[repo]
kind = "recipe"

[recipe]
description = "Blend a controllable fraction of the removed stars back into the VeraLux-stretched starless image."

[[stages]]
name = "merge_stars"
description = "Screen-blend the removed stars back into the stretched starless image"
tool.name = "siril"

# Base = hms_starless_<palette>.fits (VeraLux, already stretched).
# Star layer = its sibling starmask_<palette>.fits (starnet, linear/unstretched),
# autostretched into the same tonal range, scaled by merge_star_amount, then
# screen-blended back over the starless image.
script = '''
    load "{input[0].full_paths[0]}"
    save starless

    load "{str(input[0].full_paths[0].parent / (input[0].full_paths[0].stem.replace('hms_starless_', 'starmask_') + '.fits'))}"
    asinh -human {parameters.stretch}
    save stars

    pm "1 - (1 - $starless$) * (1 - $stars$)"
    save results

    load results
    save "{output.full_paths[0]}"
    '''

[[stages.inputs]]
kind = "job"
after = "veralux.*"
multiplex = true # one task per upstream file, so multi-file stacks (e.g. SHO/HOO) each get merged

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

# Belt-and-suspenders: only operate on starless files (VeraLux already skips starmask).
[[stages.inputs.requires]]
kind = "filename"
value = "hms_starless"
mode = "include"

[[stages.outputs]]
kind = "processed"
# merged_<palette>.fits, derived from hms_starless_<palette>.fits
name = ["{input[0].full_paths[0].stem.replace('hms_starless_', 'merged_')}.fits"]

[[stages.parameters]]
name = "stretch"
default = 1000.0
description = "asinh stretch factor applied to the linear starmask before blending (higher = more stars visible)"