// Copyright (C) 2021-2023 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include <config.h>

#include <cc/command_interpreter.h>
#include <hooks/hooks.h>
#include <run_script.h>
#include <run_script_log.h>
#include <dhcp/option6_ia.h>
#include <dhcp/pkt4.h>
#include <dhcp/pkt6.h>
#include <dhcpsrv/cfgmgr.h>
#include <dhcpsrv/lease.h>
#include <dhcpsrv/subnet.h>
#include <process/daemon.h>

#include <string>

namespace isc {
namespace run_script {

RunScriptImplPtr impl;

} // namespace run_script
} // namespace isc

using namespace isc;
using namespace isc::asiolink;
using namespace isc::data;
using namespace isc::dhcp;
using namespace isc::hooks;
using namespace isc::process;
using namespace isc::run_script;
using namespace isc::util;
using namespace std;

// Functions accessed by the hooks framework use C linkage to avoid the name
// mangling that accompanies use of the C++ compiler as well as to avoid
// issues related to namespaces.
extern "C" {

/// @brief This function is called when the library is loaded.
///
/// @param handle library handle
/// @return 0 when initialization is successful, 1 otherwise
int load(LibraryHandle& handle) {
    try {
        // Make the hook library not loadable by d2 or ca.
        uint16_t family = CfgMgr::instance().getFamily();
        const string& proc_name = Daemon::getProcName();
        if (family == AF_INET) {
            if (proc_name != "kea-dhcp4") {
                isc_throw(isc::Unexpected, "Bad process name: " << proc_name
                          << ", expected kea-dhcp4");
            }
        } else {
            if (proc_name != "kea-dhcp6") {
                isc_throw(isc::Unexpected, "Bad process name: " << proc_name
                          << ", expected kea-dhcp6");
            }
        }

        impl.reset(new RunScriptImpl());
        impl->configure(handle);
    } catch (const exception& ex) {
        LOG_ERROR(run_script_logger, RUN_SCRIPT_LOAD_ERROR)
            .arg(ex.what());
        return (1);
    }

    LOG_INFO(run_script_logger, RUN_SCRIPT_LOAD);
    return (0);
}

/// @brief This function is called when the library is unloaded.
///
/// @return always 0.
int unload() {
    impl.reset();
    RunScriptImpl::setIOService(IOServicePtr());
    LOG_INFO(run_script_logger, RUN_SCRIPT_UNLOAD);
    return (0);
}

/// @brief dhcp4_srv_configured callout implementation.
///
/// @param handle callout handle.
int dhcp4_srv_configured(CalloutHandle& handle) {
    try {
        isc::asiolink::IOServicePtr io_service;
        handle.getArgument("io_context", io_service);
        if (!io_service) {
            // Should not happen!
            handle.setStatus(isc::hooks::CalloutHandle::NEXT_STEP_DROP);
            const string error("Error: io_context is null");
            handle.setArgument("error", error);
            return (1);
        }
        RunScriptImpl::setIOService(io_service);

    } catch (const exception& ex) {
        LOG_ERROR(run_script_logger, RUN_SCRIPT_LOAD_ERROR)
            .arg(ex.what());
        handle.setStatus(isc::hooks::CalloutHandle::NEXT_STEP_DROP);
        return (1);
    }
    return (0);
}

/// @brief dhcp6_srv_configured callout implementation.
///
/// @param handle callout handle.
int dhcp6_srv_configured(CalloutHandle& handle) {
    try {
        isc::asiolink::IOServicePtr io_service;
        handle.getArgument("io_context", io_service);
        if (!io_service) {
            // Should not happen!
            handle.setStatus(isc::hooks::CalloutHandle::NEXT_STEP_DROP);
            const string error("Error: io_context is null");
            handle.setArgument("error", error);
            return (1);
        }
        RunScriptImpl::setIOService(io_service);

    } catch (const exception& ex) {
        LOG_ERROR(run_script_logger, RUN_SCRIPT_LOAD_ERROR)
            .arg(ex.what());
        handle.setStatus(isc::hooks::CalloutHandle::NEXT_STEP_DROP);
        return (1);
    }
    return (0);
}

