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

# =============================================================================
# phase10_teardown.sh — Reverse local repo remote cutover from phase 10
# Reverts local repos so GitHub is origin again:
#   1. Move Gitea origin -> gitea (if present)
#   2. Move github -> origin
#   3. Set local branch upstreams to origin/<branch> where available
# =============================================================================

SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
source "${SCRIPT_DIR}/lib/common.sh"
source "${SCRIPT_DIR}/lib/phase10_common.sh"

load_env
require_vars GITEA_ORG_NAME GITEA_DOMAIN GITHUB_USERNAME

phase_header 10 "Local Repo Remote Cutover — Teardown"

LOCAL_REPO_ROOT="${PHASE10_LOCAL_ROOT:-/Users/s/development}"
EXPECTED_REPO_COUNT="${PHASE10_EXPECTED_REPO_COUNT:-3}"
INCLUDE_PATHS=()
AUTO_YES=false

if [[ -n "${PHASE10_INCLUDE_PATHS:-}" ]]; then
  # Space-delimited list of extra repo roots to include in phase10 discovery.
  read -r -a INCLUDE_PATHS <<< "${PHASE10_INCLUDE_PATHS}"
fi

for arg in "$@"; do
  case "$arg" in
    --local-root=*) LOCAL_REPO_ROOT="${arg#*=}" ;;
    --expected-count=*) EXPECTED_REPO_COUNT="${arg#*=}" ;;
    --include-path=*) INCLUDE_PATHS+=("${arg#*=}") ;;
    --yes|-y) AUTO_YES=true ;;
    --help|-h)
      cat <<EOF
Usage: $(basename "$0") [options]

Options:
  --local-root=PATH      Root folder containing local repos (default: /Users/s/development)
  --expected-count=N     Require exactly N discovered repos (default: 3, 0 disables)
  --include-path=PATH    Explicit repo root to include (repeatable)
  --yes, -y              Skip confirmation prompt
  --help                 Show this help
EOF
      exit 0
      ;;
    *)
      log_error "Unknown argument: $arg"
      exit 1
      ;;
  esac
done

if ! [[ "$EXPECTED_REPO_COUNT" =~ ^[0-9]+$ ]]; then
  log_error "--expected-count must be a non-negative integer"
  exit 1
fi

if [[ "$AUTO_YES" != "true" ]]; then
  log_warn "This will revert local repo remotes so GitHub is origin again."
  printf 'Continue? [y/N] ' >&2
  read -r confirm
  if [[ "$confirm" != "y" ]] && [[ "$confirm" != "Y" ]]; then
    log_info "Teardown cancelled"
    exit 0
  fi
fi

if ! phase10_discover_local_repos "$LOCAL_REPO_ROOT" "$GITHUB_USERNAME" "$SCRIPT_DIR" 0; then
  exit 1
fi

for include_path in "${INCLUDE_PATHS[@]}"; do
  [[ -z "$include_path" ]] && continue
  if ! phase10_include_repo_path "$include_path" "$GITHUB_USERNAME"; then
    exit 1
  fi
done

phase10_sort_repo_arrays

if ! phase10_enforce_expected_count "$EXPECTED_REPO_COUNT" "$LOCAL_REPO_ROOT"; then
  exit 1
fi

set_tracking_to_origin_where_available() {
  local repo_path="$1" repo_name="$2"
  local branch branch_count
  branch_count=0

  while IFS= read -r branch; do
    [[ -z "$branch" ]] && continue
    branch_count=$((branch_count + 1))

    if git -C "$repo_path" show-ref --verify --quiet "refs/remotes/origin/${branch}"; then
      if git -C "$repo_path" branch --set-upstream-to="origin/${branch}" "$branch" >/dev/null 2>&1; then
        log_success "${repo_name}: branch ${branch} now tracks origin/${branch}"
      else
        log_warn "${repo_name}: could not set upstream for ${branch}"
      fi
    else
      log_warn "${repo_name}: origin/${branch} not found (upstream unchanged)"
    fi
  done < <(git -C "$repo_path" for-each-ref --format='%(refname:short)' refs/heads)

  if [[ "$branch_count" -eq 0 ]]; then
    log_warn "${repo_name}: no local branches found"
  fi
}

ensure_origin_is_github() {
  local repo_path="$1" repo_name="$2" github_url="$3" gitea_url="$4"
  local origin_url github_url_existing gitea_url_existing

  origin_url="$(git -C "$repo_path" remote get-url origin 2>/dev/null || true)"
  github_url_existing="$(git -C "$repo_path" remote get-url github 2>/dev/null || true)"
  gitea_url_existing="$(git -C "$repo_path" remote get-url gitea 2>/dev/null || true)"

  if [[ -n "$origin_url" ]]; then
    if phase10_url_is_github_repo "$origin_url" "$GITHUB_USERNAME" "$repo_name"; then
      git -C "$repo_path" remote set-url origin "$github_url"
      if [[ -n "$github_url_existing" ]]; then
        git -C "$repo_path" remote remove github
      fi
      return 0
    fi

    if phase10_url_is_gitea_repo "$origin_url" "$GITEA_DOMAIN" "$GITEA_ORG_NAME" "$repo_name"; then
      if [[ -z "$gitea_url_existing" ]]; then
        git -C "$repo_path" remote rename origin gitea
      else
        git -C "$repo_path" remote set-url gitea "$gitea_url"
        git -C "$repo_path" remote remove origin
      fi
    else
      log_error "${repo_name}: origin remote is unexpected (${origin_url})"
      return 1
    fi
  fi

  if git -C "$repo_path" remote get-url origin >/dev/null 2>&1; then
    :
  elif [[ -n "$github_url_existing" ]]; then
    git -C "$repo_path" remote rename github origin
  else
    git -C "$repo_path" remote add origin "$github_url"
  fi

  git -C "$repo_path" remote set-url origin "$github_url"

  if git -C "$repo_path" remote get-url github >/dev/null 2>&1; then
    git -C "$repo_path" remote remove github
  fi

  if git -C "$repo_path" remote get-url gitea >/dev/null 2>&1; then
    git -C "$repo_path" remote set-url gitea "$gitea_url"
  fi

  return 0
}

SUCCESS=0
FAILED=0

for i in "${!PHASE10_REPO_NAMES[@]}"; do
  repo_name="${PHASE10_REPO_NAMES[$i]}"
  repo_path="${PHASE10_REPO_PATHS[$i]}"
  github_url="${PHASE10_GITHUB_URLS[$i]}"
  gitea_url="$(phase10_canonical_gitea_url "$GITEA_DOMAIN" "$GITEA_ORG_NAME" "$repo_name")"

  log_info "--- Reverting repo: ${repo_name} (${repo_path}) ---"
  if ! ensure_origin_is_github "$repo_path" "$repo_name" "$github_url" "$gitea_url"; then
    FAILED=$((FAILED + 1))
    continue
  fi

  set_tracking_to_origin_where_available "$repo_path" "$repo_name"
  SUCCESS=$((SUCCESS + 1))
done

printf '\n'
TOTAL=${#PHASE10_REPO_NAMES[@]}
log_info "Results: ${SUCCESS} reverted, ${FAILED} failed (out of ${TOTAL})"

if [[ "$FAILED" -gt 0 ]]; then
  log_error "Phase 10 teardown completed with failures"
  exit 1
fi

log_success "Phase 10 teardown complete"