odm/include/HYCOM.h

#pragma once
#include "DataAdapters/ncfilealt.h"
#include "ParseArgs.h"
#include "mdatetime.h"
#include "simple2ddata.h"
#include "specfunc.h"
#include <memory>
#include <regex.h>
#include <set>
#include <stdlib.h>
#include <sys/types.h>

using michlib::Ceil;
using michlib::errmessage;
using michlib::Floor;
using michlib::GPL;
using michlib::int2;
using michlib::MDateTime;
using michlib::NCFileA;
using michlib::ToGeoDomainPos;

class HYCOMData
{
 enum Type
 {
  TYPE_UNKNOWN,
  TYPE_REANALYSIS,
  TYPE_HINDCAST,
  TYPE_FORECAST
 };

 struct Parameters: public BaseParameters
 {
  size_t  xb, yb, xe, ye, layer;
  MString varname;
  virtual ~Parameters() override = default;
 };

 std::vector<NCFileA>   nc;
 std::vector<MString>   urls;
 std::vector<real>      depths;
 std::vector<MDateTime> times;
 size_t                 nx, ny;
 real                   lonb, latb, lone, late;
 real                   lonstep, latstep;
 Type                   type = TYPE_UNKNOWN;

 public:
 using Data = Simple2DData;

 private:
 template<class DataType> Data ReadVarRaw(const NCFileA& f, const MString& name, size_t i, bool nodepth, const Parameters* p) const
 {
  real     unitmul = 1.0;
  DataType fill;
  real     offset = 0.0, scale = 1.0;

  {
   auto a_fill   = f.A<DataType>(name, "_FillValue");
   auto a_offset_d = f.A<double>(name, "add_offset");
   auto a_scale_d  = f.A<double>(name, "scale_factor");
   auto a_offset_f = f.A<float>(name, "add_offset");
   auto a_scale_f  = f.A<float>(name, "scale_factor");
   if(!a_fill) return Data();
   fill = a_fill;
   if(a_offset_d) offset = a_offset_d;
   if(a_scale_d) scale = a_scale_d;
   if(a_offset_f) offset = a_offset_f;
   if(a_scale_f) scale = a_scale_f;
  }

  auto unit = f.A<MString>(name, "units");
  if(unit && (unit.Get() == "m s-1" || unit.Get() == "m/s")) unitmul = 100.0;

  Data data((p->xb < p->xe) ? (p->xe - p->xb + 1) : (nx + p->xe - p->xb + 1), p->ye - p->yb + 1, Lon(p->xb), Lat(p->yb), lonstep, latstep);

  if(p->xb < p->xe)
  {
   auto var = nodepth ? f.V<DataType>(name, {"lon", p->xb, p->xe - p->xb + 1}, {"lat", p->yb, p->ye - p->yb + 1}, {"time", i, 1})
                      : f.V<DataType>(name, {"lon", p->xb, p->xe - p->xb + 1}, {"lat", p->yb, p->ye - p->yb + 1}, {"time", i, 1}, {"depth", p->layer, 1});

   if(!var) return Data();
   if(var.DimLen(0) != data.Nx() || var.DimLen(1) != data.Ny()) return Data();

