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

# ============================================================================
# build-and-push.sh
#
# Purpose:
# - Build & push Docker images for each service under ./containers/*
# - Branch model: `main` is permanent and tracked by the prod stack
#   (image `:latest`). `dev` is a short-lived branch tracked by the dev
#   stack (image `:dev`); it is recreated from `main` at the start of each
#   cycle and deleted after each release. Tags `vX.Y.Z` cover rollback —
#   no `release/<version>` snapshot branches.
# - Two modes:
#     t (test)    = build & push :dev. Switches to (or creates) the `dev`
#                   branch from `main` if not already on it, commits any
#                   pending changes, and pushes `dev` to origin so the dev
#                   stack picks up the matching compose/config alongside
#                   the :dev image.
#     r (release) = MUST be run from `main`. Build & push :<version>,
#                   :dev, :latest. Fast-forwards `main` against
#                   `origin/main`, merges `dev` into `main` if it exists
#                   (local or remote), creates a `Release vX.Y.Z` commit,
#                   tags it, pushes `main` and the tag, and deletes the
#                   `dev` branch locally and on origin. Version is read
#                   from the top of changelog.md.
#
# Usage:
#   ./build-and-push.sh [mode]
#   - mode = t   -> test build, push :dev only
#   - mode = r   -> release build, version taken from changelog.md
#   - omitted    -> prompt (default: t)
#
# Requirements:
# - docs/changelog.md (relative to repo root), with the most recent release
#   at the top as:
#     ## vX.Y.Z — YYYY-MM-DD
#   (the version is parsed from the first such line)
# - One Dockerfile per service under ./containers/<service>/Dockerfile
#
# ----------------------------------------------------------------------------
# Self-update notice (for humans AND for Claude):
#
# The canonical/master copy of this script lives at:
#   /docker/develop/shared-integrations/tooling/docker-build-and-push/build-and-push.sh
#
# When this script is copied into a project repo, it may drift from master.
# On startup the script compares its own SCRIPT_VERSION to the master copy and
# warns if a newer version exists. It does NOT auto-overwrite (too risky during
# a release run).
#
# CLAUDE INSTRUCTION:
# If you (Claude) are about to invoke this script in a project repo, first
# check whether the master copy at the path above is newer (different
# SCRIPT_VERSION or differing file contents). If so, copy the master over
# the local copy BEFORE running, then proceed. Mention the update to the user.
# ============================================================================

SCRIPT_VERSION="1.7.0"
SCRIPT_MASTER_PATH="/docker/develop/shared-integrations/tooling/docker-build-and-push/build-and-push.sh"

DOCKER_REGISTRY="gitea.oskamp.info"
DOCKER_NAMESPACE="ivooskamp"

CHANGELOG_FILE="docs/changelog.md"
CONTAINERS_DIR="containers"

# --- Self-update check -------------------------------------------------------
# Compare this script to the canonical master copy. If it differs, offer to
# copy master over the local copy and re-exec with the same arguments so the
# build runs against the up-to-date script.
#
# Skip with:  SKIP_SELF_UPDATE=1 ./build-and-push.sh ...
self_update_check() {
  if [[ "${SKIP_SELF_UPDATE:-0}" == "1" ]]; then
    return 0
  fi

  local self_path="${BASH_SOURCE[0]}"
  # Resolve to absolute path so a comparison against itself is detected.
  local self_abs
  self_abs="$(cd "$(dirname "$self_path")" 2>/dev/null && pwd)/$(basename "$self_path")" || self_abs="$self_path"

  if [[ "$self_abs" == "$SCRIPT_MASTER_PATH" ]]; then
    return 0  # We ARE the master copy.
  fi
  if [[ ! -f "$SCRIPT_MASTER_PATH" ]]; then
    return 0  # Master not reachable from this host; silently skip.
  fi

  local master_version reason=""
  master_version="$(grep -m1 -E '^SCRIPT_VERSION=' "$SCRIPT_MASTER_PATH" | sed -E 's/.*"([^"]+)".*/\1/')"

