/******************************************************************************
 * Copyright (c) 2023, Howard Butler (info@hobu.co)
 *
 * All rights reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided
 *       with the distribution.
 *     * Neither the name of Hobu, Inc. or Flaxen Geo Consulting nor the
 *       names of its contributors may be used to endorse or promote
 *       products derived from this software without specific prior
 *       written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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#include "ExpressionFilter.hpp"

#include <pdal/util/ProgramArgs.hpp>
#include <pdal/util/Utils.hpp>
#include "./private/expr/ConditionalExpression.hpp"



#include <cctype>
#include <limits>
#include <map>
#include <string>
#include <vector>

namespace pdal
{

static StaticPluginInfo const s_info
{
    "filters.expression",
    "Pass only points given an expression",
    "http://pdal.io/stages/filters.expression.html"
};

CREATE_STATIC_STAGE(ExpressionFilter, s_info)

std::string ExpressionFilter::getName() const
{
    return s_info.name;
}

struct ExpressionFilter::Args
{
    std::vector<expr::ConditionalExpression> m_expressions;
    Arg *m_whereArg;
};


ExpressionFilter::ExpressionFilter() : m_args(new Args)
{}


ExpressionFilter::~ExpressionFilter()
{}


void ExpressionFilter::addArgs(ProgramArgs& args)
{
    m_args->m_whereArg = &args.add("expression",
        "Conditional expression describing points to be passed to this filter",
        m_args->m_expressions).setPositional();
}


void ExpressionFilter::prepared(PointTableRef table)
{
    for (auto& expression: m_args->m_expressions)
    {
        if (!expression.valid())
        {
            std::stringstream oss;
            oss << "The expression '" <<  expression
                << "' is invalid";
            throwError(oss.str());
        }

        auto status = expression.prepare(table.layout());
        if (!status)
            throwError("Invalid 'where': " + status.what());
    }
}


bool ExpressionFilter::processOne(PointRef& point)
{
    if (m_args->m_expressions.size() != 1)
        throwError("Streaming of expressions only works with a single expression");

    bool status = m_args->m_expressions[0].eval(point);
    return status;
}


PointViewSet ExpressionFilter::run(PointViewPtr inView)
{
    PointViewSet viewSet;
    if (!inView->size())
        return viewSet;

    // make a view for each one of our expressions

    std::vector<PointViewPtr> views;
    for (expr::ConditionalExpression& expr: m_args->m_expressions)
    {
        PointViewPtr outView = inView->makeNew();
        views.push_back(outView);
    }

    // eval our expression across each point for each view.
    // TODO: make this threaded
    for (PointRef point : *inView)
    {
        for (size_t i = 0; i < views.size(); i++)
        {
            auto& view = views[i];
            auto& expr = m_args->m_expressions[i];

            bool status = expr.eval(point);
            if (status)
                view->appendPoint(*inView.get(), point.pointId());
        }
    }

    for(auto& v: views)
        viewSet.insert(v);

    return viewSet;
}

} // namespace pdal
