#!/usr/bin/env bash
# Dikte updater: pull, put the launchers back, restart what was running.
set -euo pipefail

# The checkout, one level up: this script lives in scripts/, everything it
# touches is at the top of the tree.
DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
ENTRY="$DIR/dikte/__main__.py"
USER_NAME="$(id -un)"

if [[ "$(uname -s)" == "Darwin" ]]; then
  # Apple's python3 is 3.9 and will stay 3.9, so the one on PATH is the wrong
  # question here. install-mac.sh names the interpreter it installed against in
  # the wrapper it wrote, and that is the one this installation runs on.
  # `|| true` because there may be no wrapper to read: pipefail would otherwise
  # make a missing file the end of the script rather than a question answered no.
  PY="$(sed -n 's/^exec "\([^"]*\)".*/\1/p' "$HOME/.local/bin/dikte" 2>/dev/null | head -1 || true)"
  [[ -x "$PY" ]] || PY="$(command -v python3 || true)"
else
  PY="$(command -v python3 || true)"
fi

say()  { printf '  %s\n' "$1"; }
ok()   { printf '  \033[32m✓\033[0m %s\n' "$1"; }
warn() { printf '  \033[33m!\033[0m %s\n' "$1"; }
die()  { printf '  \033[31m✗\033[0m %s\n' "$1"; echo; exit 1; }

echo
echo "Updating Dikte"
echo "──────────────"

cd "$DIR"

# 1. Somewhere there is something to pull ----------------------------------
command -v git >/dev/null || die "git not found; update by downloading the source again"
git rev-parse --git-dir >/dev/null 2>&1 \
  || die "$DIR is not a git checkout; update by downloading the source again"

before="$(git rev-parse HEAD)"

# 2. Is there anything to come? ---------------------------------------------
# Asked before anything else is complained about: an unfinished afternoon in
# the working tree is nobody's problem on a day when nothing has been
# published. Fetching leaves the working tree alone.
git fetch --quiet || die "Could not reach the remote."
upstream="$(git rev-parse '@{u}' 2>/dev/null)" \
  || die "This branch is not tracking a remote one; pull by hand."

if [[ "$before" == "$upstream" ]]; then
  echo
  ok "Already up to date ($(git log -1 --format=%s))"
  echo
  exit 0
fi

# 3. Only now, your own edits -----------------------------------------------
# They would be overwritten by a fast-forward or would block it, and either way
# that is your call to make, not this script's. Untracked files are counted
# too: a fast-forward that adds a file of that name stops on them.
if [[ -n "$(git status --porcelain)" ]]; then
  warn "There is an update waiting, but you have changes of your own here:"
  git --no-pager status --short | sed 's/^/    /'
  say "Commit them, or put them aside with:  git stash --include-untracked"
  die "Nothing was updated."
fi

# --ff-only: an update should be somebody else's commits arriving, never a
# merge this script decided to make on your behalf. The fetch above already
# brought them, so this touches no network.
# advice off: git's suggestion is a merge or a rebase, and which of those you
# want is the sentence below, not a wall of hints.
if ! merge_log="$(git -c advice.diverging=false merge --ff-only '@{u}' 2>&1)"; then
  printf '%s\n' "$merge_log" | sed 's/^/    /'
  say "Your branch has commits the remote does not. To put them on top of the"
  say "update instead:  git pull --rebase"
  die "Could not fast-forward."
fi
after="$(git rev-parse HEAD)"

echo
say "What arrived:"
git --no-pager log --oneline "$before..$after" | sed 's/^/    /'
echo

# 4. Launchers --------------------------------------------------------------
# An update can add a dependency or move a file, so the installer runs again.
# With no keys named it keeps the ones stored in the settings, which are the
# ones you chose.
"$DIR/install.sh"

# 5. The running instance ---------------------------------------------------
# It is still running the code from before the pull, which on an update across
# the move into a package is a process still named after the old entry point.
if pgrep -u "$USER_NAME" -f 'dikte(/__main__|)\.py' >/dev/null 2>&1; then
  if [[ -n "$PY" ]] && "$PY" "$ENTRY" restart >/dev/null 2>&1; then
    ok "Restarted, so the new version is the one running"
  else
    warn "Could not restart it; use the tray menu → Restart"
  fi
else
  say "Dikte was not running. Start it with:  dikte"
fi
echo