  if [[ -n "$master_version" && "$master_version" != "$SCRIPT_VERSION" ]]; then
    reason="version"
  elif ! cmp -s "$self_abs" "$SCRIPT_MASTER_PATH"; then
    reason="contents"
  else
    return 0  # Identical to master.
  fi

  echo "[WARN] Local build-and-push.sh differs from master."
  if [[ "$reason" == "version" ]]; then
    echo "       local  : $SCRIPT_VERSION"
    echo "       master : $master_version  ($SCRIPT_MASTER_PATH)"
  else
    echo "       Same SCRIPT_VERSION ($SCRIPT_VERSION) but file contents differ."
    echo "       master : $SCRIPT_MASTER_PATH"
  fi

  # Prompt only when stdin is a TTY; in non-interactive runs, abort safely so
  # an unattended release never silently runs against a stale script.
  if [[ ! -t 0 ]]; then
    echo "[ERROR] Non-interactive shell — refusing to auto-update."
    echo "        Re-run interactively, or set SKIP_SELF_UPDATE=1 to bypass,"
    echo "        or update manually:  cp \"$SCRIPT_MASTER_PATH\" \"$self_abs\""
    exit 1
  fi

  local reply
  read -r -p "Update local script from master and re-run? [Y/n] " reply
  reply="${reply:-Y}"
  if [[ ! "$reply" =~ ^[Yy]$ ]]; then
    echo "[INFO] Continuing with local version $SCRIPT_VERSION (not updated)."
    echo ""
    return 0
  fi

  if ! cp "$SCRIPT_MASTER_PATH" "$self_abs"; then
    echo "[ERROR] Failed to copy master to $self_abs (read-only filesystem?)."
    echo "        Continuing with local version $SCRIPT_VERSION."
    echo ""
    return 0
  fi
  chmod +x "$self_abs" 2>/dev/null || true

  echo "[INFO] Updated $self_abs from master. Re-executing..."
  echo ""
  # Re-exec with original arguments. SKIP_SELF_UPDATE=1 prevents an
  # update loop if cp somehow didn't take.
  export SKIP_SELF_UPDATE=1
  exec "$self_abs" "$@"
}
self_update_check "$@"

# --- Input: prompt if missing ------------------------------------------------
MODE="${1:-}"
if [[ -z "${MODE}" ]]; then
  echo "Select build type: [t] test build (push :dev only), [r] release build (default: t)"
  read -r MODE
  MODE="${MODE:-t}"
fi

case "$MODE" in
  t|test)    MODE="t" ;;
  r|release) MODE="r" ;;
  *)
    echo "[ERROR] Unknown mode '$MODE' (use 't' for test or 'r' for release)."
    exit 1
    ;;
esac

# --- Helpers -----------------------------------------------------------------
check_docker_ready() {
  if ! docker info >/dev/null 2>&1; then
    echo "[ERROR] Docker daemon not reachable. Is Docker running and do you have permission to use it?"
    exit 1
  fi
}

ensure_registry_login() {
  local cfg="${HOME}/.docker/config.json"
  if [[ ! -f "$cfg" ]]; then
    echo "[ERROR] Docker config not found at $cfg. Please login:  docker login ${DOCKER_REGISTRY}"
    exit 1
  fi
  if ! grep -q "\"${DOCKER_REGISTRY}\"" "$cfg"; then
    echo "[ERROR] No registry auth found for ${DOCKER_REGISTRY}. Please run:  docker login ${DOCKER_REGISTRY}"
    exit 1
  fi
}

validate_repo_component() {
  local comp="$1"
  if [[ ! "$comp" =~ ^[a-z0-9]+([._-][a-z0-9]+)*$ ]]; then
    echo "[ERROR] Invalid repository component '$comp'."
    echo "        Must match: ^[a-z0-9]+([._-][a-z0-9]+)*$ (lowercase, digits, ., _, - as separators)."
    return 1
  fi
}

validate_tag() {
  local tag="$1"
  local len="${#tag}"
  if (( len < 1 || len > 128 )); then
    echo "[ERROR] Invalid tag length ($len). Must be between 1 and 128 characters."
    return 1
  fi
  if [[ ! "$tag" =~ ^[A-Za-z0-9_][A-Za-z0-9_.-]*$ ]]; then
    echo "[ERROR] Invalid tag '$tag'. Allowed: [A-Za-z0-9_.-], must start with alphanumeric or underscore."
    return 1
  fi
}

