#!/usr/bin/env python

#
# LSST Data Management System
# Copyright 2008-2015 LSST Corporation.
#
# This product includes software developed by the
# LSST Project (http://www.lsst.org/).
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the LSST License Statement and
# the GNU General Public License along with this program.  If not,
# see <http://www.lsstcorp.org/LegalNotices/>.
#

import os
import sys

import numpy as np

from lsst.utils import getPackageDir
import lsst.afw.table as afwTable
import lsst.afw.image as afwImage
import lsst.afw.display as afwDisplay
import lsst.meas.algorithms as measAlg
import lsst.pex.exceptions as pexExcept
from lsst.meas.algorithms.detection import SourceDetectionTask
from lsst.meas.base import SingleFrameMeasurementTask

afwDisplay.setDefaultMaskTransparency(75)


def loadData():
    """Prepare the data we need to run the example"""

    # Load sample input from disk
    try:
        mypath = getPackageDir("afwdata")
    except pexExcept.NotFoundError:
        print("Please setup afwdata and try again", file=sys.stderr)
        sys.exit(1)

    imFile = os.path.join(mypath, "CFHT", "D4", "cal-53535-i-797722_small_1.fits")

    exposure = afwImage.ExposureF(imFile)
    psf = measAlg.SingleGaussianPsf(21, 21, 2)
    exposure.setPsf(psf)

    im = exposure.getMaskedImage().getImage()
    im -= float(np.median(im.getArray()))

    return exposure


def run(display=False):
    exposure = loadData()
    schema = afwTable.SourceTable.makeMinimalSchema()
    #
    # Create the detection task
    #
    config = SourceDetectionTask.ConfigClass()
    config.thresholdPolarity = "both"
    config.background.isNanSafe = True
    config.thresholdValue = 3
    detectionTask = SourceDetectionTask(config=config, schema=schema)
    #
    # And the measurement Task
    #
    config = SingleFrameMeasurementTask.ConfigClass()
    config.plugins.names.clear()
    for plugin in ["base_SdssCentroid", "base_SdssShape", "base_CircularApertureFlux", "base_GaussianFlux"]:
        config.plugins.names.add(plugin)
    config.slots.psfFlux = None
    config.slots.apFlux = "base_CircularApertureFlux_3_0"

    measureTask = SingleFrameMeasurementTask(schema, config=config)

    #
    # Print the schema the configuration produced
    #
    print(schema)

    #
    # Create the output table
    #
    tab = afwTable.SourceTable.make(schema)
    #
    # Process the data
    #
    result = detectionTask.run(tab, exposure)

    sources = result.sources

    print("Found %d sources (%d +ve, %d -ve)" % (len(sources), result.fpSets.numPos, result.fpSets.numNeg))

    measureTask.run(sources, exposure)
    if display:                         # display image (see also --debug argparse option)
        frame = 1
        disp = afwDisplay.Display(frame=frame)
        disp.mtv(exposure)

        with disp.Buffering():
            for s in sources:
                xy = s.getCentroid()
                disp.dot('+', *xy, ctype=afwDisplay.CYAN if s.get("flags_negative") else afwDisplay.GREEN)
                disp.dot(s.getShape(), *xy, ctype=afwDisplay.RED)
                disp.dot('o', *xy, size=config.plugins["base_CircularApertureFlux"].radii[0],
                         ctype=afwDisplay.YELLOW)


if __name__ == "__main__":
    import argparse
    parser = argparse.ArgumentParser(description="Demonstrate the use of Source{Detection,Measurement}Task")

    parser.add_argument('--debug', '-d', action="store_true", help="Load debug.py?", default=False)
    parser.add_argument('--doDisplay', action="store_true", help="Display sources", default=False)

    args = parser.parse_args()

    if args.debug:
        try:
            import debug  # noqa F401
        except ImportError as e:
            print(e, file=sys.stderr)

    run(display=args.doDisplay)