/**
 * @file Uri.cpp
 *
 * This module contains the implementation of the Uri::Uri class.
 *
 * © 2018 by Richard Walters
 */

#include <inttypes.h>
#include <string>
#include <Uri/Uri.hpp>
#include <vector>

namespace Uri {
    /**
     * This contains the private properties of a Uri instance.
     */
    struct Uri::Impl {
        /**
         * This is the "scheme" element of the URI.
         */
        std::string scheme;

        /**
         * This is the "host" element of the URI.
         */
        std::string host;

        /**
         * This flag indicates whether or not the
         * URI includes a port number.
         */
        bool hasPort = false;

        /**
         * This is the port number element of the URI.
         */
        uint16_t port = 0;

        /**
         * This is the "path" element of the URI,
         * as a sequence of segments.
         */
        std::vector< std::string > path;
    };

    Uri::~Uri() = default;

    Uri::Uri()
        : impl_(new Impl)
    {
    }

    bool Uri::ParseFromString(const std::string& uriString) {
        // First parse the scheme.
        const auto schemeEnd = uriString.find(':');
        impl_->scheme = uriString.substr(0, schemeEnd);
        auto rest = uriString.substr(schemeEnd + 1);

        // Next parse the host.
        impl_->hasPort = false;
        if (rest.substr(0, 2) == "//") {
            const auto authorityEnd = rest.find('/', 2);
            const auto portDelimiter = rest.find(':');
            if (portDelimiter == std::string::npos) {
                impl_->host = rest.substr(2, authorityEnd - 2);
            } else {
                impl_->host = rest.substr(2, portDelimiter - 2);
                uint32_t newPort = 0;
                for (auto c: rest.substr(portDelimiter + 1, authorityEnd - portDelimiter - 1)) {
                    if (
                        (c < '0')
                        || (c > '9')
                    ) {
                        return false;
                    }
                    newPort *= 10;
                    newPort += (uint16_t)(c - '0');
                    if (
                        (newPort & ~((1 << 16) - 1)) != 0
                    ) {
                        return false;
                    }
                }
                impl_->port = (uint16_t)newPort;
                impl_->hasPort = true;
            }
            rest = rest.substr(authorityEnd);
        } else {
            impl_->host.clear();
        }

        // Finally, parse the path.
        impl_->path.clear();
        if (rest == "/") {
            // Special case of a path that is empty but needs a single
            // empty-string element to indicate that it is absolute.
            impl_->path.push_back("");
        } else if (!rest.empty()) {
            for(;;) {
                auto pathDelimiter = rest.find('/');
                if (pathDelimiter == std::string::npos) {
                    impl_->path.push_back(rest);
                    break;
                } else {
                    impl_->path.emplace_back(
                        rest.begin(),
                        rest.begin() + pathDelimiter
                    );
                    rest = rest.substr(pathDelimiter + 1);
                }
            }
        }
        return true;
    }

    std::string Uri::GetScheme() const {
        return impl_->scheme;
    }

    std::string Uri::GetHost() const {
        return impl_->host;
    }

    std::vector< std::string > Uri::GetPath() const {
        return impl_->path;
    }

    bool Uri::HasPort() const {
        return impl_->hasPort;
    }

    uint16_t Uri::GetPort() const {
        return impl_->port;
    }

}