#!/usr/bin/env nomsu -V4.8.10
# Some file utilities for searching for files recursively and using package.nomsupath
use "lib/os.nom"

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

%_SPOOFED_FILES = {}
%_FILE_CACHE = ({} with fallback % -> %_SPOOFED_FILES.%)
%_BROWSE_CACHE = {}

# Create a fake file and put it in the cache
externally (spoof file %filename %contents) means:
    %_SPOOFED_FILES.%filename = %contents
    return %contents

# Read a file's contents
externally (read file %filename) means:
    %contents = %_FILE_CACHE.%filename
    if %contents: return %contents
    if (%filename == "stdin"):
        return (spoof file "stdin" (=lua "io.read('*a')"))
    %file = (=lua "io.open(\%filename)")
    unless %file: return (nil)
    %contents = (call %file.read with [%file, "*a"])
    %file::close
    %_FILE_CACHE.%filename = %contents
    return %contents

externally (%path sanitized) means:
    %path = (%path::with "\\" -> "\\\\")
    %path = (%path::with "`" -> "")
    %path = (%path::with "\"" -> "\\\"")
    %path = (%path::with "$" -> "")
    %path = (%path::with "%.%." -> "\\..")
    return %path

try:
    %lfs = (=lua "require('lfs')")
..and if it succeeds:
    (filesystem has %filename) means:
        %mode = (call %lfs.attributes with [%filename, "mode"])
        if %mode is:
            "file" "directory" "link" "char device": return (yes)
            else: return (no)
    
    externally (file %path exists) means:
        if (any of [%_SPOOFED_FILES.%path, %path == "stdin", filesystem has %path]):
            return (yes)
        for %nomsupath in (%package.nomsupath::all matches of "[^;]+"):
            if (filesystem has "\(%nomsupath)/\%path"): return (yes)
        return (no)
    
    externally (files in %path) means:
        unless %_BROWSE_CACHE.%path:
            if (%_SPOOFED_FILES.%path or (%filename == "stdin")):
                %_BROWSE_CACHE.%path = [%path]
            ..else:
                if (call %lfs.attributes with [%filename, "mode"]) is:
                    "file" "char device":
                        %_BROWSE_CACHE.%path = [%filename]
                    "directory" "link":
                        for %nomsupath in (%package.nomsupath::all matches of "[^;]+"):
                            %files = []
                            for %member in (call %lfs.dir with ["\(%nomsupath)/\%filename"]):
                                if ((%member == ".") or (%member == "..")): do next %member
                                for % in (files in %member): %files::add %
                            
                            if ((size of %files) > 0):
                                %_BROWSE_CACHE.%path = %files
                                go to (Found Files)
                        
                        %_BROWSE_CACHE.%path = []
                    
                    else:
                        %_BROWSE_CACHE.%path = []
        
        === (Found Files) ===
        return %_BROWSE_CACHE.%filename
..or if it barfs:
    # LFS not found! Fall back to shell commands, if available.
    unless (sh> "find . -maxdepth 0"):
        barf "\
            ..Could not find 'luafilesystem' module and couldn't run system command 'find' (this might happen on Windows). Please install \
            ..'luafilesystem' (which can be found at \(..)
                "https://github.com/spacewander/luafilesystem" if %jit else "\
                    ..https://github.com/keplerproject/luafilesystem"
            .. or obtained through `luarocks install luafilesystem`)"
    
    externally (file %path exists) means:
        if (any of [%_SPOOFED_FILES.%path, %path == "stdin", sh> "ls \(%path sanitized)"]) \
        ..: return (yes)
        for %nomsupath in (%package.nomsupath::all matches of "[^;]+"):
            if (sh> "ls \(%nomsupath)/\%path"): return (yes)
        return (no)
    
    externally (files in %path) means:
        unless %_BROWSE_CACHE.%path:
            if %_SPOOFED_FILES.%path:
                %_BROWSE_CACHE.%path = [%_SPOOFED_FILES.%path]
            ..else:
                for %nomsupath in (%package.nomsupath::all matches of "[^;]+"):
                    %files = (sh> "find -L '\(%path)' -not -path '*/\\.*' -type f'")
                    if %files:
                        %_BROWSE_CACHE.%path = (%files::lines)
                        go to (Found Files)
                
                %_BROWSE_CACHE.%path = []
        
        === (Found Files) ===
        return %_BROWSE_CACHE.%path