#! /bin/bash

set -xe

source ./scripts/env.sh ./.env.schema

base="$1"
head_arg="$2"
head=$(git show --format=format:%h -q | xargs)

if [[ -n "$head_arg" ]]; then
  head="$head_arg"
fi;

migration="./migrations/${base}_to_${head}.sql"

db() {
  echo -n "postgresql+pg8000:///dnim?port=$1&user=$POSTGRES_USER&password=$POSTGRES_PASSWORD"
}

if [[ -z "$base" ]] || [[ -z "$head" ]]; then
  echo "revisions to diff are required ex. ./scripts/diff.sh abc bcd" 1>&2;
  exit 1;
fi

set +e
schema_changed=$(git diff --quiet "$base" "$head" -- ./schema)
schema_changed_exit=$?
set -e
if [[ "$schema_changed_exit" = "0" ]]; then
  echo ""
  exit 0;
fi;

if [[ ! -f "$migration" ]]; then
  ./scripts/build.sh base "$base" 1>&2 || (echo "base failed to build" && exit 1)
  ./scripts/build.sh head "$head" 1>&2 || (echo "head failed to build" && exit 1)

  until pg_isready --quiet -p 5432 && pg_isready --quiet -p 5433; do true; done;

  migra --unsafe "$(db 5432)" "$(db 5433)" || echo "migra exited with code $?. this is /probably/ fine" 1>&2
else
  cat "$migration"
fi