#!/bin/sh

# Set modification date of the current (or specified) directory
# to the earliest file in that directory.
#
# License: LGPLv2
#
# I use this when I don't want to record when I (re)filed something,
# and would like the directories to be ordered by date of the contents.
# Digital camera pictures is usually what I use this for.

test -z $1 && set "."
global file := $[find $1 -maxdepth 1 -type f -printf "%p\t%T@\n" | sort -k2,2n | head -1 | cut -f1]
test -z $file && exit
global filedate := $[date --reference="$file" +%y%m%d%H%M]
touch -c -t $filedate $1
(CommandList
  children: [
    (AndOr
      children: [
        (C {(Lit_Other "[")} {(-z)} {(DQ ($ VSub_Number "$1"))} {(Lit_Other "]")})
        (C {(set)} {(DQ (.))})
      ]
      op_id: Op_DAmp
    )
    (Assignment
      keyword: Assign_None
      pairs: [
        (assign_pair
          lhs: (LhsName name:file)
          op: Equal
          rhs: 
            {
              (CommandSubPart
                command_list: 
                  (CommandList
                    children: [
                      (Pipeline
                        children: [
                          (C {(find)} {($ VSub_Number "$1")} {(-maxdepth)} {(1)} {(-type)} {(f)} {(-printf)} 
                            {
                              (DQ ("%p") (EscapedLiteralPart token:<Lit_EscapedChar "\\t">) ("%T@") 
                                (EscapedLiteralPart
                                  token: <Lit_EscapedChar "\\n">
                                )
                              )
                            }
                          )
                          (C {(sort)} {(-k2) (Lit_Comma ",") (2n)})
                          (C {(head)} {(-1)})
                          (C {(cut)} {(-f1)})
                        ]
                        negated: False
                      )
                    ]
                  )
                left_token: <Left_Backtick "`">
                spids: [48 89]
              )
            }
          spids: [47]
        )
      ]
      spids: [47]
    )
    (AndOr
      children: [
        (C {(Lit_Other "[")} {(-z)} {(DQ ($ VSub_Name "$file"))} {(Lit_Other "]")})
        (C {(exit)})
      ]
      op_id: Op_DAmp
    )
    (Assignment
      keyword: Assign_None
      pairs: [
        (assign_pair
          lhs: (LhsName name:filedate)
          op: Equal
          rhs: 
            {
              (CommandSubPart
                command_list: 
                  (CommandList
                    children: [
                      (C {(date)} {(--reference) (Lit_Other "=") (DQ ($ VSub_Name "$file"))} 
                        {(Lit_Other "+") (Lit_Other "%") (y) (Lit_Other "%") (m) (Lit_Other "%") (d) 
                          (Lit_Other "%") (H) (Lit_Other "%") (M)
                        }
                      )
                    ]
                  )
                left_token: <Left_Backtick "`">
                spids: [106 126]
              )
            }
          spids: [105]
        )
      ]
      spids: [105]
    )
    (C {(touch)} {(-c)} {(-t)} {($ VSub_Name "$filedate")} {($ VSub_Number "$1")})
  ]
)