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

# =============================================================================
# phase4_migrate_repos.sh — Import repos from GitHub + set up Fedora mirrors
# Depends on: Phase 1 + Phase 2 complete (both Gitea instances running)
# For each repo:
#   1. Import from GitHub → Unraid primary (under org, one-time migration)
#   2. Create pull mirror on Fedora (mirrors Unraid → Fedora on interval)
# Idempotent: skips repos that already exist on either instance.
# =============================================================================

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

load_env
require_vars GITEA_ADMIN_TOKEN GITEA_BACKUP_ADMIN_TOKEN \
             GITEA_INTERNAL_URL GITEA_BACKUP_INTERNAL_URL \
             GITEA_ORG_NAME GITEA_ADMIN_USER GITEA_ADMIN_PASSWORD \
             GITHUB_USERNAME GITHUB_TOKEN \
             REPO_NAMES \
             MIGRATE_ISSUES MIGRATE_LABELS MIGRATE_MILESTONES MIGRATE_WIKI \
             GITEA_BACKUP_MIRROR_INTERVAL

# Migration polling knobs (optional in .env)
MIGRATION_POLL_INTERVAL_SEC="${MIGRATION_POLL_INTERVAL_SEC:-3}"
MIGRATION_POLL_TIMEOUT_SEC="${MIGRATION_POLL_TIMEOUT_SEC:-600}"

if ! [[ "$MIGRATION_POLL_INTERVAL_SEC" =~ ^[1-9][0-9]*$ ]]; then
  log_error "MIGRATION_POLL_INTERVAL_SEC must be a positive integer (seconds)"
  exit 1
fi
if ! [[ "$MIGRATION_POLL_TIMEOUT_SEC" =~ ^[1-9][0-9]*$ ]]; then
  log_error "MIGRATION_POLL_TIMEOUT_SEC must be a positive integer (seconds)"
  exit 1
fi
if (( MIGRATION_POLL_TIMEOUT_SEC < MIGRATION_POLL_INTERVAL_SEC )); then
  log_error "MIGRATION_POLL_TIMEOUT_SEC (${MIGRATION_POLL_TIMEOUT_SEC}) must be >= MIGRATION_POLL_INTERVAL_SEC (${MIGRATION_POLL_INTERVAL_SEC})"
  exit 1
fi

phase_header 4 "Migrate Repos + Fedora Mirrors"

# ---------------------------------------------------------------------------
# Build list of repos from REPO_N_NAME env vars
# Using an array rather than hardcoding 3 loops keeps it flexible.
# ---------------------------------------------------------------------------
read -ra REPOS <<< "$REPO_NAMES"

TOTAL=${#REPOS[@]}
SUCCESS=0
FAILED=0

for repo in "${REPOS[@]}"; do
  log_info "--- Processing repo: ${repo} ---"

  # -------------------------------------------------------------------------
  # Step A: Import from GitHub to Unraid primary (under org)
  # Uses Gitea's migration API which clones the GitHub repo server-side.
  # mirror=false because this is a one-time import — we don't want Gitea
  # to keep pulling from GitHub (GitHub becomes the push mirror target later).
  # -------------------------------------------------------------------------
  log_step "A" "Importing ${repo} from GitHub to Unraid..."

  # Idempotency: check if repo already exists on primary
  if gitea_api GET "/repos/${GITEA_ORG_NAME}/${repo}" >/dev/null 2>&1; then
    log_info "Repo '${GITEA_ORG_NAME}/${repo}' already exists on primary — skipping import"
  else
    # Build migration payload — JSON with all options from .env
    MIGRATE_PAYLOAD=$(jq -n \
      --arg clone_addr "https://github.com/${GITHUB_USERNAME}/${repo}.git" \
      --arg auth_token "$GITHUB_TOKEN" \
      --arg repo_owner "$GITEA_ORG_NAME" \
      --arg repo_name "$repo" \
      --arg service "github" \
      --argjson issues "${MIGRATE_ISSUES}" \
      --argjson labels "${MIGRATE_LABELS}" \
      --argjson milestones "${MIGRATE_MILESTONES}" \
      --argjson wiki "${MIGRATE_WIKI}" \
      '{
        clone_addr: $clone_addr,
        auth_token: $auth_token,
        repo_owner: $repo_owner,
        repo_name: $repo_name,
        service: $service,
        mirror: false,
        issues: $issues,
        labels: $labels,
        milestones: $milestones,
        wiki: $wiki
      }')

    if gitea_api POST "/repos/migrate" "$MIGRATE_PAYLOAD" >/dev/null; then
      log_success "Migration started for ${repo}"
    else
      log_error "Failed to start migration for ${repo}"
      FAILED=$((FAILED + 1))
      continue
    fi

