#!/bin/bash

hr_msg() {
    printf -- '\n--- %s ---\n\n' "$1" >&2
}

debug() {
    if (( DEBUG )); then
        printf '%s\n' "$@" >&2
    fi
}

print_debug_info() {
    # DEBUG comes from the environment
    if ! (( DEBUG )); then
        return
    fi

    local msg="${1?}"

    hr_msg "$msg"

    hr_msg Environment
    env | LC_ALL=C sort >&2

    cgroup_path=/proc/$$/cgroup

    if [[ -f $cgroup_path ]]; then
        hr_msg cgroup
        cat "$cgroup_path" >&2
    else
        hr_msg 'NO CGROUP'
    fi

    hr_msg 'Finished debug info'
}

print_debug_info 'Initialising'

cache_dir=$HOME/.clipmenu/

# It's ok that this only applies to the final directory.
# shellcheck disable=SC2174
mkdir -p -m0700 "$cache_dir"

declare -A last_data
declare -A last_filename

while sleep "${CLIPMENUD_SLEEP:-0.5}"; do
    print_debug_info 'About to run selection'

    for selection in clipboard primary; do
        print_debug_info "About to do selection for '$selection'"

        if type -p xsel >/dev/null 2>&1; then
            debug 'Using xsel'
            data=$(xsel --logfile /dev/null -o --"$selection"; printf x)
        else
            debug 'Using xclip'
            data=$(xclip -o -sel "$selection"; printf x)
        fi

        debug "Data before stripping: $data"

        # We add and remove the x so that trailing newlines are not stripped.
        # Otherwise, they would be stripped by the very nature of how POSIX
        # defines command substitution.
        data=${data%x}

        debug "Data after stripping: $data"

        if [[ $data != *[^[:space:]]* ]]; then
            debug "Skipping as clipboard is only blank"
            continue
        fi

        if [[ ${last_data[$selection]} == "$data" ]]; then
            debug 'Skipping as last selection is the same as this one'
            continue
        fi

        # If we were in the middle of doing a selection when the previous poll
        # ran, then we may have got a partial clip.
        possible_partial=${last_data[$selection]}
        if [[ $possible_partial && $data == "$possible_partial"* ]]; then
            debug "$possible_partial is a possible partial of $data"
            debug "Removing ${last_filename[$selection]}"
            rm -- "${last_filename[$selection]}"
        fi

        filename="$cache_dir/$(LC_ALL=C date +%F-%T.%N)"

        last_data[$selection]=$data
        last_filename[$selection]=$filename

        debug "Writing $data to $filename"
        printf '%s' "$data" > "$filename"

        if ! (( NO_OWN_CLIPBOARD )) && [[ $selection != primary ]]; then
            # Take ownership of the clipboard, in case the original application
            # is unable to serve the clipboard request (due to being suspended,
            # etc).
            #
            # Primary is excluded from the change of ownership as applications
            # sometimes act up if clipboard focus is taken away from them --
            # for example, urxvt will unhilight text, which is undesirable.
            #
            # We can't colocate this with the above copying code because
            # https://github.com/cdown/clipmenu/issues/34 requires knowing if
            # we would skip first.
            if type -p xsel >/dev/null 2>&1; then
                xsel --logfile /dev/null -o --"$selection" | xsel -i --"$selection"
            else
                xclip -o -sel "$selection" | xclip -i -sel "$selection"
            fi
        fi

        if ! (( NO_TRANSFER_CLIPBOARD )) && [[ $selection != primary ]]; then
            # Copy every clipboard content into primary clipboard
            if type -p xsel >/dev/null 2>&1; then
                xsel --logfile /dev/null -o --"$selection" | xsel -i --primary
            else
                xclip -o -sel "$selection" | xclip -i -sel primary
            fi
        fi
    done
done