   for(size_t ix = 0; ix < var.DimLen(0); ix++)
    for(size_t iy = 0; iy < var.DimLen(1); iy++)
    {
     DataType v   = var(ix, iy);
     data(ix, iy) = (v == fill) ? Data::Fillval() : ((v * scale + offset) * unitmul);
    }
  }
  else
  {
   auto var1 = nodepth ? f.V<DataType>(name, {"lon", p->xb}, {"lat", p->yb, p->ye - p->yb + 1}, {"time", i, 1})
                       : f.V<DataType>(name, {"lon", p->xb}, {"lat", p->yb, p->ye - p->yb + 1}, {"time", i, 1}, {"depth", p->layer, 1});
   auto var2 = nodepth ? f.V<DataType>(name, {"lon", 0, p->xe + 1}, {"lat", p->yb, p->ye - p->yb + 1}, {"time", i, 1})
                       : f.V<DataType>(name, {"lon", 0, p->xe + 1}, {"lat", p->yb, p->ye - p->yb + 1}, {"time", i, 1}, {"depth", p->layer, 1});
   if(!(var1 && var2)) return Data();
   if((var1.DimLen(0) + var2.DimLen(0)) != data.Nx() || var1.DimLen(1) != data.Ny() || var2.DimLen(1) != data.Ny()) return Data();
   for(size_t ix = 0; ix < var1.DimLen(0); ix++)
    for(size_t iy = 0; iy < var1.DimLen(1); iy++)
    {
     DataType v   = var1(ix, iy);
     data(ix, iy) = (v == fill) ? Data::Fillval() : ((v * scale + offset) * unitmul);
    }
   for(size_t ix = 0; ix < var2.DimLen(0); ix++)
    for(size_t iy = 0; iy < var2.DimLen(1); iy++)
    {
     DataType v                    = var2(ix, iy);
     data(ix + var1.DimLen(0), iy) = (v == fill) ? Data::Fillval() : ((v * scale + offset) * unitmul);
    }
  }
  return data;
 }

 static MString VName2IName(const MString& vname)
 {
  if(vname == "temp") return "water_temp";
  if(vname == "sal") return "salinity";
  if(vname == "ssh") return "surf_el";
  return "";
 }

 public:
 Data Read(const BaseParameters* ip, size_t i) const
 {
  if(!isOk()) return Data();
  bool nodepth = false;

  auto    p    = dynamic_cast<const struct Parameters*>(ip);
  MString name = VName2IName(p->varname);
  for(const auto& f: nc)
  {
   auto head = f.Header();
   for(const auto& v: head.Variables())
    if(v.Name() == name)
    {
     if(v.Dimensions().size() == 3) nodepth = true;
     if(v.Type().Id() == NC_SHORT) return ReadVarRaw<int2>(f, name, i, nodepth, p);
     if(v.Type().Id() == NC_FLOAT) return ReadVarRaw<float>(f, name, i, nodepth, p);
    }
  }
  return Data();
 }

 bool HasVar(const MString vname) const
 {
  MString name = VName2IName(vname);
  if(name == "") return false;

  for(const auto& f: nc)
  {
   auto head = f.Header();
   for(const auto& v: head.Variables())
    if(v.Name() == name) return true;
  }
  return false;
 }

 public:
 HYCOMData() = default;

 // TODO: RetVal
 MString Open(const CLArgs& args)
 {
  MString dataset = args.contains("dataset") ? args.at("dataset") : "Forecast";

  nc.clear();

  if(dataset == "Forecast")
  {
   urls = {"https://tds.hycom.org/thredds/dodsC/GLBy0.08/expt_93.0/FMRC/GLBy0.08_930_FMRC_best.ncd"};
   type = TYPE_FORECAST;
  }
  else if(dataset == "Hindcast")
  {
   urls = {"https://tds.hycom.org/thredds/dodsC/GLBy0.08/expt_93.0"};
   type = TYPE_HINDCAST;
  }
  else if(dataset == "Reanalysis")
  {
   urls.clear();
   for(size_t i = 1994; i <= 2015; i++) urls.push_back("https://tds.hycom.org/thredds/dodsC/GLBv0.08/expt_53.X/data/" + MString(i));
   type = TYPE_REANALYSIS;
  }
  else
   return "Unknown dataset: " + dataset;

  nc.resize(urls.size());
  for(size_t i = 0; i < urls.size(); i++)
  {
   nc[i].Reset(urls[i]+"#cache&noprefetch");
   if(!nc[i])
   {
    nc.clear();
    return "Can't connect to database";
   }
  }

  auto rdepths = nc[0].V<double>("depth");
  if(!rdepths)
  {
   nc.clear();
   return "Can't read depths";
  }
  depths.resize(rdepths.DimLen(0));
  for(size_t i = 0; i < depths.size(); i++) depths[i] = rdepths(i);

  auto timeD = nc[0].V<double>("time");
  auto timeF = nc[0].V<float>("time");
  if(!(timeD || timeF))
  {
   nc.clear();
   return "Can't read times";
  }

