# -*- Mode: sh; sh-indentation: 4; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
# vim:ft=zsh:sw=4:sts=4:et

__hsmw_ctx_prev_idx="$__hsmw_ctx_idx"

[[ "$WIDGET" = *-word ]] && (( __hsmw_ctx_idx -- ))
[[ "$WIDGET" = *-backwards ]] && (( __hsmw_ctx_idx ++ ))
[[ "$WIDGET" = *-pforwards ]] && (( __hsmw_ctx_idx = __hsmw_ctx_idx - __hsmw_page_size ))
[[ "$WIDGET" = *-pbackwards ]] && (( __hsmw_ctx_idx = __hsmw_ctx_idx + __hsmw_page_size ))

_hsmw_ctx_up() {
    (( __hsmw_ctx_which -- ))
    (( __hsmw_ctx_which < 0 )) && __hsmw_ctx_which=${#__hsmw_ctx_found}-1
    __hsmw_ctx_idx=0
    _hsmw_ctx_main
}

_hsmw_ctx_down() {
    (( __hsmw_ctx_which ++ ))
    (( __hsmw_ctx_which >= ${#__hsmw_ctx_found} )) && __hsmw_ctx_which=0
    __hsmw_ctx_idx=0
    _hsmw_ctx_main
}

_hsmw_ctx_off() {
    __hsmw_ctx_to_search=""
    __hsmw_ctx_found=( )
    __hsmw_ctx_which=0
    __hsmw_ctx_idx=0
    __hsmw_ctx_page_start_idx=0
    __hsmw_ctx_prev_offset=0
    __hsmw_ctx=0

    # Reset main state so that it re-highlights
    __hsmw_prev_offset=0

    zle -la _hsmw_ctx_down && zle -D _hsmw_ctx_down
    zle -la _hsmw_ctx_up && zle -D _hsmw_ctx_up

    bindkey -M hsmw '^N' "history-search-multi-word"
    bindkey -M hsmw '^P' "history-search-multi-word-backwards"

    (( ${1}+0 )) && _hsmw_simulate_widget
}

if [[ "$WIDGET" = "hsmw-context-main" ]]; then
    __hsmw_ctx=1-__hsmw_ctx
    if (( __hsmw_ctx == 0 )); then
        _hsmw_ctx_off 1
        return
    fi

    zle -N _hsmw_ctx_down
    zle -N _hsmw_ctx_up
    bindkey -M hsmw '^N' "_hsmw_ctx_down"
    bindkey -M hsmw '^P' "_hsmw_ctx_up"
fi

_hsmw_ctx_main() {

    # The repeat will make the matching work on a fresh heap arena
    local to_search="${__hsmw_hcw_found[__hsmw_hcw_index]}" nl=$'\n'
    to_search="${to_search//(#m)[][*?|#~^()><\\]/\\$MATCH}"

    if [[ "$to_search" != "$__hsmw_ctx_to_search" ]]; then
        __hsmw_ctx_to_search="$to_search"
        repeat 1; do
            __hsmw_ctx_found=( "${(@kv)history[(R)$to_search]}" )
            __hsmw_ctx_text_idx="${__hsmw_ctx_found[(I)$to_search]}"
            if [[ "$__hsmw_ctx_text_idx" = "0" ]]; then
                _hsmw_ctx_off 1
                return 0
            fi
            __hsmw_ctx_found[__hsmw_ctx_text_idx]=()
        done
    fi

    integer final_hist_found_idx
    final_hist_found_idx=__hsmw_ctx_text_idx+__hsmw_ctx_which-1

    integer the_index="${__hsmw_ctx_found[final_hist_found_idx]}"
    the_index=the_index+__hsmw_ctx_idx

    integer max_index=$(( ${${(k)history[@]}[1]} + 1 ))
    if [[ "$max_index" -le "0" ]]; then
        POSTDISPLAY=$'\n'"No matches found"
        return 0
    fi