/// @brief handle @ref lease4_renew hook and set environment parameters for the
/// script.
/// IN: query4 subnet4 clientid hwaddr lease4
/// OUT: next_step
int lease4_renew(CalloutHandle& handle) {
    CalloutHandle::CalloutNextStep status = handle.getStatus();
    if (status == CalloutHandle::NEXT_STEP_DROP ||
        status == CalloutHandle::NEXT_STEP_SKIP) {
        return (0);
    }
    ProcessEnvVars vars;
    Pkt4Ptr pkt4;
    handle.getArgument("query4", pkt4);
    RunScriptImpl::extractPkt4(vars, pkt4, "QUERY4");
    Subnet4Ptr subnet4;
    handle.getArgument("subnet4", subnet4);
    RunScriptImpl::extractSubnet4(vars, subnet4, "SUBNET4");
    ClientIdPtr clientid;
    handle.getArgument("clientid", clientid);
    RunScriptImpl::extractClientId(vars, clientid, "PKT4_CLIENT_ID");
    HWAddrPtr hwaddr;
    handle.getArgument("hwaddr", hwaddr);
    RunScriptImpl::extractHWAddr(vars, hwaddr, "PKT4_HWADDR");
    Lease4Ptr lease4;
    handle.getArgument("lease4", lease4);
    RunScriptImpl::extractLease4(vars, lease4, "LEASE4");
    ProcessArgs args;
    args.push_back("lease4_renew");
    impl->runScript(args, vars);
    return (0);
}

/// @brief handle @ref lease4_expire hook and set environment parameters for the
/// script.
/// IN: lease4 remove_lease
/// OUT: next_step
int lease4_expire(CalloutHandle& handle) {
    CalloutHandle::CalloutNextStep status = handle.getStatus();
    if (status == CalloutHandle::NEXT_STEP_DROP ||
        status == CalloutHandle::NEXT_STEP_SKIP) {
        return (0);
    }
    ProcessEnvVars vars;
    Lease4Ptr lease4;
    handle.getArgument("lease4", lease4);
    RunScriptImpl::extractLease4(vars, lease4, "LEASE4");
    bool remove_lease;
    handle.getArgument("remove_lease", remove_lease);
    RunScriptImpl::extractBoolean(vars, remove_lease, "REMOVE_LEASE");
    ProcessArgs args;
    args.push_back("lease4_expire");
    impl->runScript(args, vars);
    return (0);
}

/// @brief handle @ref lease4_recover hook and set environment parameters for
/// the script.
/// IN: lease4
/// OUT: next_step
int lease4_recover(CalloutHandle& handle) {
    CalloutHandle::CalloutNextStep status = handle.getStatus();
    if (status == CalloutHandle::NEXT_STEP_DROP ||
        status == CalloutHandle::NEXT_STEP_SKIP) {
        return (0);
    }
    ProcessEnvVars vars;
    Lease4Ptr lease4;
    handle.getArgument("lease4", lease4);
    RunScriptImpl::extractLease4(vars, lease4, "LEASE4");
    ProcessArgs args;
    args.push_back("lease4_recover");
    impl->runScript(args, vars);
    return (0);
}

/// @brief handle @ref leases4_committed hook and set environment parameters for
/// the script.
/// IN: query4 leases4 deleted_leases4
/// OUT: next_step
int leases4_committed(CalloutHandle& handle) {
    CalloutHandle::CalloutNextStep status = handle.getStatus();
    if (status == CalloutHandle::NEXT_STEP_DROP ||
        status == CalloutHandle::NEXT_STEP_SKIP) {
        return (0);
    }
    ProcessEnvVars vars;
    Pkt4Ptr pkt4;
    handle.getArgument("query4", pkt4);
    RunScriptImpl::extractPkt4(vars, pkt4, "QUERY4");
    Lease4CollectionPtr leases4;
    handle.getArgument("leases4", leases4);
    RunScriptImpl::extractLeases4(vars, leases4, "LEASES4");
    Lease4CollectionPtr deleted_leases4;
    handle.getArgument("deleted_leases4", deleted_leases4);
    RunScriptImpl::extractLeases4(vars, deleted_leases4, "DELETED_LEASES4");
    ProcessArgs args;
    args.push_back("leases4_committed");
    impl->runScript(args, vars);
    return (0);
}

