#!/usr/bin/env bash

# Description: Run custom search and list results in smart context
#
# Note: This plugin retains search history
#
# Usage:
#   Run plugin and enter e.g. "-size +10M" to list files in current
#   directory larger than 10M. By default entered expressions are
#   interpreted as arguments to find. Results have to be NUL
#   terminated which is done by default for find. Alternatively one
#   can prepend a '$' to run a custom search program such as fd or
#   ripgrep. Entered expressions will be saved in history file to
#   be listed as bookmarks and and can be entered by index and edited.
#
# Shell: Bash
# Author: Arun Prakash Jana, Luuk van Baal
TMPDIR="${TMPDIR:-/tmp}"
NNN_FINDHIST="${NNN_FINDHIST:-${XDG_CONFIG_HOME:-$HOME/.config}/nnn/finderbms}"
NNN_FINDHISTLEN="${NNN_FINDHISTLEN:-10000}"

printexamples() {
    printf -- "-maxdepth 1 -name pattern
-maxdepth 1 -size +100M
\$fd -0 pattern
\$fd -0 -d 2 -S +100M
\$grep -rlZ pattern
\$rg -l0 pattern
\$fzf -m | tr '\\\n' '\\\0'\n"
}

printexprs() {
    for ((i = "$1"; i < ${#fexprs[@]}; i++)); do
        printf '%s\t%s\n' "$((i + 1))" "${fexprs[$i]}"
    done
}

mapexpr() {
    if [ "$fexpr" -eq "$fexpr" ] 2>/dev/null; then
        fexpr=${fexprs[$((fexpr - 1))]}
        read -r -e -p "Search expression: " -i "$fexpr" fexpr
    else
        return 1
    fi
}

readexpr() {
    case "$fexpr" in
        h)   clear
             printf "Examples:\n"
             mapfile -t fexprs < <(printexamples)
             printexprs 0
             read -r -p "Search expression or index: " fexpr
             mapexpr
             [ -n "$fexpr" ] && readexpr ;;
        \$*) cmd="${fexpr:1}" ;;
        *)   mapexpr && readexpr
             cmd="find . $fexpr -print0" ;;
    esac
}

clear
[ -f "$NNN_FINDHIST" ] || printexamples > "$NNN_FINDHIST"

mapfile -t fexprs < <(sort "$NNN_FINDHIST" | uniq -c | sort -nr | head -n5 |\
  awk '{for (i=2; i<NF; i++) printf $i " "; print $NF}')
printf "Most used search expressions:\n"
printexprs 0

mapfile -t -O"$i" fexprs < <(tac "$NNN_FINDHIST" | awk '!a[$0]++' | head -n5)
printf "Most recently used search expressions:\n"
printexprs "$i"
read -r -p "Search expression or index (h for help): " fexpr

mapexpr

if [ -n "$fexpr" ]; then
    printf "+l" > "$NNN_PIPE"
    while :; do
        readexpr
        eval "$cmd" > "$NNN_PIPE" && break
        read -r -e -p "Search expression: " -i "$fexpr" fexpr
    done
    if [ -n "$fexpr" ]; then
        tail -n"$NNN_FINDHISTLEN" "$NNN_FINDHIST" > "$TMPDIR/finderbms"
        printf "%s\n" "$fexpr" >> "$TMPDIR/finderbms"
        mv "$TMPDIR/finderbms" "$NNN_FINDHIST"
    fi
fi