  MDateTime refdate;
  {
   auto units = nc[0].Attribute<MString>("time", "units");
   if(!units)
   {
    nc.clear();
    return "Can't read refdate";
   }
   MString rstr;
   auto    words = michlib::Split_on_words(units);
   auto    ci    = words.begin();
   if(ci != words.end()) ci++;              // skip "hours"
   if(ci != words.end()) ci++;              // skip "since"
   if(ci != words.end()) rstr = *ci;        // Day
   if(ci != words.end()) ci++;
   if(ci != words.end()) rstr += " " + *ci; // Hours
   if(!refdate.FromString(rstr))
   {
    nc.clear();
    return "Can't parse " + rstr + " to refdate";
   }
  }

  timeD ? times.resize(timeD.DimLen(0)) : times.resize(timeF.DimLen(0));
  for(size_t i = 0; i < times.size(); i++) times[i] = refdate + static_cast<time_t>(timeD ? timeD(i) : timeF(i)) * 3600;

  auto nlon = nc[0].D("lon");
  auto nlat = nc[0].D("lat");
  if(!(nlon && nlat))
  {
   nc.clear();
   return "Can't get number of longitudes/latitudes";
  }
  nx = nlon;
  ny = nlat;

  auto lons = nc[0].V<double>("lon");
  auto lats = nc[0].V<double>("lat");
  if(!(lons && lats))
  {
   nc.clear();
   return "Can't get longitudes/latitudes";
  }
  lonb    = lons(0);
  latb    = lats(0);
  lone    = lons(nx - 1);
  late    = lats(ny - 1);
  lonstep = (lone - lonb) / (nx - 1);
  latstep = (late - latb) / (ny - 1);

  return "";
 }

 MString Info() const
 {
  if(!isOk()) return "";
  MString d;
  for(size_t i = 0; i < NDepths(); i++) d += MString(" ") + "(" + i + " " + Depth(i) + ")";

  std::set<MString> vars;
  for(const auto& f: nc)
  {
   auto head = f.Header();
   for(const auto& v: head.Variables())
   {
    if(v.Name() == "water_temp") vars.emplace("temp");
    if(v.Name() == "salinity") vars.emplace("sal");
    if(v.Name() == "surf_el") vars.emplace("ssh");
   }
  }
  MString svars;
  {
   bool first = true;
   for(const auto& v: vars)
   {
    svars += (first ? "" : ", ") + v;
    first = false;
   }
  }

  // clang-format off
  return
   "Dataset: " + Title() + "\n" +
   " Begin date: " + Time(0).ToString() + "\n" +
   " End date: " + Time(NTimes()-1).ToString() + "\n" +
   " Time step: " + Timestep() + " seconds\n" +
   " Time moments: " + NTimes() + "\n" +
   " Region: (" + lonb + " : " + lone + ") x (" + latb + " : " + late + ")\n" +
   " Grid: " + nx + "x" + ny + " (" + lonstep + " x " + latstep + ")\n" +
   " Depths:" + d + "\n" +
   " Supported variables: " + svars;
  // clang-format on
 }

 std::pair<const BaseParameters*, MString> Parameters(michlib_internal::ParameterListEx& pars, const CLArgs& args) const
 {
  std::unique_ptr<struct Parameters> ppar{new struct Parameters};

  if(!args.contains("var")) return {nullptr, "Variable not specified"};
  ppar->varname = args.at("var");
  if(!HasVar(ppar->varname)) return {nullptr, "Variable " + ppar->varname + " not exists in this dataset"};
  if(args.contains("layer")) ppar->layer = args.at("layer").ToInteger<size_t>();
  if(!args.contains("depth") && ppar->layer >= NDepths()) return {nullptr, MString("Layer ") + ppar->layer + " is too deep!"};
  real depth = args.contains("depth") ? args.at("depth").ToReal() : Depth(ppar->layer);

  if(!(args.contains("lonb") && args.contains("lone") && args.contains("latb") && args.contains("late"))) return {nullptr, "Region not specified (lonb, lone, latb, late)"};