# Parse the first "## vX.Y.Z ..." heading from changelog.md.
# Accepts:  ## v1.0.3 — 2026-04-24
#           ## v1.0.3 - 2026-04-24
#           ## v1.0.3
read_version_from_changelog() {
  if [[ ! -f "$CHANGELOG_FILE" ]]; then
    echo "[ERROR] $CHANGELOG_FILE not found in $(pwd)." >&2
    exit 1
  fi
  local line
  # Match lines starting with "## v<digits>.<digits>.<digits>"
  line="$(grep -m1 -E '^##[[:space:]]+v[0-9]+\.[0-9]+\.[0-9]+' "$CHANGELOG_FILE" || true)"
  if [[ -z "$line" ]]; then
    echo "[ERROR] No release heading found in $CHANGELOG_FILE (expected e.g. '## v1.0.3 — 2026-04-24' near the top)." >&2
    exit 1
  fi
  # Extract the vX.Y.Z token
  local version
  version="$(echo "$line" | grep -oE 'v[0-9]+\.[0-9]+\.[0-9]+' | head -n1)"
  if [[ -z "$version" ]]; then
    echo "[ERROR] Could not parse version from line: $line" >&2
    exit 1
  fi
  echo "$version"
}

# --- Preflight ---------------------------------------------------------------
if [[ ! -d "$CONTAINERS_DIR" ]]; then
  echo "[ERROR] '$CONTAINERS_DIR' directory missing. Expected ./${CONTAINERS_DIR}/<service>/ with a Dockerfile."
  exit 1
fi

check_docker_ready
ensure_registry_login
validate_repo_component "$DOCKER_NAMESPACE"

# Informational: show branch and HEAD if this happens to be a git repo.
BRANCH_INFO=""
HEAD_INFO=""
if [[ -d ".git" ]]; then
  BRANCH_INFO="$(git branch --show-current 2>/dev/null || echo unknown)"
  HEAD_INFO="$(git rev-parse --short HEAD 2>/dev/null || echo unknown)"
  echo "[INFO] Repo:             $(pwd)"
  echo "[INFO] Current branch:   $BRANCH_INFO"
  echo "[INFO] HEAD (sha):       $HEAD_INFO"
else
  echo "[INFO] Repo:             $(pwd) (not a git checkout)"
fi

# --- Release preflight (BEFORE any docker work) ------------------------------
# All git-side validation for a release happens here so a wrong-branch / dirty
# tree / stale main / conflicting dev / pre-existing tag aborts the run before
# anything is built or pushed to the registry. dev is merged into main now so
# the version we read from changelog.md reflects the merged state, not main's
# pre-merge state.
VERSION=""
DEV_MERGED=0
if [[ "$MODE" == "r" ]]; then
  if [[ ! -d ".git" ]]; then
    echo "[ERROR] Release mode requires a git checkout."
    exit 1
  fi

  CURRENT_BRANCH="$(git symbolic-ref --short -q HEAD || echo)"
  if [[ "$CURRENT_BRANCH" != "main" ]]; then
    echo "[ERROR] Release build must run from 'main' branch. Current: ${CURRENT_BRANCH:-<detached>}."
    echo "        Switch with:  git checkout main"
    exit 1
  fi

  if ! git diff --quiet HEAD -- || ! git diff --cached --quiet; then
    echo "[ERROR] Working tree has uncommitted changes. Commit or stash them on the appropriate branch before releasing."
    git status --short
    exit 1
  fi

  echo "[INFO] Fetching origin..."
  git fetch origin main
  if git ls-remote --exit-code --heads origin dev >/dev/null 2>&1; then
    git fetch origin dev
  fi

  if ! git merge --ff-only origin/main 2>/dev/null; then
    echo "[ERROR] Local main has diverged from origin/main. Resolve manually before releasing."
    exit 1
  fi

