#!/usr/bin/env zsh
#
# -*- mode: sh; sh-indentation: 2; indent-tabs-mode: nil; sh-basic-offset: 2; -*-
#
# Copyright (c) 2016-2020 Sebastian Gniazdowski and contributors
# Copyright (c) 2021-2022 zdharma-continuum and contributors

__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=0
  __hsmw_ctx_found=( )
  __hsmw_ctx_idx=0
  __hsmw_ctx_page_start_idx=0
  __hsmw_ctx_prev_offset=0
  __hsmw_ctx_to_search=""
  __hsmw_ctx_which=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