#!/usr/bin/env
# -*- coding: utf-8 -*-


import os
import sys
import time

sys.path.append(r"C:\Program Files\QGIS 3.16\apps\qgis-ltr\python\plugins")
import math
import argparse
from qgis.core import *
from qgis.gui import *
from qgis.PyQt.QtGui import *
from qgis.PyQt.QtCore import *
from qgis.PyQt.QtWidgets import *
from processing.core.Processing import Processing


# 获取完整路径
def get_full_path():
    return os.path.split(sys.argv[0])[0]


# 获取参数
def get_args():
    print("argv = ", sys.argv[1:])
    parser = argparse.ArgumentParser(description='ArgUtils')
    parser.add_argument("-src", type=str, default=get_full_path(), required=False)
    parser.add_argument("-qgz", type=str, default=r"xyz.qgz", required=False)
    parser.add_argument("-file", type=str, default=r"D:\xyz\dem\dem.txt", required=False)
    parser.add_argument("-out", type=str, default=r"D:\xyz\dem\dem\astgtm2.tif", required=False)

    return parser.parse_args()


# 读取文本文件
def read_txt(filePath):
    f = open(filePath, encoding="utf-8")
    lines = f.readlines()
    f.close()

    for i in range(0, len(lines)):
        lines[i] = lines[i].replace('\n', '')

    return lines


# 加载图层
def load_layers(prj, args):
    for layer in prj.mapLayers().values():
        prj.removeMapLayer(layer)

    args.authid = None
    lines = read_txt(args.file)
    for i in range(0, len(lines)):
        if len(lines[i]) == 0:
            continue

        print("layer_" + str(i) + ": " + lines[i])
        layer = QgsRasterLayer(lines[i], "layer_" + str(i))
        if not layer.isValid() or layer.crs() is None:
            print("layer_" + str(i) + ": failed to load!")
            continue

        if len(prj.mapLayers()) == 0:
            args.authid = layer.crs().authid()
            print("authid: " + args.authid)
            prj.setCrs(layer.crs())

        prj.addMapLayer(layer)


# 获取参数
def get_ops(prj, args):
    layers = []
    for layer in prj.mapLayers().values():
        layers.append(layer.name())

    ops = {
        'INPUT': layers,
        'DATA_TYPE': 5,
        'OUTPUT': args.out,
        'NODATA_INPUT': 0,
        'NODATA_OUTPUT': 0,
        'OPTIONS': ''
    }
    print(ops)

    return ops


# 合并
def merge(prj, args):
    import processing

    ops = get_ops(prj, args)
    processing.run("gdal:merge", ops)


# 初始化
def init():
    # QgsApplication.setPrefixPath("C:\Program Files\QGIS 3.16", True)
    qgs = QgsApplication([], False)
    qgs.initQgis()
    Processing.initialize()

    args = get_args()
    prj = QgsProject.instance()
    prj.read(os.path.join(args.src, args.qgz))
    # prj.read(args.qgz)
    print("FileName: " + prj.fileName())

    load_layers(prj, args)
    merge(prj, args)

    qgs.exitQgis()


# main
if __name__ == '__main__':
    timer = time.time()
    init()

    print(f'耗时:{time.time() - timer:.2f}s')