer[0].lower().endswith("__attach"):
                return layer[0]
        if layers:
            return layers[0][0]
        raise ValueError(f"Tidak ada layer utama yang valid di {gdb_path}")
    except Exception as e:
        raise ValueError(f"Gagal membaca daftar layer GDB: {e}")


def read_mpk(path: str):
    mpk_bytes = None
    with open(path, "rb") as f:
        mpk_bytes = f.read()
        
    if not mpk_bytes:
        raise ValueError("File MPK kosong atau tidak valid.")

    with tempfile.TemporaryDirectory() as tempdir:
        try:
            with SevenZipFile(BytesIO(mpk_bytes), mode="r") as z:
                z.extractall(path=tempdir)
        except Exception as e:
            raise ValueError(f"File MPK rusak atau tidak valid: {e}")

        src_path = find_data_source(tempdir)

        if src_path.lower().endswith(".gdb"):
            layer_name = get_main_layer(src_path)
            gdf = gpd.read_file(src_path, layer=layer_name)
        else:
            gdf = gpd.read_file(src_path)

        if gdf.crs is None:
            raise ValueError("CRS tidak terdeteksi. Pastikan file memiliki informasi proyeksi (.prj).")

        gdf = gdf.to_crs(epsg=4326)

        print(f"[INFO] Berhasil membaca {len(gdf)} fitur")
        return gdf