openswmm_hotstart.h

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// SPDX-License-Identifier: Apache-2.0
//
// Copyright 2026 Caleb Buahin
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.


 
#ifndef OPENSWMM_ENGINE_HOTSTART_H
#define OPENSWMM_ENGINE_HOTSTART_H
 
#include "openswmm_engine.h"
 
#ifdef __cplusplus
extern "C" {
#endif

typedef void* SWMM_HotStart;

#define OPENSWMM_HOTSTART_MAGIC "OPENSWMM_HS_V1\0"

#define OPENSWMM_HOTSTART_VERSION 1
 
/* =========================================================================
 * [FILES] section — `SAVE HOTSTART` entry management (Slice BV-01)
 *
 * These functions manage the *static* list of scheduled hot-start save
 * entries that live in the `[FILES]` section of an `.inp` file
 * (`SimulationContext::hotstart_saves`).  They are distinct from the
 * runtime `swmm_hotstart_save()` function below, which writes a single
 * hot-start file at the current sim time.
 *
 * Each entry is a `{path, datetime, format}` triple.  A `datetime` of `0.0`
 * means "no datetime — save at end of run" (matches legacy semantics);
 * `format` is one of `SWMM_HOTSTART_FORMAT_*` (default AUTO).
 *
 * The legacy singular `swmm_files_set("HOTSTART_SAVE_PATH", …)` /
 * `_DATETIME` keys remain as slot-0 sugar.
 * ========================================================================= */

SWMM_ENGINE_API int swmm_hotstart_saves_count(SWMM_Engine engine, int* count);

SWMM_ENGINE_API int swmm_hotstart_saves_get_path(SWMM_Engine engine, int idx, char* buf,
                                                 int buflen);

SWMM_ENGINE_API int swmm_hotstart_saves_get_datetime(SWMM_Engine engine, int idx, double* datetime);

SWMM_ENGINE_API int swmm_hotstart_saves_set_path(SWMM_Engine engine, int idx, const char* path);

SWMM_ENGINE_API int swmm_hotstart_saves_set_datetime(SWMM_Engine engine, int idx, double datetime);

#define SWMM_HOTSTART_FORMAT_AUTO 0   
#define SWMM_HOTSTART_FORMAT_LEGACY 1 
#define SWMM_HOTSTART_FORMAT_NATIVE 2 

SWMM_ENGINE_API int swmm_hotstart_saves_get_format(SWMM_Engine engine, int idx, int* format);

SWMM_ENGINE_API int swmm_hotstart_saves_set_format(SWMM_Engine engine, int idx, int format);

#define SWMM_HOTSTART_OMITS_WATER_AGE 0x1        
#define SWMM_HOTSTART_OMITS_REACTION_SPECIES 0x2 
#define SWMM_HOTSTART_OMITS_AQUIFER 0x4          
#define SWMM_HOTSTART_OMITS_NODE_LIDS 0x8        

SWMM_ENGINE_API int swmm_hotstart_legacy_omits(SWMM_Engine engine, int* flags);

SWMM_ENGINE_API int swmm_hotstart_saves_add(SWMM_Engine engine, const char* path, double datetime);

SWMM_ENGINE_API int swmm_hotstart_saves_remove(SWMM_Engine engine, int idx);

SWMM_ENGINE_API int swmm_hotstart_saves_clear(SWMM_Engine engine);
 
/* =========================================================================
 * Create / save
 * ========================================================================= */

SWMM_ENGINE_API int swmm_hotstart_save(SWMM_Engine engine, const char* path);

SWMM_ENGINE_API const char* swmm_hotstart_last_io_error(void);
 
/* =========================================================================
 * Open / read
 * ========================================================================= */

SWMM_ENGINE_API int swmm_hotstart_open(const char* path, SWMM_HotStart* hs);
 
/* =========================================================================
 * Apply
 * ========================================================================= */

SWMM_ENGINE_API int swmm_hotstart_apply(SWMM_Engine engine, SWMM_HotStart hs);
 
/* =========================================================================
 * Modify hot start data
 * ========================================================================= */

SWMM_ENGINE_API int swmm_hotstart_set_node_depth(SWMM_HotStart hs, const char* node_id,
                                                 double depth);

SWMM_ENGINE_API int swmm_hotstart_set_node_head(SWMM_HotStart hs, const char* node_id, double head);

SWMM_ENGINE_API int swmm_hotstart_set_link_flow(SWMM_HotStart hs, const char* link_id, double flow);

SWMM_ENGINE_API int swmm_hotstart_set_link_depth(SWMM_HotStart hs, const char* link_id,
                                                 double depth);

SWMM_ENGINE_API int swmm_hotstart_set_subcatch_runoff(SWMM_HotStart hs, const char* subcatch_id,
                                                      double runoff);
 
/* =========================================================================
 * Query hot start metadata
 * ========================================================================= */

SWMM_ENGINE_API int swmm_hotstart_get_sim_time(SWMM_HotStart hs, double* sim_time);

SWMM_ENGINE_API int swmm_hotstart_get_start_date(SWMM_HotStart hs, double* start_date);

SWMM_ENGINE_API int swmm_hotstart_get_crs(SWMM_HotStart hs, char* buf, int buflen);

SWMM_ENGINE_API int swmm_hotstart_node_count(SWMM_HotStart hs);

SWMM_ENGINE_API int swmm_hotstart_link_count(SWMM_HotStart hs);
 
/* =========================================================================
 * Warning access (populated after swmm_hotstart_apply())
 * ========================================================================= */

SWMM_ENGINE_API int swmm_hotstart_warning_count(SWMM_HotStart hs);

SWMM_ENGINE_API const char* swmm_hotstart_warning(SWMM_HotStart hs, int index);
 
/* =========================================================================
 * Close
 * ========================================================================= */

SWMM_ENGINE_API int swmm_hotstart_close(SWMM_HotStart hs);
 
#ifdef __cplusplus
} /* extern "C" */
#endif
 
#endif /* OPENSWMM_ENGINE_HOTSTART_H */