  # Merge dev into main BEFORE reading the version, so changelog.md reflects
  # the bumped state that dev brings in.
  if git show-ref --verify --quiet refs/heads/dev; then
    echo "[INFO] Merging local dev into main..."
    if ! git merge --no-ff dev -m "Release (merge dev)"; then
      echo "[ERROR] Merge of dev into main failed (conflict). Resolve manually and re-run."
      exit 1
    fi
    DEV_MERGED=1
  elif git ls-remote --exit-code --heads origin dev >/dev/null 2>&1; then
    echo "[INFO] Fetching and merging origin/dev into main..."
    git fetch origin dev:dev
    if ! git merge --no-ff dev -m "Release (merge dev)"; then
      echo "[ERROR] Merge of dev into main failed (conflict). Resolve manually and re-run."
      exit 1
    fi
    DEV_MERGED=1
  else
    echo "[INFO] No dev branch found — releasing main as-is."
  fi

  VERSION="$(read_version_from_changelog)"
  echo "[INFO] Release version (from $CHANGELOG_FILE, post-merge): $VERSION"
  validate_tag "$VERSION"
  validate_tag "latest"

  # Tag collision = abort. A re-release of an existing version with different
  # content would silently move what consumers think v0.X.Y points to.
  if git rev-parse -q --verify "refs/tags/${VERSION}" >/dev/null; then
    echo "[ERROR] Tag ${VERSION} already exists locally. Bump $CHANGELOG_FILE to a new version before releasing."
    exit 1
  fi
  if git ls-remote --exit-code --tags origin "refs/tags/${VERSION}" >/dev/null 2>&1; then
    echo "[ERROR] Tag ${VERSION} already exists on origin. Bump $CHANGELOG_FILE to a new version before releasing."
    exit 1
  fi

  # Ask for confirmation so you never accidentally re-push an old version or a wrong one.
  read -r -p "Proceed building & pushing as ${VERSION}? [y/N] " CONFIRM
  CONFIRM="${CONFIRM:-N}"
  if [[ ! "$CONFIRM" =~ ^[Yy]$ ]]; then
    echo "[INFO] Aborted by user. Note: dev has been merged into local main; reset with 'git reset --hard origin/main' if you want to undo."
    exit 0
  fi
else
  echo "[INFO] Test build: only :dev will be pushed."
fi
validate_tag "dev"

# --- Build & push per service ------------------------------------------------
shopt -s nullglob
services=( "$CONTAINERS_DIR"/* )
if [[ ${#services[@]} -eq 0 ]]; then
  echo "[ERROR] No services found under $CONTAINERS_DIR"
  exit 1
fi

BUILT_IMAGES=()

for svc_path in "${services[@]}"; do
  [[ -d "$svc_path" ]] || continue
  svc="$(basename "$svc_path")"
  dockerfile="$svc_path/Dockerfile"

  validate_repo_component "$svc"

  if [[ ! -f "$dockerfile" ]]; then
    echo "[WARNING] Skipping '${svc}': Dockerfile not found in ${svc_path}"
    continue
  fi

  IMAGE_BASE="${DOCKER_REGISTRY}/${DOCKER_NAMESPACE}/${svc}"

  if [[ "$MODE" == "r" ]]; then
    echo "============================================================"
    echo "[INFO] Building ${svc} -> tags: ${VERSION}, dev, latest"
    echo "============================================================"
    docker build \
      -t "${IMAGE_BASE}:${VERSION}" \
      -t "${IMAGE_BASE}:dev" \
      -t "${IMAGE_BASE}:latest" \
      "$svc_path"

    docker push "${IMAGE_BASE}:${VERSION}"
    docker push "${IMAGE_BASE}:dev"
    docker push "${IMAGE_BASE}:latest"

