#!/usr/bin/env bash
# gstack-community-restore — restore gstack state from cloud backup
#
# Requires community tier + valid auth token.
# Restores: config, analytics summary, retro history.
# Local config values take precedence on conflicts.
#
# Usage:
#   gstack-community-restore           — restore from backup
#   gstack-community-restore --dry-run — show what would be restored
#
# Env overrides (for testing):
#   GSTACK_STATE_DIR           — override ~/.gstack state directory
#   GSTACK_DIR                 — override auto-detected gstack root
set -euo pipefail

GSTACK_DIR="${GSTACK_DIR:-$(cd "$(dirname "$0")/.." && pwd)}"
STATE_DIR="${GSTACK_STATE_DIR:-$HOME/.gstack}"
CONFIG_FILE="$STATE_DIR/config.yaml"
ANALYTICS_DIR="$STATE_DIR/analytics"
JSONL_FILE="$ANALYTICS_DIR/skill-usage.jsonl"
AUTH_REFRESH="$GSTACK_DIR/bin/gstack-auth-refresh"

# Source Supabase config
if [ -f "$GSTACK_DIR/supabase/config.sh" ]; then
  . "$GSTACK_DIR/supabase/config.sh"
fi
ENDPOINT="${GSTACK_TELEMETRY_ENDPOINT:-}"
ANON_KEY="${GSTACK_SUPABASE_ANON_KEY:-}"

DRY_RUN=false
[ "${1:-}" = "--dry-run" ] && DRY_RUN=true

# ─── Pre-checks ─────────────────────────────────────────────
if ! "$AUTH_REFRESH" --check 2>/dev/null; then
  echo "Not authenticated. Run: gstack auth <email>"
  exit 1
fi

ACCESS_TOKEN="$("$AUTH_REFRESH" 2>/dev/null)"
if [ -z "$ACCESS_TOKEN" ]; then
  echo "Failed to get auth token. Run: gstack auth <email>"
  exit 1
fi

AUTH_JSON="$(cat "$STATE_DIR/auth-token.json" 2>/dev/null || echo "{}")"
USER_ID="$(echo "$AUTH_JSON" | grep -o '"user_id":"[^"]*"' | head -1 | sed 's/"user_id":"//;s/"//')"

if [ -z "$USER_ID" ]; then
  echo "No user_id in auth token. Run: gstack auth <email>"
  exit 1
fi

# ─── Fetch backup from Supabase ──────────────────────────────
echo "Fetching backup..."

BACKUP="$(curl -s --max-time 15 \
  "${ENDPOINT}/installations?installation_id=eq.${USER_ID}&select=config_snapshot,analytics_snapshot,retro_history,last_backup_at,email" \
  -H "apikey: ${ANON_KEY}" \
  -H "Authorization: Bearer ${ACCESS_TOKEN}" \
  2>/dev/null || echo "[]")"

# Check if we got data
if [ "$BACKUP" = "[]" ] || [ -z "$BACKUP" ]; then
  echo "No backup found for your account."
  echo "Run gstack for a while and backup will happen automatically."
  exit 0
fi

# Extract first result (strip array brackets)
BACKUP="$(echo "$BACKUP" | sed 's/^\[//;s/\]$//')"

LAST_BACKUP="$(echo "$BACKUP" | grep -o '"last_backup_at":"[^"]*"' | head -1 | sed 's/"last_backup_at":"//;s/"//')"
echo "Last backup: ${LAST_BACKUP:-unknown}"
echo ""

# ─── Restore config ─────────────────────────────────────────
CONFIG_DATA="$(echo "$BACKUP" | grep -o '"config_snapshot":{[^}]*}' | sed 's/"config_snapshot"://' || true)"

if [ -n "$CONFIG_DATA" ] && [ "$CONFIG_DATA" != "null" ] && [ "$CONFIG_DATA" != "{}" ]; then
  echo "Config snapshot found:"
  # Extract key-value pairs from JSON
  KEYS="$(echo "$CONFIG_DATA" | grep -o '"[^"]*":"[^"]*"' | sed 's/"//g')"

  while IFS=: read -r KEY VALUE; do
    [ -z "$KEY" ] && continue
    EXISTING="$("$GSTACK_DIR/bin/gstack-config" get "$KEY" 2>/dev/null || true)"
    if [ -n "$EXISTING" ]; then
      echo "  $KEY: $EXISTING (keeping local value, backup had: $VALUE)"
    else
      echo "  $KEY: $VALUE (restoring from backup)"
      if [ "$DRY_RUN" = "false" ]; then
        "$GSTACK_DIR/bin/gstack-config" set "$KEY" "$VALUE"
      fi
    fi
  done <<< "$KEYS"
  echo ""
fi

# ─── Restore analytics summary ──────────────────────────────
ANALYTICS_DATA="$(echo "$BACKUP" | grep -o '"analytics_snapshot":{[^}]*}' | sed 's/"analytics_snapshot"://' || true)"

if [ -n "$ANALYTICS_DATA" ] && [ "$ANALYTICS_DATA" != "null" ] && [ "$ANALYTICS_DATA" != "{}" ]; then
  echo "Analytics summary found in backup."
  if [ -f "$JSONL_FILE" ]; then
    LOCAL_LINES="$(wc -l < "$JSONL_FILE" | tr -d ' ')"
    echo "  Local analytics: ${LOCAL_LINES} events (keeping local data)"
  else
    echo "  No local analytics found."
    if [ "$DRY_RUN" = "false" ]; then
      mkdir -p "$ANALYTICS_DIR"
      # Extract recent_events array and write as JSONL
      echo "$ANALYTICS_DATA" | jq -r '.recent_events[] | tojson' > "$JSONL_FILE" 2>/dev/null
      echo "  Restored $(wc -l < "$JSONL_FILE" | tr -d ' ') recent events from backup."
    fi
  fi
  echo ""
fi

# ─── Restore retro history ──────────────────────────────────
RETRO_DATA="$(echo "$BACKUP" | grep -o '"retro_history":\[.*\]' | sed 's/"retro_history"://' || true)"

if [ -n "$RETRO_DATA" ] && [ "$RETRO_DATA" != "null" ] && [ "$RETRO_DATA" != "[]" ]; then
  echo "Retro history found in backup."
  if [ "$DRY_RUN" = "false" ]; then
    # Merge: each retro in the array is a JSON object. Write as retro-restored-N.json
    echo "$RETRO_DATA" | jq -c '.[]' | while read -r RETRO; do
      [ -z "$RETRO" ] && continue
      TS="$(echo "$RETRO" | jq -r .ts 2>/dev/null | tr -d ':-')"
      [ -z "$TS" ] && TS="$(date +%s)"
      RNAME="retro-restored-${TS}-$RANDOM.json"
      echo "$RETRO" > "$STATE_DIR/$RNAME"
    done
    echo "  Retro history merged with local data ($(echo "$RETRO_DATA" | jq 'length') entries restored)."
  fi
  echo ""
fi

if [ "$DRY_RUN" = "true" ]; then
  echo "(dry run — no changes made)"
else
  echo "Restore complete."
fi