declare-option -docstring "options to pass to the `clang` shell command" \
    str clang_options

declare-option -hidden str clang_tmp_dir
declare-option -hidden completions clang_completions
declare-option -hidden line-specs clang_flags
declare-option -hidden line-specs clang_errors

define-command -params ..1 \
    -docstring %{Parse the contents of the current buffer
The syntaxic errors detected during parsing are shown when auto-diagnostics are enabled} \
    clang-parse %{
    evaluate-commands %sh{
        dir=$(mktemp -d "${TMPDIR:-/tmp}"/kak-clang.XXXXXXXX)
        mkfifo ${dir}/fifo
        printf %s\\n "set-option buffer clang_tmp_dir ${dir}"
        printf %s\\n "evaluate-commands -no-hooks write -sync ${dir}/buf"
    }
    # end the previous %sh{} so that its output gets interpreted by kakoune
    # before launching the following as a background task.
    evaluate-commands %sh{
        dir=${kak_opt_clang_tmp_dir}
        printf %s\\n "evaluate-commands -draft %{
                  edit! -fifo ${dir}/fifo -debug *clang-output*
                  set-option buffer filetype make
                  set-option buffer make_current_error_line 0
                  hook -always -group fifo buffer BufCloseFifo .* %{
                      nop %sh{ rm -r ${dir} }
                      remove-hooks buffer fifo
                  }
              }"
        # this runs in a detached shell, asynchronously, so that kakoune does
        # not hang while clang is running. As completions references a cursor
        # position and a buffer timestamp, only valid completions should be
        # displayed.
        (
            case ${kak_opt_filetype} in
                c) ft=c ;;
                cpp) ft=c++ ;;
                obj-c) ft=objective-c ;;
                *) ft=c++ ;;
            esac

            if [ "$1" = "-complete" ]; then
                pos=-:${kak_cursor_line}:${kak_cursor_column}
                header="${kak_cursor_line}.${kak_cursor_column}@${kak_timestamp}"
                compl=$(clang++ -x ${ft} -fsyntax-only ${kak_opt_clang_options} \
                    -Xclang -code-completion-brief-comments -Xclang -code-completion-at=${pos} - < ${dir}/buf 2> ${dir}/stderr |
                        awk -F ': ' '
                            /^COMPLETION:/ && ! /\(Hidden\)/ {
                                 id=$2
                                 gsub(/ +$/, "", id)
                                 gsub(/:/, "\\:", id)
                                 gsub(/\|/, "\\|", id)

                                 gsub(/[[{<]#|#[}>]/, "", $3)
                                 gsub(/#]/, " ", $3)
                                 gsub(/:: /, "::", $3)
                                 gsub(/ +$/, "", $3)
                                 desc=$4 ? $3 "\\n" $4 : $3

                                 gsub(/:/, "\\:", desc)
                                 gsub(/\|/, "\\|", desc)
                                 if (id in docstrings)
                                     docstrings[id]=docstrings[id] "\\n" desc
                                 else
                                     docstrings[id]=desc
                            }
                            END {
                                for (id in docstrings) {
                                    menu=id
                                    gsub(/(^|[^[:alnum:]_])(operator|new|delete)($|[^{}_[:alnum:]]+)/, "{keyword}&{}", menu)
                                    gsub(/(^|[[:space:]])(int|size_t|bool|char|unsigned|signed|long)($|[[:space:]])/, "{type}&{}", menu)
                                    gsub(/[^{}_[:alnum:]]+/, "{operator}&{}", menu)
                                    print id  "|" docstrings[id] "|" menu
                                }
                            }' | paste -s -d ':' - | sed -e "s/\\\\n/\\n/g; s/'/\\\\'/g")
                printf %s\\n "evaluate-commands -client ${kak_client} echo 'clang completion done'
                      set-option 'buffer=${kak_buffile}' clang_completions '${header}:${compl}'" | kak -p ${kak_session}
            else
                clang++ -x ${ft} -fsyntax-only ${kak_opt_clang_options} - < ${dir}/buf 2> ${dir}/stderr
                printf %s\\n "evaluate-commands -client ${kak_client} echo 'clang parsing done'" | kak -p ${kak_session}
            fi

            flags=$(cat ${dir}/stderr | sed -rne "
                        /^<stdin>:[0-9]+:([0-9]+:)? (fatal )?error/ { s/^<stdin>:([0-9]+):.*/\1|{red}█/; p }
                        /^<stdin>:[0-9]+:([0-9]+:)? warning/ { s/^<stdin>:([0-9]+):.*/\1|{yellow}█/; p }
                    " | paste -s -d ':' -)

