odm/include/layereddata.h

#pragma once
#include "DataAdapters/ncfilealt.h"
#include "ParseArgs.h"
#include "mdatetime.h"
#include "simple2ddata.h"
#include <algorithm>
#include <memory>
#include <set>

using michlib::Ceil;
using michlib::DetGeoDomain;
using michlib::Floor;
using michlib::GPL;
using michlib::int2;
using michlib::MDateTime;
using michlib::MString;
using michlib::NCFileA;
using michlib::ToGeoDomain;

class LayeredData
{
 public:
 using Data = Simple2DData;

 private:
 class NC
 {
  MString                url;
  NCFileA                nc;
  std::vector<MDateTime> times;

  public:
  NC(MString&& newurl): url(std::move(newurl)) { nc.Reset(url + "#cache&noprefetch"); }

  MString ReadTimes()
  {
   if(!nc) return "File not open";
   auto time = nc.VR("time");
   if(!time) return "Can't read times";

   MDateTime refdate;
   {
    auto units = nc.Attribute<MString>("time", "units");
    if(!units) 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)) return "Can't parse " + rstr + " to refdate";
   }

   times.resize(time.DimLen(0));
   for(size_t i = 0; i < times.size(); i++) times[i] = refdate + static_cast<time_t>(time(i)) * 3600;
   return "";
  }

  const NCFileA* operator->() const { return &nc; }
  explicit operator bool() const { return nc; }
  MDateTime Begin() const { return times.front(); }
  MDateTime End() const { return times.back(); }

  const std::vector<MDateTime>& Times() const { return times; }
  size_t                        Index(MDateTime tm) const
  {
   if(tm < Begin() || tm > End()) return 0;
   size_t b = 0, e = times.size() - 1;
   if(tm == times[b]) return b + 1;
   if(tm == times[e]) return e + 1;
   while(e - b > 1)
   {
    size_t c = (e + b) / 2;
    if(tm == times[c]) return c + 1;
    if(tm > times[c])
     b = c;
    else
     e = c;
   }
   return 0;
  }
 };
 std::vector<NC>        nc;
 std::vector<real>      depths;
 std::vector<MDateTime> times;
 MString                lonname, latname;
 size_t                 nx, ny;
 real                   lonb, latb, lone, late;
 real                   lonstep, latstep;
 MString                title;

 class EnvVar
 {
  MString name, oldvalue;
  bool    activated, saved;

  public:
  EnvVar(): activated(false) {}
  ~EnvVar() { Deactivate(); }

  void Activate(const MString& var, const MString& val)
  {
   if(activated) Deactivate();
   name         = var;
   char* curval = getenv(name.Buf());
   if(nullptr == curval)
    saved = false;
   else
   {
    oldvalue = curval;
    saved    = true;
   }
   setenv(name.Buf(), val.Buf(), 1);
  }
  void Deactivate()
  {
   if(!activated) return;
   if(saved)
    setenv(name.Buf(), oldvalue.Buf(), 1);
   else
    unsetenv(name.Buf());
   activated = false;
  }
 };

 EnvVar proxy;

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

 // TODO: RetVal
 MString Open(const MString& dataset);

 void SetTitle(const MString& newtitle) { title = newtitle; }

 public:
 MString Info() const;

 std::pair<const BaseParameters*, MString> Parameters(michlib_internal::ParameterListEx& pars, const CLArgs& args) const;

 Data Read(const BaseParameters* ip, size_t i) const;

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

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

 real Depth(size_t l) const { return isOk() ? depths[l] : -1000.0; }

 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; }

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

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

 MDateTime Time(size_t i) const
 {
  if(!isOk() || i >= times.size()) return MDateTime();
  return times[i];
 }

 time_t Timestep() const { return isOk() ? (times[1] - times[0]) : 0; }

 MString Title() const { return title; }

 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
 }

 private:
 template<class DataType> Data ReadVarRaw(const NC& f, const MString& name, size_t i, bool nodepth, const struct Parameters* p) const;

 bool HaveVar(const MString vname) const
 {
  for(size_t i = 0; i < nc.size(); i++)
  {
   auto head = nc[i]->Header();
   for(const auto& v: head.Variables())
   {
    auto stname = nc[i]->A<MString>(v.Name(), "standard_name");
    if(!stname) continue;
    if(StName2Name(stname) == vname) return true;
   }
  }
  return false;
 }

 std::tuple<MString, size_t, size_t> VarNameLoc(const MString vname, MDateTime tm) const
 {
  for(size_t i = 0; i < nc.size(); i++)
  {
   auto head = nc[i]->Header();
   auto tind = nc[i].Index(tm);
   if(tind == 0) continue;
   for(const auto& v: head.Variables())
   {
    auto stname = nc[i]->A<MString>(v.Name(), "standard_name");
    if(!stname) continue;
    if(StName2Name(stname) == vname) return {v.Name(), i, tind - 1};
   }
  }
  return {"", 0, 0};
 }

 static MString StName2Name(const MString& stname)
 {
  if(stname == "sea_water_potential_temperature") return "temp";
  if(stname == "sea_water_temperature") return "temp";
  if(stname == "sea_water_salinity") return "sal";
  if(stname == "ocean_mixed_layer_thickness_defined_by_sigma_theta") return "mld";
  if(stname == "sea_surface_height_above_geoid") return "ssh";
  if(stname == "sea_surface_elevation") return "ssh";
  if(stname == "upward_sea_water_velocity") return "w";
  return "";
 }
};