#!/bin/bash
set -euo pipefail

STARTING_DIR="/home/azureuser"
cd "$STARTING_DIR"

# === CONFIGURATION ===
DBT_PROJECT="dwh_dbt"
DBT_TARGET="prd"
PROFILE_YML="$STARTING_DIR/.dbt/profiles.yml"

# === Flag defaults ===
SEND_SLACK=false

# === Parse flags ===
while [[ $# -gt 0 ]]; do
  case "$1" in
    -s|--slack)
      SEND_SLACK=true
      shift
      ;;
    -*)
      echo "❌ Unknown option: $1"
      exit 1
      ;;
    *)
      break
      ;;
  esac
done

# === Positional arguments ===
SCHEMAS="$1"
MANIFEST_PATH="$2"
shift 2
IFS=',' read -r -a SCHEMA_ARRAY <<< "$SCHEMAS"

# === Tool check/install ===
install_tool_if_missing() {
  TOOL_CALL_NAME=$1
  TOOL_APT_NAME=$2
  if ! command -v "$TOOL_CALL_NAME" &>/dev/null; then
    echo "🔧 Installing missing tool: $TOOL_APT_NAME"
    sudo apt-get update -qq
    sudo apt-get install -y "$TOOL_APT_NAME"
  else
    echo "✅ $TOOL_APT_NAME is installed"
  fi
}

install_tool_if_missing jq jq
install_tool_if_missing yq yq
install_tool_if_missing psql postgresql-client

# === Slack webhook setup ===
script_dir=$(dirname "$0")
webhooks_file="slack_webhook_urls.txt"
env_file="$script_dir/$webhooks_file"

if [ -f "$env_file" ]; then
  export $(grep -v '^#' "$env_file" | xargs)
else
  echo "Error: $webhooks_file file not found in the script directory."
  exit 1
fi

# === Load DB credentials from profiles.yml ===
echo "🔐 Loading DB credentials from $PROFILE_YML..."
DB_NAME=$(yq e ".${DBT_PROJECT}.outputs.${DBT_TARGET}.dbname" "$PROFILE_YML")
DB_USER=$(yq e ".${DBT_PROJECT}.outputs.${DBT_TARGET}.user" "$PROFILE_YML")
DB_HOST=$(yq e ".${DBT_PROJECT}.outputs.${DBT_TARGET}.host" "$PROFILE_YML")
DB_PORT=$(yq e ".${DBT_PROJECT}.outputs.${DBT_TARGET}.port" "$PROFILE_YML")
export PGPASSWORD=$(yq e ".${DBT_PROJECT}.outputs.${DBT_TARGET}.pass" "$PROFILE_YML")

# === Get list of tables/views from Postgres ===
echo "🗃️  Reading current tables/views from PostgreSQL..."

POSTGRES_OBJECTS=()
for SCHEMA in "${SCHEMA_ARRAY[@]}"; do
  echo "🔎 Scanning schema: $SCHEMA"
  TABLES=$(psql -h "$DB_HOST" -p "$DB_PORT" -U "$DB_USER" -d "$DB_NAME" -Atc "
    SELECT LOWER(table_schema || '.' || table_name)
    FROM information_schema.tables
    WHERE table_schema = '$SCHEMA'
      AND table_type IN ('BASE TABLE', 'VIEW')
      AND table_name NOT LIKE 'pg_%'
    ORDER BY table_schema, table_name;
  ")
  while IFS= read -r tbl; do
    tbl_cleaned=$(echo "$tbl" | tr -d '[:space:]')
    [[ -n "$tbl_cleaned" ]] && POSTGRES_OBJECTS+=("$tbl_cleaned")
  done <<< "$TABLES"
done

POSTGRES_OBJECTS=($(printf "%s\n" "${POSTGRES_OBJECTS[@]}" | sort -u))

# === Parse manifest.json for dbt model output names ===
echo "📦 Extracting model output names from dbt manifest..."

DBT_OBJECTS=()
DBT_ENTRIES=$(jq -r '
  .nodes | to_entries[] |
  select(.value.resource_type == "model" or .value.resource_type == "seed") |
  .value.schema + "." + .value.alias
' "$MANIFEST_PATH")

while IFS= read -r entry; do
  entry_cleaned=$(echo "$entry" | tr -d '[:space:]' | tr '[:upper:]' '[:lower:]')
  [[ -n "$entry_cleaned" ]] && DBT_OBJECTS+=("$entry_cleaned")
done <<< "$DBT_ENTRIES"

DBT_OBJECTS=($(printf "%s\n" "${DBT_OBJECTS[@]}" | sort -u))

# === Compare ===
echo "📊 Comparing DBT models vs Postgres state..."

RELEVANT_MODELS=($(comm -12 <(printf "%s\n" "${POSTGRES_OBJECTS[@]}" | sort) <(printf "%s\n" "${DBT_OBJECTS[@]}" | sort)))
STALE_MODELS=($(comm -23 <(printf "%s\n" "${POSTGRES_OBJECTS[@]}" | sort) <(printf "%s\n" "${DBT_OBJECTS[@]}" | sort)))

# === Output ===
echo ""
echo "✅ Relevant models (in both DB and DBT):"
printf "%s\n" "${RELEVANT_MODELS[@]}" | sort

echo ""
echo "⚠️  Stale models (in DB but NOT in DBT):"
printf "%s\n" "${STALE_MODELS[@]}" | sort

# === Format stale models for Slack ===
if [ "$SEND_SLACK" = true ]; then
    echo "✅ Sending slack message with results."
    if [ ${#STALE_MODELS[@]} -eq 0 ]; then
    SLACK_MSG=":white_check_mark::white_check_mark::white_check_mark: dbt models reviewed. No stale models found in the database! :white_check_mark::white_check_mark::white_check_mark:"
    curl -X POST -H 'Content-type: application/json' \
        --data "{\"text\":\"$SLACK_MSG\"}" \
        "$SLACK_RECEIPT_WEBHOOK_URL"
    else
    SLACK_MSG=":rotating_light::rotating_light::rotating_light: Stale models detected in Postgres (not in dbt manifest): :rotating_light::rotating_light::rotating_light:\n"
    for model in "${STALE_MODELS[@]}"; do
        SLACK_MSG+="- \`$model\`\n"
    done
    curl -X POST -H 'Content-type: application/json' \
        --data "{\"text\":\"$SLACK_MSG\"}" \
        "$SLACK_ALERT_WEBHOOK_URL"
    fi
fi