#!/bin/bash

set -euo pipefail
trap 'echo "Error on line $LINENO. Exiting."' ERR

# -- CONFIGURATION --

source .env

OLD_CONTAINER_DISEASE_LIST="disnet-disease_list_available_database-mysql84-container"
OLD_CONTAINER_USERS="disnet-users_database-mysql84-container"

SOURCE_CONTAINERS=("$OLD_CONTAINER_DISEASE_LIST" "$OLD_CONTAINER_USERS")

NEW_CONTAINER="disnet-diseases_database-mysql84-container"
ROOT_PASSWORD="${ROOT_PASSWORD}"
ROOT_USER="root"

ALL_SCHEMAS=("addb" "disnetdb")

declare -A SCHEMA_CONTAINER_MAP=(
  ["addb"]=$OLD_CONTAINER_DISEASE_LIST
  ["disnetdb"]=$OLD_CONTAINER_USERS
)

volume_common_path="/var/local/docker/disnet/volumes/mysql/"

declare -A CONTAINER_VOLUME_MAP=(
  [$OLD_CONTAINER_DISEASE_LIST]="${volume_common_path}disnet-disease_list_available_database-mysql8upgrade"
  [$OLD_CONTAINER_USERS]="${volume_common_path}disnet-users_database-mysql8upgrade"
)

# --- FUNCTIONS ---

run_unification() {
    echo -e "\033[1mStarting database unification process...\033[0m"

    echo " - Enabling log_bin_trust_function_creators..."
    docker exec -i $NEW_CONTAINER bash -c "MYSQL_PWD=$ROOT_PASSWORD mysql -u$ROOT_USER -e \"SET GLOBAL log_bin_trust_function_creators = 1;\""

    # For each schema, dump and import
    for schema in "${SCHEMAS[@]}"
    do
        echo "Processing schema: $schema"
        SRC_CONTAINER="${SCHEMA_CONTAINER_MAP[$schema]}"

        echo " - Creating $schema in new container..."
        docker exec -i $NEW_CONTAINER bash -c "MYSQL_PWD=$ROOT_PASSWORD mysql -u$ROOT_USER -e \"CREATE DATABASE IF NOT EXISTS $schema;\""

        echo " - Dumping and importing $schema..."
        start_dump=$(date +%s)

        docker exec "$SRC_CONTAINER" bash -c "MYSQL_PWD=$ROOT_PASSWORD mysqldump -u$ROOT_USER --routines --triggers --events $schema" \
        | docker exec -i $NEW_CONTAINER bash -c "MYSQL_PWD=$ROOT_PASSWORD mysql -u$ROOT_USER $schema"

        end_dump=$(date +%s)
        dump_duration=$((end_dump - start_dump))
        hours=$((dump_duration / 3600))
        minutes=$(((dump_duration % 3600) / 60))
        seconds=$((dump_duration % 60))
        printf "\033[1m%s imported successfully in %02dh:%02dm:%02ds\033[0m\n" "$schema" $hours $minutes $seconds

    done

    echo " - Disabling log_bin_trust_function_creators..."
    docker exec -i $NEW_CONTAINER bash -c "MYSQL_PWD=$ROOT_PASSWORD mysql -u$ROOT_USER -e \"SET GLOBAL log_bin_trust_function_creators = 0;\""

    echo "Database unification completed!"
}

create_users_and_grants() {
    echo -e "\033[1mStarting user creation and grants...\033[0m"

    for SRC_CONTAINER in "${SOURCE_CONTAINERS[@]}"; do

        echo "Extracting users from $SRC_CONTAINER"

        readarray -t user_host_pairs < <(docker exec "$SRC_CONTAINER" bash -c "MYSQL_PWD=$ROOT_PASSWORD mysql -u$ROOT_USER -N -B -e \"
        SELECT user, host FROM mysql.user WHERE user NOT IN ('root', 'mysql.sys', 'mysql.session', 'mysql.infoschema'); \"")


        for entry in "${user_host_pairs[@]}"; do
            read username host <<< "$entry"
            env_var_name=$(echo "${username}_PASSWORD" | tr '[:lower:]' '[:upper:]')
            
            if [ -z "${!env_var_name:-}" ]; then
                echo " - No password found for $username (expected ${env_var_name} variable in .env file). Skipping."
                continue
            fi
        
            password="${!env_var_name}"
            
            echo " - Creating user '$username'@'$host'..."
            
            docker exec -i "$NEW_CONTAINER" bash -c "MYSQL_PWD=$ROOT_PASSWORD mysql -u$ROOT_USER -e \"
            CREATE USER IF NOT EXISTS '$username'@'$host' IDENTIFIED BY '$password';\""

            user_host="'$username'@'$host'"
            
            grants=$(docker exec "$SRC_CONTAINER" bash -c "MYSQL_PWD=$ROOT_PASSWORD mysql -u$ROOT_USER -N -B -e \"
            SHOW GRANTS FOR $user_host;\"")

            echo " - Applying grants for user $user_host"
            while IFS= read -r grant; do
                if [[ "$grant" == "GRANT USAGE ON *.* TO"* ]]; then
                    continue
                fi

                escaped_grant=$(printf "%q" "$grant")
                docker exec "$NEW_CONTAINER" bash -c "MYSQL_PWD=$ROOT_PASSWORD mysql -u$ROOT_USER -e $escaped_grant"

            
            done <<< "$grants"

            docker exec "$NEW_CONTAINER" bash -c "MYSQL_PWD=$ROOT_PASSWORD mysql -u$ROOT_USER -e \"FLUSH PRIVILEGES;\""

        done
    done
}

delete_containers() {

    echo -e "\033[1mStarting deletion of old containers...\033[0m"

    for SRC_CONTAINER in "${SOURCE_CONTAINERS[@]}"; do

        echo "Deleting container $SRC_CONTAINER"
        docker stop $SRC_CONTAINER
        docker rm -f $SRC_CONTAINER

        VOLUME_DIR="${CONTAINER_VOLUME_MAP[$SRC_CONTAINER]}"
        echo "Deleting volume $VOLUME_DIR"
        sudo rm -r $VOLUME_DIR

    done
}


# --- MAIN EXECUTION ---

MODE="all"
SCHEMAS=()

if [[ $# -ge 1 ]]; then
    case "$1" in
        users)
            MODE="users"
            shift
            ;;
        unify)
            MODE="unify"
            shift
            SCHEMAS=("$@")
            ;;
        *)
            echo "Unrecognized command: $1"
            echo "Usage:"
            echo "  $0                   # Unify all schemas, create users with permissions and delete old containers"
            echo "  $0 unify s1 s2 ...   # Unify only selected schemas and create users with permissions and delete old containers"
            echo "  $0 users             # Only create users with permissions"
            exit 1
            ;;
    esac
fi

if [[ "$MODE" == "users" ]]; then
    create_users_and_grants
    exit 0
fi

# Set default schemas if none specified
if [[ "$MODE" == "all" || ${#SCHEMAS[@]} -eq 0 ]]; then
  SCHEMAS=("${ALL_SCHEMAS[@]}")
fi

run_unification
create_users_and_grants
delete_containers