            errors=$(cat ${dir}/stderr | sed -rne "
                        /^<stdin>:[0-9]+:([0-9]+:)? ((fatal )?error|warning)/ {
                            s/^<stdin>:([0-9]+):([0-9]+:)? (.*)/\1|\3/
                            s/'/\\\\'/g; s/:/\\\\:/g; p
                        }" | sort -n | paste -s -d ':' -)

            sed -e "s|<stdin>|${kak_bufname}|g" < ${dir}/stderr > ${dir}/fifo

            printf %s\\n "set-option 'buffer=${kak_buffile}' clang_flags %{${kak_timestamp}:${flags}}
                  set-option 'buffer=${kak_buffile}' clang_errors '${kak_timestamp}:${errors}'" | kak -p ${kak_session}
        ) > /dev/null 2>&1 < /dev/null &
    }
}

define-command clang-complete -docstring "Complete the current selection" %{ clang-parse -complete }

define-command -hidden clang-show-completion-info %[ try %[
    evaluate-commands -draft %[
        execute-keys <space>{( <a-k> ^\( <ret> b <a-k> \A\w+\z <ret>
        evaluate-commands %sh[
            desc=$(printf %s\\n "${kak_opt_clang_completions}" | sed -e "{ s/\([^\\]\):/\1\n/g }" | sed -ne "/^${kak_selection}|/ { s/^[^|]\+|//; s/|.*$//; s/\\\:/:/g; p }")
            if [ -n "$desc" ]; then
                printf %s\\n "evaluate-commands -client $kak_client %{info -anchor ${kak_cursor_line}.${kak_cursor_column} -placement above %{${desc}}}"
            fi
    ] ]
] ]

define-command clang-enable-autocomplete -docstring "Enable automatic clang completion" %{
    set-option window completers "option=clang_completions:%opt{completers}"
    hook window -group clang-autocomplete InsertIdle .* %{
        try %{
            execute-keys -draft <a-h><a-k>(\.|->|::).\z<ret>
            echo 'completing...'
            clang-complete
        }
        clang-show-completion-info
    }
    alias window complete clang-complete
}

define-command clang-disable-autocomplete -docstring "Disable automatic clang completion" %{
    set-option window completers %sh{ printf %s\\n "'${kak_opt_completers}'" | sed -e 's/option=clang_completions://g' }
    remove-hooks window clang-autocomplete
    unalias window complete clang-complete
}

define-command -hidden clang-show-error-info %{
    update-option buffer clang_errors # Ensure we are up to date with buffer changes
    evaluate-commands %sh{
        desc=$(printf %s\\n "${kak_opt_clang_errors}" |
               sed -e "s/\([^\\]\):/\1\n/g" |
               sed -ne "/^${kak_cursor_line}|.*/ { s/^[[:digit:]]\+|//g; s/'/\\\\'/g; s/\\\\:/:/g; p }")
        if [ -n "$desc" ]; then
            printf %s\\n "info -anchor ${kak_cursor_line}.${kak_cursor_column} '${desc}'"
        fi
    } }

define-command clang-enable-diagnostics -docstring %{Activate automatic error reporting and diagnostics
Information about the analysis are showned after the buffer has been parsed with the clang-parse function} \
%{
    add-highlighter window flag_lines default clang_flags
    hook window -group clang-diagnostics NormalIdle .* %{ clang-show-error-info }
    hook window -group clang-diagnostics WinSetOption ^clang_errors=.* %{ info; clang-show-error-info }
}

define-command clang-disable-diagnostics -docstring "Disable automatic error reporting and diagnostics" %{
    remove-highlighter window/hlflags_clang_flags
    remove-hooks window clang-diagnostics
}

define-command clang-diagnostics-next -docstring "Jump to the next line that contains an error" %{
    update-option buffer clang_errors # Ensure we are up to date with buffer changes
    evaluate-commands %sh{
        printf "%s\n" "${kak_opt_clang_errors}" | sed -e 's/\([^\\]\):/\1\n/g' | tail -n +2 | (
            while IFS='|' read candidate rest; do
                first_line=${first_line-$candidate}
                if [ "$candidate" -gt $kak_cursor_line ]; then
                    line=$candidate
                    break
                fi
            done
            line=${line-$first_line}
            if [ -n "$line" ]; then
                printf %s\\n "execute-keys ${line} g"
            else
                echo "echo -markup '{Error}no next clang diagnostic'"
            fi
        )
    } }