#!/usr/bin/env bash
set -euo pipefail

# Obtain a verified artifact for an exact git commit.
# Build may have happened locally or in CI; this script only reports identity
# after the artifact exists. Does not print tokens.
#
# Usage:
#   obtain.sh [--sha SHA] [--branch NAME] [--root DIR] [--timeout SEC]
#
# BUILD_VENUE (makefile.builder, default local):
#   local  HEAD must be SHA; run `make -f makefile.builder docker` or `deb`
#   ci     wait for this SHA via the project CI_STATUS_SCRIPT, then inspect the image
#
# Exit:
#   0  artifact verified; prints ARTIFACT= / DIGEST= / SHA= / VENUE=
#   1  no pipeline, job failed, inspect failed
#   2  usage / config
#   3  CI status script cannot query (ci venue)

usage() {
  sed -n '2,20p' "$0"
}

sha=
branch=
root=
timeout_sec=1200

while (($#)); do
  case "$1" in
    --sha) sha=$2; shift 2 ;;
    --branch) branch=$2; shift 2 ;;
    --root) root=$2; shift 2 ;;
    --timeout) timeout_sec=$2; shift 2 ;;
    -h|--help) usage; exit 0 ;;
    *) echo "Error: unknown argument: $1" >&2; usage >&2; exit 2 ;;
  esac
done

if [[ -z "$root" ]]; then
  root=$(git rev-parse --show-toplevel 2>/dev/null || true)
fi
if [[ -z "$root" ]]; then
  echo "Error: --root must be a git project" >&2
  exit 2
fi
cd "$root"

if [[ -z "$sha" ]]; then
  sha=$(git rev-parse HEAD)
else
  sha=$(git rev-parse "$sha")
fi

# Load .env.builder without printing values; shell values win. Do not read `.env`.
if [[ -f "$root/.env.builder" ]]; then
  while IFS='=' read -r key value; do
    key=${key%%[[:space:]]*}
    [[ -z "$key" || "$key" == \#* ]] && continue
    if [[ -n "${!key:-}" ]]; then
      continue
    fi
    value=${value%\"}; value=${value#\"}; value=${value%\'}; value=${value#\'}
    [[ -z "$value" ]] && continue
    printf -v "$key" '%s' "$value"
    export "$key"
  done < <(grep -v '^[[:space:]]*$' "$root/.env.builder")
fi

script_dir=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
version_sh=$script_dir/version.sh
wait_ci=$script_dir/wait_ci.sh

venue=${BUILD_VENUE:-}
registry=${DOCKER_REGISTRY:-}
repository=${DOCKER_REPOSITORY:-}
if [[ -f "$root/makefile.builder" ]]; then
  if [[ -z "$venue" ]]; then
    venue=$(make -s -C "$root" -f makefile.builder venue 2>/dev/null || true)
  fi
  if [[ -z "$registry" ]]; then
    registry=$(make -s -C "$root" -f makefile.builder print-DOCKER_REGISTRY 2>/dev/null || true)
  fi
  if [[ -z "$repository" ]]; then
    repository=$(make -s -C "$root" -f makefile.builder print-DOCKER_REPOSITORY 2>/dev/null || true)
  fi
fi
venue=${venue:-local}

docker_tag_for_sha() {
  local tmp tag
  tmp=$(mktemp -d "${TMPDIR:-/tmp}/builder-obtain.XXXXXX")
  git -C "$root" worktree add --detach "$tmp" "$sha" >/dev/null
  if [[ -n "$branch" ]]; then
    tag=$(CI_COMMIT_BRANCH="$branch" "$version_sh" -C "$tmp" --docker)
  else
    tag=$("$version_sh" -C "$tmp" --docker)
  fi
  git -C "$root" worktree remove --force "$tmp" >/dev/null
  printf '%s' "$tag"
}

inspect_image() {
  local image=$1 out digest
  if ! command -v docker >/dev/null 2>&1; then
    echo "Error: docker is required to inspect $image" >&2
    exit 1
  fi
  out=$(docker buildx imagetools inspect "$image" 2>/dev/null \
    || docker manifest inspect "$image" 2>/dev/null \
    || true)
  if [[ -z "$out" ]]; then
    echo "Error: cannot inspect $image" >&2
    exit 1
  fi
  digest=$(printf '%s\n' "$out" | awk '/^Digest:/ {print $2; exit}')
  if [[ -z "$digest" ]]; then
    digest=$(python3 -c 'import json,sys
try:
    d=json.load(sys.stdin)
except Exception:
    sys.exit(0)
print(d.get("digest") or "")' <<<"$out")
  fi
  if [[ -z "$digest" ]]; then
    echo "Error: inspect of $image had no digest" >&2
    exit 1
  fi
  printf '%s' "$digest"
}

case "$venue" in
  ci)
    "$wait_ci" --sha "$sha" --root "$root" --timeout "$timeout_sec"
    if [[ ! -x "$version_sh" ]]; then
      echo "Error: version.sh not found: $version_sh" >&2
      exit 2
    fi
    if [[ -z "$registry" || -z "$repository" ]]; then
      echo "Error: DOCKER_REGISTRY and DOCKER_REPOSITORY are required to inspect the CI image" >&2
      exit 2
    fi
    tag=$(docker_tag_for_sha)
    image="${registry}/${repository}:${tag}"
    digest=$(inspect_image "$image")
    echo "ARTIFACT=$image"
    echo "DIGEST=$digest"
    echo "SHA=$sha"
    echo "VENUE=ci"
    echo "TAG=$tag"
    ;;
  local)
    head=$(git rev-parse HEAD)
    if [[ "$head" != "$sha" ]]; then
      echo "Error: local obtain requires HEAD=$sha (HEAD is $head)" >&2
      exit 2
    fi
    if [[ ! -f "$root/makefile.builder" ]]; then
      echo "Error: no makefile.builder" >&2
      exit 2
    fi
    if make -s -C "$root" -f makefile.builder -n docker >/dev/null 2>&1; then
      make -C "$root" -f makefile.builder docker
      if [[ -n "${IMAGE_TAG:-}" ]]; then
        tag=$IMAGE_TAG
      elif [[ -x "$version_sh" ]]; then
        tag=$("$version_sh" --docker)
      else
        echo "Error: cannot derive IMAGE_TAG" >&2
        exit 2
      fi
      name=$(make -s -C "$root" -f makefile.builder print-PROJECT_NAME 2>/dev/null || basename "$root")
      image="${name}:${tag}"
      if [[ -n "$registry" && -n "$repository" ]]; then
        image="${registry}/${repository}:${tag}"
      fi
      echo "ARTIFACT=$image"
      echo "DIGEST=local"
      echo "SHA=$sha"
      echo "VENUE=local"
      echo "TAG=$tag"
    elif make -s -C "$root" -f makefile.builder -n deb >/dev/null 2>&1; then
      make -C "$root" -f makefile.builder deb
      echo "ARTIFACT=deb"
      echo "SHA=$sha"
      echo "VENUE=local"
    else
      echo "Error: local venue has no docker or deb target" >&2
      exit 2
    fi
    ;;
  *)
    echo "Error: BUILD_VENUE must be local or ci (got ${venue})" >&2
    exit 2
    ;;
esac