#!/bin/sh

set -eu

. "$HOME/.config/fzf-vcal/config"

__load_weeks() {
  # TODO: Make sensitive to failures. I don't want to miss appointments!
  file_weeks=$(mktemp)
  find "$ROOT" -type f -name '*.ics' -print0 |
    xargs -0 -P0 \
      awk -f "src/weeks.awk" >"$file_weeks"
  dates=$(awk -F'|' '{ print $1; print $2 }' "$file_weeks")
  file_dates=$(mktemp)
  echo "$dates" | date --file="/dev/stdin" +"%s" >"$file_dates"
  awk -f "src/merge.awk" "$file_dates" "$file_weeks"
  rm "$file_weeks" "$file_dates"
}

if [ -z "${WEEKLY_DATA:-}" ]; then
  WEEKLY_DATA=$(__load_weeks)
  export WEEKLY_DATA
fi

__list() {
  weeknr=$(date -d "$DISPLAY_DATE" +"%s")
  weeknr=$(((weeknr - 259200) / 604800)) # shift, because epoch origin is a Thursday
  files=$(echo "$WEEKLY_DATA" | grep "^$weeknr " | cut -d " " -f 2)
  dayofweek=$(date -d "$DISPLAY_DATE" +"%u")
  delta=$((1 - dayofweek))
  startofweek=$(date -d "$DISPLAY_DATE -$delta days" +"%D")
  # loop over files
  sef=$({
    IFS=';'
    set -- $files
    for file in "$@"; do
      file="$ROOT/$file"
      awk -f "src/parse.awk" "$file"
    done
  })
  if [ -n "$sef" ]; then
    sef=$(echo "$sef" | while IFS= read -r line; do
      set -- $line
      starttime="$1"
      shift
      endtime="$1"
      shift
      description="$*"
      for i in $(seq 0 7); do
        daystart=$(date -d "$startofweek +$i days 00:00:00" +"%s")
        dayend=$(date -d "$startofweek +$i days 23:59:59" +"%s")
        if [ "$starttime" -gt "$daystart" ] && [ "$starttime" -lt "$dayend" ]; then
          s=$(date -d "@$starttime" +"%H:%M")
          s="$s -"
        elif [ "$starttime" -le "$daystart" ] && [ "$endtime" -gt "$daystart" ]; then
          s="00:00 -"
        else
          continue
        fi
        if [ "$endtime" -gt "$daystart" ] && [ "$endtime" -lt "$dayend" ]; then
          e=$(date -d "@$endtime" +"%H:%M")
          e="- $e"
        elif [ "$endtime" -ge "$dayend" ] && [ "$starttime" -lt "$dayend" ]; then
          e="- 00:00"
        else
          continue
        fi
        echo "$i $s$e >$description"
      done
    done)
  fi
  sef=$({
    echo "$sef"
    seq 0 7
  } | sort -n)
  echo "$sef" | awk -v startofweek="$startofweek" -f "src/weekview.awk"
  #seq -f "$startofweek +%g days" 0 6 |
  #  LC_ALL=c xargs -I {} date -d "{}" +"%a %e %b %Y"
}

DISPLAY_DATE="today"
if [ "${1:-}" = "--date" ]; then
  DISPLAY_DATE="$2"
  echo "Jumping to date $2!"
fi
DISPLAY_DATE=$(date -d "$DISPLAY_DATE" +"%D")
DISPLAY_DATE_PREV=$(date -d "$DISPLAY_DATE -1 week" +"%D")
DISPLAY_DATE_NEXT=$(date -d "$DISPLAY_DATE +1 week" +"%D")

__list |
  fzf \
    --tac \
    --no-sort \
    --ansi \
    --bind="ctrl-p:become($0 --date '$DISPLAY_DATE_PREV')" \
    --bind="ctrl-n:become($0 --date '$DISPLAY_DATE_NEXT')"