    BUILT_IMAGES+=("${IMAGE_BASE}:${VERSION}" "${IMAGE_BASE}:dev" "${IMAGE_BASE}:latest")
  else
    echo "============================================================"
    echo "[INFO] Test build ${svc} -> tag: dev"
    echo "============================================================"
    docker build -t "${IMAGE_BASE}:dev" "$svc_path"
    docker push "${IMAGE_BASE}:dev"
    BUILT_IMAGES+=("${IMAGE_BASE}:dev")
  fi
done

# --- Summary -----------------------------------------------------------------
echo ""
echo "============================================================"
if [[ "$MODE" == "r" ]]; then
  echo "[SUMMARY] Release build & push complete: $VERSION"
else
  echo "[SUMMARY] Test build & push complete (:dev only)"
fi
if [[ -n "$BRANCH_INFO" ]]; then
  echo "[INFO] Branch: $BRANCH_INFO  HEAD: $HEAD_INFO"
fi
echo "[INFO] Images pushed:"
for img in "${BUILT_IMAGES[@]}"; do
  echo "  - $img"
done
echo "============================================================"
echo ""

# --- Git: release commit + tag + push (release mode only) -------------------
# Preflight (branch, clean tree, ff origin/main, dev merge, tag collision,
# version parse) already ran BEFORE the build. dev is already merged into
# local main. We only need to land the Release commit, tag, and push.
if [[ "$MODE" == "r" ]]; then
  echo "[INFO] Finalising release: version=${VERSION}"

  # Produce a clean Release commit at the tip. Preflight guarantees the working
  # tree was clean at start; any post-build artefacts would be unexpected, so
  # commit with --allow-empty to keep the release marker isolated.
  if git diff --quiet HEAD -- && git diff --cached --quiet; then
    git commit --allow-empty -m "Release ${VERSION}"
  else
    echo "[WARN] Working tree changed during the build — staging and including in release commit."
    git add -A
    git commit -m "Release ${VERSION}"
  fi

  git tag -a "${VERSION}" -m "Release ${VERSION}"

  # Push main first (triggers prod webhook), then the tag.
  git push origin main
  git push origin "refs/tags/${VERSION}"
  echo "[INFO] Pushed main and tag ${VERSION} to origin."

  # Clean up dev branch — local and remote.
  if [[ "$DEV_MERGED" == "1" ]]; then
    if git show-ref --verify --quiet refs/heads/dev; then
      git branch -D dev
      echo "[INFO] Deleted local dev branch."
    fi
    if git ls-remote --exit-code --heads origin dev >/dev/null 2>&1; then
      git push origin --delete dev
      echo "[INFO] Deleted remote dev branch."
    fi
  fi
fi

# --- Git: dev branch commit + push (test mode only) -------------------------
if [[ "$MODE" == "t" ]]; then
  if [[ ! -d ".git" ]]; then
    echo "[WARN] Not a git checkout — skipping dev branch commit/push."
    exit 0
  fi

  CURRENT_BRANCH="$(git symbolic-ref --short -q HEAD || echo)"

  # Ensure we are on the dev branch. Create it if needed.
  if [[ "$CURRENT_BRANCH" != "dev" ]]; then
    if git show-ref --verify --quiet refs/heads/dev; then
      echo "[INFO] Switching to existing local dev branch."
      git checkout dev
    elif git ls-remote --exit-code --heads origin dev >/dev/null 2>&1; then
      echo "[INFO] Checking out remote dev branch."
      git fetch origin dev
      git checkout -b dev origin/dev
    else
      echo "[INFO] Creating new dev branch from main."
      git fetch origin main
      git checkout -b dev origin/main
    fi
  fi

  # Stage and commit if there are changes.
  git add -A
  if git diff --cached --quiet; then
    echo "[INFO] Working tree clean — pushing current HEAD to dev."
  else
    git commit -m "Dev build $(date '+%Y-%m-%d %H:%M')"
  fi

  # Non-force push. Diverged origin/dev fails hard — resolve manually.
  git push -u origin dev
  echo "[INFO] Pushed dev to origin."
fi