/// @brief handle @ref lease4_release hook and set environment parameters for
/// the script.
/// IN: query4 lease4
/// OUT: next_step
int lease4_release(CalloutHandle& handle) {
    CalloutHandle::CalloutNextStep status = handle.getStatus();
    if (status == CalloutHandle::NEXT_STEP_DROP ||
        status == CalloutHandle::NEXT_STEP_SKIP) {
        return (0);
    }
    ProcessEnvVars vars;
    Pkt4Ptr pkt4;
    handle.getArgument("query4", pkt4);
    RunScriptImpl::extractPkt4(vars, pkt4, "QUERY4");
    Lease4Ptr lease4;
    handle.getArgument("lease4", lease4);
    RunScriptImpl::extractLease4(vars, lease4, "LEASE4");
    ProcessArgs args;
    args.push_back("lease4_release");
    impl->runScript(args, vars);
    return (0);
}

/// @brief handle @ref lease4_decline hook and set environment parameters for
/// the script.
/// IN: query4 lease4
/// OUT: next_step
int lease4_decline(CalloutHandle& handle) {
    CalloutHandle::CalloutNextStep status = handle.getStatus();
    if (status == CalloutHandle::NEXT_STEP_DROP ||
        status == CalloutHandle::NEXT_STEP_SKIP) {
        return (0);
    }
    ProcessEnvVars vars;
    Pkt4Ptr pkt4;
    handle.getArgument("query4", pkt4);
    RunScriptImpl::extractPkt4(vars, pkt4, "QUERY4");
    Lease4Ptr lease4;
    handle.getArgument("lease4", lease4);
    RunScriptImpl::extractLease4(vars, lease4, "LEASE4");
    ProcessArgs args;
    args.push_back("lease4_decline");
    impl->runScript(args, vars);
    return (0);
}

/// @brief handle @ref lease6_renew hook and set environment parameters for the
/// script.
/// IN: query6 lease6 ia_na/ia_pd
/// OUT: next_step
int lease6_renew(CalloutHandle& handle) {
    CalloutHandle::CalloutNextStep status = handle.getStatus();
    if (status == CalloutHandle::NEXT_STEP_DROP ||
        status == CalloutHandle::NEXT_STEP_SKIP) {
        return (0);
    }
    ProcessEnvVars vars;
    Pkt6Ptr pkt6;
    handle.getArgument("query6", pkt6);
    RunScriptImpl::extractPkt6(vars, pkt6, "QUERY6");
    Lease6Ptr lease6;
    handle.getArgument("lease6", lease6);
    RunScriptImpl::extractLease6(vars, lease6, "LEASE6");
    Option6IAPtr option6IA;
    if (lease6->type_ == Lease::TYPE_NA) {
        handle.getArgument("ia_na", option6IA);
    } else {
        handle.getArgument("ia_pd", option6IA);
    }
    RunScriptImpl::extractOptionIA(vars, option6IA, "PKT6_IA");
    ProcessArgs args;
    args.push_back("lease6_renew");
    impl->runScript(args, vars);
    return (0);
}

/// @brief handle @ref lease6_rebind hook and set environment parameters for the
/// script.
/// IN: query6 lease6 ia_na/ia_pd
/// OUT: next_step
int lease6_rebind(CalloutHandle& handle) {
    CalloutHandle::CalloutNextStep status = handle.getStatus();
    if (status == CalloutHandle::NEXT_STEP_DROP ||
        status == CalloutHandle::NEXT_STEP_SKIP) {
        return (0);
    }
    ProcessEnvVars vars;
    Pkt6Ptr pkt6;
    handle.getArgument("query6", pkt6);
    RunScriptImpl::extractPkt6(vars, pkt6, "QUERY6");
    Lease6Ptr lease6;
    handle.getArgument("lease6", lease6);
    RunScriptImpl::extractLease6(vars, lease6, "LEASE6");
    Option6IAPtr option6IA;
    if (lease6->type_ == Lease::TYPE_NA) {
        handle.getArgument("ia_na", option6IA);
    } else {
        handle.getArgument("ia_pd", option6IA);
    }
    RunScriptImpl::extractOptionIA(vars, option6IA, "PKT6_IA");
    ProcessArgs args;
    args.push_back("lease6_rebind");
    impl->runScript(args, vars);
    return (0);
}

