#!/usr/bin/env bash

set -euo pipefail

EDITOR="${EDITOR:-nvim}"
ZET_DIR="${ZET_DIR:-$HOME/Documents/zet}"
ZET_TMP_FILE="$HOME/.local/state/zets"

if [[ ! -d "$ZET_DIR" ]]; then
  mkdir -p "$ZET_DIR"
  (cd "$ZET_DIR" && git init)
  git -C "$ZET_DIR" add .
  git -C "$ZET_DIR" commit -m 'Initial commit'
fi

commit_changes() {
  filename="$1"
  commit_message="$2"

  git -C "$ZET_DIR" diff --quiet "$filename" || {
    read -rp "Commit? " commit_choice

    if [[ "$commit_choice" =~ ^[Yy]$ ]]; then
      git -C "$ZET_DIR" add "$filename"

      commit_message="${commit_message//$ZET_DIR\//}"
      commit_message="${commit_message//\/index.adoc/}"

      git -C "$ZET_DIR" commit -m "$commit_message"

      echo "Changes committed."
    else
      echo "Changes not committed."
    fi
  }
}

delete_zet() {
  query="$1"

  if [[ "$1" == "last" ]]; then
    file="$(find "$ZET_DIR" -type f -name "index.adoc" | sort | tail -1)"
  else
    file="$(get_filepath_for_zet "$query")"
  fi

  if [[ -f "$file" ]]; then
    run_git_command rm -rf "$file"

    commit_message="Delete $file"
    commit_message="${commit_message//$ZET_DIR\//}"
    commit_message="${commit_message//\/index.adoc/}"

    git -C "$ZET_DIR" commit -m "$commit_message"

    update_zet_list
  else
    result="$(search_zets "$query")"
    result_count="$(echo "$result" | grep -c '^')"

    if [[ "$result_count" -eq 0 ]]; then
      echo "No results found for query: $query" >&2
      exit 1
    elif [[ "$result_count" -eq 1 ]]; then
      id="$(echo "$result" | awk '{print $1}')"
    else
      selected="$(echo "$result" | sort | fzf)" || exit 0

      id="$(echo "$selected" | awk '{print $1}')"
    fi

    delete_zet "$id"
  fi

}

edit_zet() {
  query="$1"

  if [[ "$1" == "last" ]]; then
    file="$(get_last_zet)"
  else
    file="$(get_filepath_for_zet "$query")"
  fi

  if [[ -f "$file" ]]; then
    "$EDITOR" "$file"

    commit_changes "$file" "Edit $file"

    update_zet_list
  else
    result="$(search_zets "$query")"
    result_count="$(echo "$result" | grep -c '^')"

    if [[ "$result_count" -eq 0 ]]; then
      echo "No results found for query: $query" >&2
      exit 1
    elif [[ "$result_count" -eq 1 ]]; then
      id="$(echo "$result" | awk '{print $1}')"
    else
      selected="$(echo "$result" | sort | fzf)" || exit 0

      id="$(echo "$selected" | awk '{print $1}')"
    fi

    edit_zet "$id"
  fi
}

generate_links() {
  query="$1"

  related="$(search_zets "$query")"

  echo "$related" | while IFS= read -r line; do
    id="${line%% *}"
    title="${line#* }"
    echo "* link:../${id}/index.adoc[${title}]"
  done | sort
}

get_filepath_for_zet() {
  echo "${ZET_DIR}/$1/index.adoc"
}

get_last_zet() {
  find "$ZET_DIR" -type f -name "index.adoc" | sort | tail -1
}

get_zet_id_from_filepath() {
  basename "$(dirname "$file")"
}

main() {
  [[ $# -eq 0 ]] && show_titles && exit

  case "${1:-}" in
    delete) delete_zet "$2" ;;
    edit) edit_zet "$2" ;;
    find|search) shift 1; search_zets "$@" ;;
    git) shift 1; run_git_command "$@" ;;
    links) generate_links "$2" ;;
    new|create) shift 1; new_zet "$@" ;;
    source) show_zet "$2" ;;
    titles) show_titles ;;
    *) search_zets "$1";
  esac
}

new_zet() {
  id="$(date "+%Y%m%d%H%M%S")"
  filename="$(get_filepath_for_zet "$id")"
  mkdir -p "$(dirname "$filename")"

  title="$*"
  echo "= $title" > "$filename"
  echo "$id $title" >> "$ZET_TMP_FILE"

  "$EDITOR" "$filename"

  run_git_command add --intent-to-add "$filename"
  commit_changes "$filename" "Add $filename"
}

run_git_command() {
  git -C "$ZET_DIR" "$@"
}

search_zets() {
  grep --recursive --ignore-case --files-with-matches --exclude-dir=.git "$*" "$ZET_DIR" | while read -r file; do
    id="$(get_zet_id_from_filepath "$file")"
    title=$(head -1 "$file" | sed 's/^= //' | sed 's/# //')

    echo "$id $title"
  done | sort
}

show_titles() {
  cat "$ZET_TMP_FILE"
}

show_zet() {
  id="$1"
  file="$(get_filepath_for_zet "$id")"

  if [[ -f "$file" ]]; then
    cat "$file" && exit 0
  fi

  echo "Note not found: $id" >&2
  exit 1
}

update_zet_list() {
  find "$ZET_DIR" -type f -name 'index.adoc' | while read -r file; do
    id="$(get_zet_id_from_filepath "$file")"
    title=$(head -n 1 "$file" | sed 's/^= //' | sed 's/^# //')

    echo "$id $title"
  done | sort > "$ZET_TMP_FILE" &
}

main "$@"