" scripts/download_bin.vim — install `nuwiki-ls` from a release tarball,
" falling back to `cargo build --release` on failure.
"
" Invoked by Dein / vim-plug build hooks:
"   vim -e -s -c "source scripts/download_bin.vim" -c "q"
"
" That invocation runs in 'compatible' mode, where leading-backslash line
" continuations aren't recognised (they'd raise E10, and any error in silent
" Ex mode makes Vim exit non-zero — a spurious build failure). Reset
" 'cpoptions' to the Vim default for the duration so the script parses, and
" restore it at the end.
let s:cpo_save = &cpo
set cpo&vim

let s:plugin_dir = fnamemodify(resolve(expand('<sfile>:p')), ':h:h')
let s:bin_dir    = s:plugin_dir . '/bin'
let s:suffix     = has('win32') ? '.exe' : ''
let s:bin        = s:bin_dir . '/nuwiki-ls' . s:suffix

call mkdir(s:bin_dir, 'p')

function! s:target() abort
  if has('win32')
    return 'x86_64-pc-windows-msvc'
  elseif has('mac')
    if has('arm64')
      return 'aarch64-apple-darwin'
    endif
    return 'x86_64-apple-darwin'
  elseif has('linux')
    let l:ldd = system('ldd --version 2>&1')
    let l:musl = stridx(l:ldd, 'musl') >= 0
    let l:uname_m = trim(system('uname -m'))
    if l:uname_m ==# 'aarch64' || l:uname_m ==# 'arm64'
      return l:musl ? 'aarch64-unknown-linux-musl' : 'aarch64-unknown-linux-gnu'
    endif
    return l:musl ? 'x86_64-unknown-linux-musl' : 'x86_64-unknown-linux-gnu'
  endif
  return ''
endfunction

function! s:build_from_source() abort
  if !executable('cargo')
    echohl ErrorMsg | echom 'nuwiki: cargo not found, cannot build from source' | echohl None
    return 0
  endif
  echom 'nuwiki: cargo build --release …'
  call system('cargo build --release -p nuwiki-ls --manifest-path ' . shellescape(s:plugin_dir . '/Cargo.toml'))
  if v:shell_error != 0
    echohl ErrorMsg | echom 'nuwiki: cargo build failed' | echohl None
    return 0
  endif
  let l:built = s:plugin_dir . '/target/release/nuwiki-ls' . s:suffix
  call system('cp ' . shellescape(l:built) . ' ' . shellescape(s:bin))
  call system('chmod +x ' . shellescape(s:bin))
  return executable(s:bin)
endfunction

function! s:download_release() abort
  let l:target = s:target()
  if empty(l:target)
    return 0
  endif
  if !executable('curl') || !executable('tar')
    return 0
  endif
  " Gitea serves the most recent release under the `latest` tag segment
  " (/releases/download/latest/<asset>). NOT GitHub's
  " /releases/latest/download/<asset> shape, which Gitea 404s.
  let l:url = 'https://code.gfran.co/gffranco/nuwiki/releases/download/latest/nuwiki-ls-'
        \ . l:target . '.tar.gz'
  let l:archive = tempname() . '.tar.gz'
  call system('curl -fsSL -o ' . shellescape(l:archive) . ' ' . shellescape(l:url))
  if v:shell_error != 0
    return 0
  endif
  let l:extract = tempname()
  call mkdir(l:extract, 'p')
  call system('tar -xzf ' . shellescape(l:archive) . ' -C ' . shellescape(l:extract))
  if v:shell_error != 0
    return 0
  endif
  call system('cp ' . shellescape(l:extract . '/nuwiki-ls' . s:suffix) . ' ' . shellescape(s:bin))
  call system('chmod +x ' . shellescape(s:bin))
  return executable(s:bin)
endfunction

if get(g:, 'nuwiki_build_from_source', 0)
  if !s:build_from_source()
    echohl ErrorMsg | echom 'nuwiki: source build failed' | echohl None
  endif
elseif s:download_release()
  echom 'nuwiki: installed ' . s:bin
else
  echohl WarningMsg | echom 'nuwiki: download failed, falling back to source build' | echohl None
  if !s:build_from_source()
    echohl ErrorMsg | echom 'nuwiki: install failed' | echohl None
  endif
endif

let &cpo = s:cpo_save