    #
    # Pagination, index value guards
    #

    integer page_size="$__hsmw_page_size"
    [[ "$page_size" -gt "$max_index" ]] && page_size="$max_index"
    [[ "$the_index" -le 0 ]] && { __hsmw_ctx_idx="$__hsmw_ctx_prev_idx"; the_index=1; }
    [[ "$the_index" -gt "$(( max_index - 1))" ]] && { __hsmw_ctx_idx="$__hsmw_ctx_prev_idx"; the_index="$(( max_index - 1 ))"; }
    integer page_start_idx=$(( ((the_index-1)/page_size)*page_size+1 ))
    integer on_page_idx=$(( page_size - (the_index - page_start_idx) ))

    #
    # Prepare display
    #

    if [[ "$page_start_idx" != "$__hsmw_ctx_page_start_idx" ]]; then
        integer idx
        __hsmw_ctx_disp_list=( )
        for (( idx = page_start_idx + page_size - 1; idx >= page_start_idx ; idx -- )); do
            __hsmw_ctx_disp_list+=( "${history[$idx]}" )
        done

        # Don't do @ splitting, it's slower
        __hsmw_ctx_disp_list_newlines=( "${__hsmw_ctx_disp_list[@]}" )

        # Replace all new lines with "\n" text
        __hsmw_ctx_disp_list=( "${(@)__hsmw_ctx_disp_list//$'\n'/\\n}" )
        # Truncate to display width, preceede by two spaces
        __hsmw_ctx_disp_list=( "${(@)__hsmw_ctx_disp_list/(#m)*/  ${MATCH[1,COLUMNS-8]}}" )

        # The same with newlines adapted for syntax highlighting
        __hsmw_ctx_disp_list_newlines=( "${(@)__hsmw_ctx_disp_list_newlines//$'\n'/ $nl}" )
        __hsmw_ctx_disp_list_newlines=( "${(@)__hsmw_ctx_disp_list_newlines/(#m)*/  ${MATCH[1,COLUMNS-8]}}" )
    fi

    #
    # Detect where "> .." entry starts, add the ">" mark
    #

    local txt_before="${(F)${(@)__hsmw_ctx_disp_list[1,on_page_idx-1]}}"
    local entry="${__hsmw_ctx_disp_list[on_page_idx]}"
    local text="${(F)__hsmw_ctx_disp_list}"
    integer replace_idx=${#txt_before}+2
    (( replace_idx == 2 )) && replace_idx=1
    text[replace_idx]=">"

    #
    # Colorify
    #

    local preamble=$'\n'"Showing context of history entry. Ctrl-K to return to search."
    local preamble2=$'\n'"Ctrl-N/P: next/previous occurence. Occurence #$(( __hsmw_ctx_which + 1 )) of ${#__hsmw_ctx_found}"
    preamble2=${(r:${#preamble}:: :)preamble2}$'\n'
    preamble+=$preamble2

    integer offset=${#preamble}+${#BUFFER}
    POSTDISPLAY="$preamble$text"

    if (( page_start_idx != __hsmw_ctx_page_start_idx || offset != __hsmw_ctx_prev_offset )); then
        region_highlight=( "${#BUFFER} $offset bg=22" )
        if (( __hsmw_synhl )); then
            integer pre_index=$offset
            local line
            for line in "${__hsmw_ctx_disp_list_newlines[@]}"; do
                reply=( )
                -hsmw-highlight-process "$line" "$pre_index"
                region_highlight+=( $reply )
                pre_index+=${#line}+1
            done
        fi
    else
        region_highlight[-1]=()
    fi

    __hsmw_ctx_page_start_idx=page_start_idx
    __hsmw_ctx_prev_offset=offset

    region_highlight+=( "$(( offset + ${#txt_before} )) $(( offset + ${#txt_before} + ${#entry} + 1 )) $__hsmw_active" )
}

_hsmw_ctx_main