// Copyright 2011 Google Inc.
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//
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// modification, are permitted provided that the following conditions are
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//
// * Redistributions of source code must retain the above copyright
//   notice, this list of conditions and the following disclaimer.
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//   notice, this list of conditions and the following disclaimer in the
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//   may be used to endorse or promote products derived from this software
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//
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#include "engine/context.hpp"

#include "utils/env.hpp"
#include "utils/format/macros.hpp"
#include "utils/fs/operations.hpp"
#include "utils/text/operations.ipp"

namespace fs = utils::fs;
namespace text = utils::text;


/// Internal implementation of a context.
struct engine::context::impl {
    /// The current working directory.
    fs::path _cwd;

    /// The environment variables.
    std::map< std::string, std::string > _env;

    /// Constructor.
    ///
    /// \param cwd_ The current working directory.
    /// \param env_ The environment variables.
    impl(const fs::path& cwd_,
         const std::map< std::string, std::string >& env_) :
        _cwd(cwd_),
        _env(env_)
    {
    }

    /// Equality comparator.
    ///
    /// \param other The object to compare to.
    ///
    /// \return True if the two objects are equal; false otherwise.
    bool
    operator==(const impl& other) const
    {
        return _cwd == other._cwd && _env == other._env;
    }
};


/// Constructs a new context.
///
/// \param cwd_ The current working directory.
/// \param env_ The environment variables.
engine::context::context(const fs::path& cwd_,
                         const std::map< std::string, std::string >& env_) :
    _pimpl(new impl(cwd_, env_))
{
}


/// Destructor.
engine::context::~context(void)
{
}


/// Constructs a new context based on the current environment.
engine::context
engine::context::current(void)
{
    return context(fs::current_path(), utils::getallenv());
}


/// Returns the current working directory of the context.
///
/// \return A path.
const fs::path&
engine::context::cwd(void) const
{
    return _pimpl->_cwd;
}


/// Returns the environment variables of the context.
///
/// \return A variable name to variable value mapping.
const std::map< std::string, std::string >&
engine::context::env(void) const
{
    return _pimpl->_env;
}


/// Equality comparator.
///
/// \param other The other object to compare this one to.
///
/// \return True if this object and other are equal; false otherwise.
bool
engine::context::operator==(const context& other) const
{
    return *_pimpl == *other._pimpl;
}


/// Inequality comparator.
///
/// \param other The other object to compare this one to.
///
/// \return True if this object and other are different; false otherwise.
bool
engine::context::operator!=(const context& other) const
{
    return !(*this == other);
}


/// Injects the object into a stream.
///
/// \param output The stream into which to inject the object.
/// \param object The object to format.
///
/// \return The output stream.
std::ostream&
engine::operator<<(std::ostream& output, const context& object)
{
    output << F("context{cwd=%s, env=[")
        % text::quote(object.cwd().str(), '\'');

    const std::map< std::string, std::string >& env = object.env();
    bool first = true;
    for (std::map< std::string, std::string >::const_iterator
             iter = env.begin(); iter != env.end(); ++iter) {
        if (!first)
            output << ", ";
        first = false;

        output << F("%s=%s") % (*iter).first
            % text::quote((*iter).second, '\'');
    }

    output << "]}";
    return output;
}