" Stolen from https://vimways.org/2018/colder-quickfix-lists/
" ~/.vim/autoload/quickfixed.vim
function! s:isLocation()
    " Get dictionary of properties of the current window
    let wininfo = filter(getwininfo(), {i,v -> v.winnr == winnr()})[0]
    return wininfo.loclist
endfunction

function! s:length()
    " Get the size of the current quickfix/location list
    return len(s:isLocation() ? getloclist(0) : getqflist())
endfunction

function! s:getProperty(key, ...)
    " getqflist() and getloclist() expect a dictionary argument
    " If a 2nd argument has been passed in, use it as the value, else 0
    let l:what = {a:key : a:0 ? a:1 : 0}
    let l:listdict = s:isLocation() ? getloclist(0, l:what) : getqflist(l:what)
    return get(l:listdict, a:key)
endfunction

function! s:isFirst()
    return s:getProperty('nr') <= 1
endfunction

function! s:isLast()
    return s:getProperty('nr') == s:getProperty('nr', '$')
endfunction

function! s:history(goNewer)
    " Build the command: one of colder/cnewer/lolder/lnewer
    let l:cmd = (s:isLocation() ? 'l' : 'c') . (a:goNewer ? 'newer' : 'older')

    " Apply the cmd repeatedly until we hit a non-empty list, or first/last list
    " is reached
    while 1
        if (a:goNewer && s:isLast()) || (!a:goNewer && s:isFirst()) | break | endif
        " Run the command. Use :silent to suppress message-history output.
        " Note that the :try wrapper is no longer necessary
        silent execute l:cmd
        if s:length() | break | endif
    endwhile

    " Set the height of the quickfix window to the size of the list, max-height 10
    execute 'resize' min([ 10, max([ 1, s:length() ]) ])

    " Echo a description of the new quickfix / location list.
    " And make it look like a rainbow.
    let l:nr = s:getProperty('nr')
    let l:last = s:getProperty('nr', '$')
    echohl MoreMsg | echon '('
    echohl Identifier | echon l:nr
    if l:last > 1
        echohl LineNr | echon ' of '
        echohl Identifier | echon l:last
    endif
    echohl MoreMsg | echon ') '
    echohl MoreMsg | echon '['
    echohl Identifier | echon s:length()
    echohl MoreMsg | echon '] '
    echohl Normal | echon s:getProperty('title')
    echohl None
endfunction

function! quickfixed#older()
    call s:history(0)
endfunction

function! quickfixed#newer()
    call s:history(1)
endfunction