/// @brief handle @ref lease6_expire hook and set environment parameters for the
/// script.
/// IN: lease6 remove_lease
/// OUT: next_step
int lease6_expire(CalloutHandle& handle) {
    CalloutHandle::CalloutNextStep status = handle.getStatus();
    if (status == CalloutHandle::NEXT_STEP_DROP ||
        status == CalloutHandle::NEXT_STEP_SKIP) {
        return (0);
    }
    ProcessEnvVars vars;
    Lease6Ptr lease6;
    handle.getArgument("lease6", lease6);
    RunScriptImpl::extractLease6(vars, lease6, "LEASE6");
    bool remove_lease;
    handle.getArgument("remove_lease", remove_lease);
    RunScriptImpl::extractBoolean(vars, remove_lease, "REMOVE_LEASE");
    ProcessArgs args;
    args.push_back("lease6_expire");
    impl->runScript(args, vars);
    return (0);
}

/// @brief handle @ref lease6_recover hook and set environment parameters for
/// the script.
/// IN: lease6
/// OUT: next_step
int lease6_recover(CalloutHandle& handle) {
    CalloutHandle::CalloutNextStep status = handle.getStatus();
    if (status == CalloutHandle::NEXT_STEP_DROP ||
        status == CalloutHandle::NEXT_STEP_SKIP) {
        return (0);
    }
    ProcessEnvVars vars;
    Lease6Ptr lease6;
    handle.getArgument("lease6", lease6);
    RunScriptImpl::extractLease6(vars, lease6, "LEASE6");
    ProcessArgs args;
    args.push_back("lease6_recover");
    impl->runScript(args, vars);
    return (0);
}

/// @brief handle @ref leases6_committed hook and set environment parameters for
/// the script.
/// IN: query6 leases6 deleted_leases6
/// OUT: next_step
int leases6_committed(CalloutHandle& handle) {
    CalloutHandle::CalloutNextStep status = handle.getStatus();
    if (status == CalloutHandle::NEXT_STEP_DROP ||
        status == CalloutHandle::NEXT_STEP_SKIP) {
        return (0);
    }
    ProcessEnvVars vars;
    Pkt6Ptr pkt6;
    handle.getArgument("query6", pkt6);
    RunScriptImpl::extractPkt6(vars, pkt6, "QUERY6");
    Lease6CollectionPtr leases6;
    handle.getArgument("leases6", leases6);
    RunScriptImpl::extractLeases6(vars, leases6, "LEASES6");
    Lease6CollectionPtr deleted_leases6;
    handle.getArgument("deleted_leases6", deleted_leases6);
    RunScriptImpl::extractLeases6(vars, deleted_leases6, "DELETED_LEASES6");
    ProcessArgs args;
    args.push_back("leases6_committed");
    impl->runScript(args, vars);
    return (0);
}

/// @brief handle @ref lease6_release hook and set environment parameters for
/// the script.
/// IN: query6 lease6
/// OUT: next_step
int lease6_release(CalloutHandle& handle) {
    CalloutHandle::CalloutNextStep status = handle.getStatus();
    if (status == CalloutHandle::NEXT_STEP_DROP ||
        status == CalloutHandle::NEXT_STEP_SKIP) {
        return (0);
    }
    ProcessEnvVars vars;
    Pkt6Ptr pkt6;
    handle.getArgument("query6", pkt6);
    RunScriptImpl::extractPkt6(vars, pkt6, "QUERY6");
    Lease6Ptr lease6;
    handle.getArgument("lease6", lease6);
    RunScriptImpl::extractLease6(vars, lease6, "LEASE6");
    ProcessArgs args;
    args.push_back("lease6_release");
    impl->runScript(args, vars);
    return (0);
}

/// @brief handle @ref lease6_decline hook and set environment parameters for
/// the script.
/// IN: query6 lease6
/// OUT: next_step
int lease6_decline(CalloutHandle& handle) {
    CalloutHandle::CalloutNextStep status = handle.getStatus();
    if (status == CalloutHandle::NEXT_STEP_DROP ||
        status == CalloutHandle::NEXT_STEP_SKIP) {
        return (0);
    }
    ProcessEnvVars vars;
    Pkt6Ptr pkt6;
    handle.getArgument("query6", pkt6);
    RunScriptImpl::extractPkt6(vars, pkt6, "QUERY6");
    Lease6Ptr lease6;
    handle.getArgument("lease6", lease6);
    RunScriptImpl::extractLease6(vars, lease6, "LEASE6");
    ProcessArgs args;
    args.push_back("lease6_decline");
    impl->runScript(args, vars);
    return (0);
}

/// @brief This function is called to retrieve the multi-threading compatibility.
///
/// @return 1 which means compatible with multi-threading.
int multi_threading_compatible() {
    return (1);
}

} // end extern "C"