// heat-flow FFI body: opaque doc, pipeline, mesh accessors. delegates to hsolv's Chsolvdoc.

#include "../hsolv/StdAfx.h"
#include "../hsolv/hsolvDlg.h"
#include "../hsolv/mesh.h"
#include "../hsolv/spars.h"
#include "../hsolv/hsolvdoc.h"

#include "femm_heat.h"

#include <cstdio>
#include <cstdarg>
#include <string>

// stub view: math files reference TheView globally, math methods call SetPos/SetDlgItemText/InvalidateRect on it.
static ChsolvDlg s_stub_view;
ChsolvDlg* TheView = &s_stub_view;

// math files declare and call these for error reporting.
int MsgBox(const char* fmt, ...) {
    va_list ap; va_start(ap, fmt);
    std::vfprintf(stderr, fmt, ap);
    std::fputc('\n', stderr);
    va_end(ap);
    return 0;
}
int MsgBox(const std::string& s) {
    std::fprintf(stderr, "%s\n", s.c_str());
    return 0;
}

// referenced by hsolv/main.cpp's old_main wait loop; main.cpp itself is not linked here.
inline bool IsWindow(void*) { return true; }

struct FemmHeatDoc {
    Chsolvdoc          doc;
    FemmHeatProgressFn cb = nullptr;
    void*              user = nullptr;
    std::string        path_buf;
};

extern "C" {

FemmHeatDoc* femm_heat_doc_new(void) {
    auto* d = new FemmHeatDoc();
    d->doc.TheView = &s_stub_view;
    return d;
}

void femm_heat_doc_free(FemmHeatDoc* d) {
    delete d;
}

void femm_heat_doc_set_progress(FemmHeatDoc* d, FemmHeatProgressFn fn, void* user) {
    if (!d) return;
    d->cb = fn;
    d->user = user;
}

int femm_heat_doc_load_feh(FemmHeatDoc* d, const char* path) {
    if (!d || !path) return 0;
    d->path_buf = path;
    d->doc.PathName = const_cast<char*>(d->path_buf.c_str());
    return d->doc.OnOpenDocument() ? 1 : 0;
}

int femm_heat_doc_load_mesh(FemmHeatDoc* d) {
    return (d && d->doc.LoadMesh()) ? 1 : 0;
}

// loads the previous temperature solution referenced by the .feh.
int femm_heat_doc_load_prev(FemmHeatDoc* d) {
    return (d && d->doc.LoadPrev()) ? 1 : 0;
}

int femm_heat_doc_renumber(FemmHeatDoc* d) {
    return (d && d->doc.Cuthill()) ? 1 : 0;
}

// allocates a real-valued CBigLinProb and runs AnalyzeProblem + WriteResults.
int femm_heat_doc_solve(FemmHeatDoc* d) {
    if (!d) return 0;
    CBigLinProb L;
    L.TheView   = &s_stub_view;
    L.Precision = d->doc.Precision;
    if (!L.Create(d->doc.NumNodes + d->doc.NumCircProps, d->doc.BandWidth)) return 0;
    if (!d->doc.AnalyzeProblem(L)) return 0;
    if (!d->doc.WriteResults(L)) return 0;
    return 1;
}

int femm_heat_doc_write_results(FemmHeatDoc* /*d*/, const char* /*out_path*/) {
    // results currently emitted inline by solve(); reserved hook for explicit output redirection.
    return 1;
}

int    femm_heat_doc_axisymmetric (const FemmHeatDoc* d) { return (d && d->doc.ProblemType) ? 1 : 0; }
double femm_heat_doc_depth        (const FemmHeatDoc* d) { return d ? d->doc.Depth     : 0.0; }
double femm_heat_doc_precision    (const FemmHeatDoc* d) { return d ? d->doc.Precision : 0.0; }
double femm_heat_doc_dt           (const FemmHeatDoc* d) { return d ? d->doc.dT        : 0.0; }

int  femm_heat_doc_num_nodes (const FemmHeatDoc* d) { return d ? d->doc.NumNodes : 0; }

void femm_heat_doc_node (const FemmHeatDoc* d, int i, double* x, double* y) {
    if (!d || !d->doc.meshnode) return;
    if (x) *x = d->doc.meshnode[i].x;
    if (y) *y = d->doc.meshnode[i].y;
}

int  femm_heat_doc_num_elements (const FemmHeatDoc* d) { return d ? d->doc.NumEls : 0; }

void femm_heat_doc_element (const FemmHeatDoc* d, int i, int* p0, int* p1, int* p2) {
    if (!d || !d->doc.meshele) return;
    if (p0) *p0 = d->doc.meshele[i].p[0];
    if (p1) *p1 = d->doc.meshele[i].p[1];
    if (p2) *p2 = d->doc.meshele[i].p[2];
}

int femm_heat_doc_num_materials  (const FemmHeatDoc* d) { return d ? d->doc.NumBlockProps : 0; }
int femm_heat_doc_num_boundaries (const FemmHeatDoc* d) { return d ? d->doc.NumLineProps  : 0; }
int femm_heat_doc_num_conductors (const FemmHeatDoc* d) { return d ? d->doc.NumCircProps  : 0; }

// field sampling is post-processor territory; not exposed by the solver alone.
double femm_heat_doc_field_at (const FemmHeatDoc* /*d*/, double /*x*/, double /*y*/, FemmHeatField /*c*/) {
    return 0.0;
}

}  // extern "C"