# -*- coding: utf-8 -*-
# I2 Bab 3: reklasifikasi kemiringan dan luas kelas lereng per KPH. Penulis: Badar Mubarok Yogaswara
# Jalankan setelah i2_02_turunan_dem.py (memakai slope_persen.tif di folder hasil).
import os
import processing
from qgis.core import QgsRasterLayer, QgsVectorLayer

PAKET = os.environ.get("I2_DATA", r"C:/KPH_Contoh/paket-data")
HASIL = r"C:/temp/hasil_i2"

persen = QgsRasterLayer(os.path.join(HASIL, "slope_persen.tif"), "slope_persen")
batas = QgsVectorLayer(os.path.join(PAKET, "Batas_KPH.gpkg") + "|layername=Batas_KPH", "Batas_KPH", "ogr")

# tabel: awal, akhir, kelas baru. Aturan batas: awal < nilai <= akhir (RANGE_BOUNDARIES = 0)
tabel = [-1, 8, 1,
         8, 15, 2,
         15, 25, 3,
         25, 45, 4,
         45, 1000, 5]
kelas = processing.run("native:reclassifybytable", {
    "INPUT_RASTER": persen, "RASTER_BAND": 1, "TABLE": tabel, "NO_DATA": -9999,
    "RANGE_BOUNDARIES": 0, "NODATA_FOR_MISSING": False, "DATA_TYPE": 5,
    "OUTPUT": os.path.join(HASIL, "kelas_lereng.tif")})["OUTPUT"]

lyr_kelas = QgsRasterLayer(kelas, "kelas_lereng")
hist = processing.run("native:zonalhistogram", {
    "INPUT_RASTER": lyr_kelas, "RASTER_BAND": 1, "INPUT_VECTOR": batas, "COLUMN_PREFIX": "K",
    "OUTPUT": os.path.join(HASIL, "luas_kelas_per_kph.gpkg")})["OUTPUT"]

luas_piksel_ha = lyr_kelas.rasterUnitsPerPixelX() * lyr_kelas.rasterUnitsPerPixelY() / 10000.0
hasil = QgsVectorLayer(hist, "hist", "ogr")
print("Luas kelas lereng (ha) per KPH; piksel = %.4f ha" % luas_piksel_ha)
for f in hasil.getFeatures():
    baris = ["%s=%.2f" % (nm, f[nm] * luas_piksel_ha) for nm in hasil.fields().names() if nm.startswith("K")]
    print(f["NAMA_KPH"], "  ", "  ".join(baris))