  {
   real lon1 = ToGeoDomainPos(args.at("lonb").ToReal());
   real lon2 = ToGeoDomainPos(args.at("lone").ToReal());
   real lat1 = args.at("latb").ToReal();
   real lat2 = args.at("late").ToReal();

   ppar->yb = static_cast<size_t>(Floor((lat1 - latb) / latstep));
   ppar->ye = static_cast<size_t>(Ceil((lat2 - latb) / latstep));
   if(ppar->ye > ny - 1) ppar->ye = ny - 1;
   if(ppar->yb >= ppar->ye) return {nullptr, "Latb must be lesser then late"};

   ppar->xb = static_cast<size_t>(Floor((lon1 - lonb) / lonstep));
   ppar->xe = static_cast<size_t>(Ceil((lon2 - lonb) / lonstep));

   if(ppar->xb == ppar->xe) return {nullptr, "Lonb must be not equal late"};

   if(depth < 0.0 || depth > depths.back())
    ppar->layer = (depth < 0.0) ? 0 : (depths.size() - 1);
   else
    for(size_t i = 0; i < depths.size() - 1; i++)
    {
     if(depth >= depths[i] && depth <= depths[i + 1])
     {
      ppar->layer = (depth - depths[i] <= depths[i + 1] - depth) ? i : (i + 1);
      break;
     }
    }
  }

  pars.SetParameter("variable", ppar->varname);
  pars.SetParameter("depth", Depth(ppar->layer));
  pars.SetParameter("layer", ppar->layer);
  pars.SetParameter("dataset", Title());
  pars.SetParameter("lonb", Lon(ppar->xb));
  pars.SetParameter("latb", Lat(ppar->yb));
  pars.SetParameter("lone", Lon(ppar->xe));
  pars.SetParameter("late", Lat(ppar->ye));

  return {ppar.release(), ""};
 }

 MString Dump(const struct Parameters* ppar) const
 {
  // clang-format off
  return
   "Current settings:\n" + MString() +
   " Longitudes: from " + Lon(ppar->xb) + " (" + ppar->xb + ") to "+ Lon(ppar->xe) + " (" + ppar->xe + ")\n" +
   " Latitudes: from "  + Lat(ppar->yb) + " (" + ppar->yb + ") to "+ Lat(ppar->ye) + " (" + ppar->ye + ")\n" +
   " Depth: layer " + ppar->layer + ", depth " + Depth(ppar->layer) + " m\n";
  // clang-format on
 }

 real      Lon(size_t ix) const { return isOk() ? (lonb + ix * lonstep) : -1000.0; }
 real      Lat(size_t iy) const { return isOk() ? (latb + iy * latstep) : -1000.0; }
 real      Depth(size_t l) const { return isOk() ? depths[l] : -1000.0; }
 time_t    Timestep() const { return isOk() ? (times[1] - times[0]) : 0; }
 MDateTime Time(size_t i) const
 {
  if(!isOk() || i >= times.size()) return MDateTime();
  return times[i];
 }

 bool isOk() const { return nc.size() > 0; }
 explicit operator bool() const { return nc.size() > 0; }

 size_t NDepths() const { return depths.size(); }
 size_t NTimes() const { return times.size(); }

 MString Title() const
 {
  switch(type)
  {
  case(TYPE_REANALYSIS): return "GOFS 3.1: 41-layer HYCOM + NCODA Global 1/12 Reanalysis";
  case(TYPE_HINDCAST): return "GOFS 3.1: 41-layer HYCOM + NCODA Global 1/12 Analysis Hindcast";
  case(TYPE_FORECAST): return "GOFS 3.1: 41-layer HYCOM + NCODA Global 1/12 Analysis Forecast";
  default: return "No title";
  }
 }

 static real Fillval() { return Data::Fillval(); }
};