north.py

# -*- coding: utf-8 -*-

from operator import itemgetter
from PyQt5.QtCore import QCoreApplication

from qgis.core import (QgsFeatureSink,
                       QgsProcessing,
                       QgsProcessingAlgorithm,
                       QgsProcessingParameterFeatureSink,
                       QgsProcessingParameterNumber,
                       QgsProcessingParameterFeatureSource
)
import processing

class QNorth(QgsProcessingAlgorithm):

    INPUT = 'INPUT'
    NUMBER = 'NUMBER'
    OUTPUT = 'OUTPUT'

    def init(self):
        super().__init__()

    def createInstance(self):
        return QNorth()

    def name(self):
        return 'qnorth'

    def tr(self, text):
        return QCoreApplication.translate("qnorth", text)

    def displayName(self):
        return 'QNorth'

    def group(self):
        return 'My Scripts'

    def groupId(self):
        return 'myscripts'

    def initAlgorithm(self, config = None):

        self.addParameter(QgsProcessingParameterFeatureSource(
            self.INPUT,
            "Input layer",
            [QgsProcessing.TypeVectorPoint]
            )
        )
        
        self.addParameter(
            QgsProcessingParameterNumber(
            self.NUMBER,
            self.tr('Distance'),
            QgsProcessingParameterNumber.Integer,
            10
            )
        )

        self.addParameter(QgsProcessingParameterFeatureSink(
            self.OUTPUT,
            "North point",
            QgsProcessing.TypeVectorPoint
            )
        )


    def processAlgorithm(self, parameters, context, feedback):
        source = self.parameterAsSource(parameters,
            self.INPUT,
            context
        )
        
        distance = self.parameterAsInt(
            parameters,
            self.NUMBER,
            context
        )

        (sink, dest_id) = self.parameterAsSink(
            parameters,
            self.OUTPUT,
            context,
            source.fields(),
            source.wkbType(),
            source.sourceCrs()
        )

        coords = []
        for f in source.getFeatures():
            coords.append(f.geometry().asPoint())

        maximum = max(coords,key=itemgetter(1))

        features = source.getFeatures()
        for current, feat in enumerate(features):
            if feat.geometry().asPoint() == maximum:
                sink.addFeature(feat, QgsFeatureSink.FastInsert)
        
        param = {
            'INPUT': dest_id,
            'DISTANCE': distance,
            'SEGMENTS':5,
            'END_CAP_STYLE':0,
            'JOIN_STYLE':0,
            'MITER_LIMIT':2,
            'DISSOLVE':False,
            'OUTPUT':'memory:'
        }
        
        buffer = processing.run("native:buffer", param)
                
        


        return {self.OUTPUT: dest_id}