# (C) Copyright 2005- ECMWF.

# Type of first fixed surface
codetable[1] typeOfFirstFixedSurface ('4.5.table',masterDir,localDir) : dump,edition_specific,string_type;
meta unitsOfFirstFixedSurface codetable_units(typeOfFirstFixedSurface) : dump;
meta nameOfFirstFixedSurface codetable_title(typeOfFirstFixedSurface) : dump;

# Scale factor of first fixed surface
signed[1] scaleFactorOfFirstFixedSurface = missing()  : can_be_missing,dump,edition_specific;

# Scaled value of first fixed surface
unsigned[4] scaledValueOfFirstFixedSurface = missing()  : can_be_missing,dump,edition_specific;

# Type of second fixed surface
codetable[1] typeOfSecondFixedSurface ('4.5.table',masterDir,localDir) = 255 : dump,edition_specific;
meta unitsOfSecondFixedSurface codetable_units(typeOfSecondFixedSurface) : dump;
meta nameOfSecondFixedSurface codetable_title(typeOfSecondFixedSurface) : dump;

# Scale factor of second fixed surface
signed[1] scaleFactorOfSecondFixedSurface = missing() : can_be_missing,dump,edition_specific;

# Scaled value of second fixed surface
unsigned[4] scaledValueOfSecondFixedSurface = missing() : can_be_missing,dump,edition_specific;

transient pressureUnits="hPa";

concept vertical.typeOfLevel (unknown,"typeOfLevelConcept.def",conceptsDir2,conceptsDir1);

alias levelType=typeOfFirstFixedSurface;

if (typeOfSecondFixedSurface == 255) {
  # Only one surface
  meta level g2level(typeOfFirstFixedSurface,
    scaleFactorOfFirstFixedSurface,
    scaledValueOfFirstFixedSurface,
    pressureUnits)  :dump;
  transient bottomLevel=level; # Do not use alias (see GRIB-725)
  transient topLevel=level;
} else {
  # Two surfaces
  meta topLevel g2level(typeOfFirstFixedSurface,
    scaleFactorOfFirstFixedSurface,
    scaledValueOfFirstFixedSurface,
    pressureUnits)  :dump;
  meta bottomLevel g2level(typeOfSecondFixedSurface,
    scaleFactorOfSecondFixedSurface,
    scaledValueOfSecondFixedSurface,
    pressureUnits)  :dump;
    alias level=topLevel;  # (see GRIB-725)

}
alias ls.level=level;
alias vertical.level=level;
alias vertical.bottomLevel=bottomLevel;
alias vertical.topLevel=topLevel;

alias extraDim=false;
if (defined(extraDimensionPresent)) {
    if (extraDimensionPresent) {
        alias extraDim=true;
    }
}
if (extraDim) {
    alias mars.levelist = dimension;
    alias mars.levtype = dimensionType;
} else {
    # ECC-1333: levtype should be read-only in GRIB2
    concept mars.levtype(unknown,"marsLevtypeConcept.def",conceptsDir2,conceptsDir1):no_copy, read_only;
    # GRIB-372: levelist alias does not pertain to surface parameters
    transient tempLevtype = levtype; # Faster to copy the concept so we evaluate it once
    # See GRIB-74 why we store the pressureUnits in a transient
    transient tempPressureUnits=pressureUnits;
    # Same as typeOfLevel != "surface" but much quicker to evaluate
    # than via the concept
    if ( ! ((typeOfFirstFixedSurface == 1 && typeOfSecondFixedSurface == 255) || tempLevtype is "sfc" || tempLevtype is "o2d")) {
        if (tempPressureUnits is "Pa") {
            meta marsLevel scale(level,one,hundred) : read_only;
            alias mars.levelist=marsLevel;
        } else {
            alias mars.levelist = level;
        }
    }
}

# See ECC-854, ECC-1435, ECC-1451, ECC-1462
if( (typeOfFirstFixedSurface == 151 && typeOfSecondFixedSurface == 151) ||
    (typeOfFirstFixedSurface == 152 && typeOfSecondFixedSurface == 152) ||
    (typeOfFirstFixedSurface == 168 && typeOfSecondFixedSurface == 168) ||
    (typeOfFirstFixedSurface == 114 && typeOfSecondFixedSurface == 114) ) {
    alias mars.levelist = bottomLevel;
    alias ls.level = bottomLevel;
    alias vertical.level = bottomLevel;
}

alias ls.typeOfLevel=typeOfLevel;
