[repo]
kind = "recipe"

[recipe]
description = "Generate an 'SHO' (golden/blue Hubble palette) from HaOiii (and optionally SiiOiii) data. Green is the real Sii channel when present, otherwise a synthetic Ha/OIII blend."

[[stages]]

name = "palette_sho"
description = "SHO palette: R=Ha, G=Sii-or-synthetic, B=OIII"
tool.name = "siril"
#role = "palette"

# Channels are selected out of the prior stage outputs by filename suffix
# (_Ha / _OIII / _Sii). We load them by absolute path and re-save under canonical
# names so Siril PixelMath ($Ha$ / $OIII$) can reference them.
#
# The green line is a single template expression: if a _Sii channel is present it
# expands to `load <sii>` (real Sii on green), otherwise to a `pm` blend of Ha+OIII.
script = '''
    # Bring the noise-reduced Ha and OIII channels in under canonical names.
    # Rescale each to 0..1 so all three channels enter rgbcomp on the same
    # footing (otherwise Ha/OIII dominate green and the result goes magenta).
    load {[str(p) for p in input["ha"].full_paths if "_Ha" in str(p)][0]}
    save Ha
    pm "$Ha$" -rescale 0.0 1.0
    save Ha
    load {[str(p) for p in input["oiii"].full_paths if "_OIII" in str(p)][0]}
    save OIII
    pm "$OIII$" -rescale 0.0 1.0
    save OIII

    # Green channel: use the real Sii channel if present, otherwise synthesize one from Ha+OIII
    {'load ' + [str(p) for p in input["sii"].full_paths if "_Sii" in str(p)][0] if [str(p) for p in input["sii"].full_paths if "_Sii" in str(p)] else 'pm "$Ha$ * ' + str(parameters.ha_weight) + ' + $OIII$ * ' + str(parameters.oiii_weight) + '" -rescale 0.0 1.0'}
    save SynGreen
    # Rescale Sii to 0..1 like Ha/OIII above. Without this the raw Sii
    # background (~5e-4) is ~20x brighter than the rescaled Ha/OIII
    # backgrounds (~2e-5) and the composite goes bright green.
    pm "$SynGreen$" -rescale 0.0 1.0
    save SynGreen

    # Merge into an SHO image: R=Ha, G=SynGreen (Sii or synthetic), B=OIII
    rgbcomp Ha SynGreen OIII -out=results

    # Remove the residual magenta/purple cast. SCNR (rmgreen) only removes
    # *green*, so we invert (magenta -> green), run rmgreen, then invert back.
    pm "1 - $results$"
    rmgreen
    save results
    pm "1 - $results$"
    save results

    # Move to the final output location
    load results
    save "{output.full_paths[0]}"
    '''

[[stages.inputs]]
kind = "job"
name = "ha"
# The Ha channel is required.  Keep this requirement on its own input block so
# min_count applies to this channel rather than to each multiplexed upstream
# task (which contains only one channel).
after = "denoise" # the role name: whichever denoiser will actually run

[[stages.inputs.requires]]
kind = "metadata"
name = "filter"
value = ["HaOiii", "SiiOiii"]

[[stages.inputs.requires]]
kind = "filename"
value = "_Ha"

[[stages.inputs.requires]]
kind = "min_count"
value = 1

[[stages.inputs]]
kind = "job"
name = "oiii"
# OIII is also required, but has its own min_count requirement.
after = "denoise" # the role name: whichever denoiser will actually run

[[stages.inputs.requires]]
kind = "metadata"
name = "filter"
value = ["HaOiii", "SiiOiii"]

[[stages.inputs.requires]]
kind = "filename"
value = "_OIII"

[[stages.inputs.requires]]
kind = "min_count"
value = 1

[[stages.inputs]]
kind = "job"
name = "sii"
# Sii is optional: without min_count, an absent matching input is represented
# by an empty FileInfo and the script synthesizes green instead.
after = "denoise" # the role name: whichever denoiser will actually run
optional = true

[[stages.inputs.requires]]
kind = "metadata"
name = "filter"
value = ["SiiOiii"]

[[stages.inputs.requires]]
kind = "filename"
value = "_Sii"

[[stages.outputs]]
kind = "processed"
name = ["SHO.fits"]

[[stages.parameters]]
name = "ha_weight"
default = 0.4                                                              # Value used if not overriden
description = "Ha contribution when synthesizing the green channel (0..1)"

[[stages.parameters]]
name = "oiii_weight"
default = 0.6                                                                # Value used if not overriden
description = "OIII contribution when synthesizing the green channel (0..1)"