    # Wait for migration to complete — poll until repo has content
    # The migration API returns immediately but cloning happens async.
    # We check for commits to confirm the repo has actual content.
    log_info "Waiting for migration to complete (timeout: ${MIGRATION_POLL_TIMEOUT_SEC}s, interval: ${MIGRATION_POLL_INTERVAL_SEC}s)..."
    local_elapsed=0
    while [[ $local_elapsed -lt $MIGRATION_POLL_TIMEOUT_SEC ]]; do
      COMMITS=$(gitea_api GET "/repos/${GITEA_ORG_NAME}/${repo}/commits?limit=1" 2>/dev/null || echo "[]")
      COMMIT_COUNT=$(printf '%s' "$COMMITS" | jq 'length' 2>/dev/null || echo 0)
      if [[ "$COMMIT_COUNT" -gt 0 ]]; then
        log_success "Repo ${repo} migrated with commits"
        break
      fi
      sleep "$MIGRATION_POLL_INTERVAL_SEC"
      local_elapsed=$((local_elapsed + MIGRATION_POLL_INTERVAL_SEC))
    done

    if [[ $local_elapsed -ge $MIGRATION_POLL_TIMEOUT_SEC ]]; then
      log_error "Timeout waiting for ${repo} migration to complete"
      FAILED=$((FAILED + 1))
      continue
    fi
  fi

  # -------------------------------------------------------------------------
  # Step B: Create pull mirror on Fedora
  # The Fedora instance mirrors the Unraid primary on a schedule. This uses
  # Gitea's migration API with mirror=true, which creates a mirror repo that
  # periodically pulls from the source URL.
  # The mirror authenticates to the primary using admin credentials since
  # the primary's repos may be private.
  # -------------------------------------------------------------------------
  log_step "B" "Creating pull mirror for ${repo} on Fedora..."

  # Idempotency: check if mirror repo already exists on Fedora
  if gitea_backup_api GET "/repos/${GITEA_ADMIN_USER}/${repo}" >/dev/null 2>&1; then
    log_info "Mirror '${GITEA_ADMIN_USER}/${repo}' already exists on Fedora — skipping"
  else
    # The clone URL points to the primary Gitea instance (Unraid)
    MIRROR_PAYLOAD=$(jq -n \
      --arg clone_addr "${GITEA_INTERNAL_URL}/${GITEA_ORG_NAME}/${repo}.git" \
      --arg auth_username "$GITEA_ADMIN_USER" \
      --arg auth_password "$GITEA_ADMIN_PASSWORD" \
      --arg repo_owner "$GITEA_ADMIN_USER" \
      --arg repo_name "$repo" \
      --arg mirror_interval "$GITEA_BACKUP_MIRROR_INTERVAL" \
      '{
        clone_addr: $clone_addr,
        auth_username: $auth_username,
        auth_password: $auth_password,
        repo_owner: $repo_owner,
        repo_name: $repo_name,
        service: "gitea",
        mirror: true,
        mirror_interval: $mirror_interval
      }')

    if gitea_backup_api POST "/repos/migrate" "$MIRROR_PAYLOAD" >/dev/null; then
      log_success "Pull mirror created for ${repo} on Fedora"
    else
      log_error "Failed to create pull mirror for ${repo}"
      FAILED=$((FAILED + 1))
      continue
    fi
  fi

  SUCCESS=$((SUCCESS + 1))
done

# ---------------------------------------------------------------------------
# Summary
# ---------------------------------------------------------------------------
printf '\n'
log_info "Results: ${SUCCESS} succeeded, ${FAILED} failed (out of ${TOTAL})"

if [[ $FAILED -gt 0 ]]; then
  log_error "Some repos failed — check logs above"
  exit 1
fi

log_success "Phase 4 complete — all repos migrated and mirrored"