#!/bin/bash

# Exit on errors
set -e

# Configuration
BACKUP_REPO_PATH="/mnt/backups"
PASSWORD_FILE="/etc/restic-password"
LOG_FILE="/var/log/backup_repo_check.log"

# Ensure the log file exists
mkdir -p "$(dirname "$LOG_FILE")"

# Logging function
log_message() {
    echo "[$(date +'%Y-%m-%d %H:%M:%S')] $1" | tee -a "$LOG_FILE"
}

# Main function to check the backup repository
check_backup_repo() {
    # Ensure the backup repository path exists
    mkdir -p "$BACKUP_REPO_PATH"

    # Validate or create the password file
    if [ ! -f "$PASSWORD_FILE" ]; then
        log_message "Password file not found. Creating a new one with a default password."
        echo "default-password" > "$PASSWORD_FILE"
    fi

    # Export the password and repository path for Restic
    export RESTIC_PASSWORD=$(cat "$PASSWORD_FILE")
    export RESTIC_REPOSITORY="$BACKUP_REPO_PATH"

    # Check if the repository contains files
    if [ "$(find "$BACKUP_REPO_PATH" -mindepth 1 | wc -l)" -gt 0 ]; then
        log_message "Checking the backup repository integrity and consistency."

        # Remove stale locks if they exist
        if [ -d "$BACKUP_REPO_PATH/locks" ] && [ "$(ls -A "$BACKUP_REPO_PATH/locks")" ]; then
            log_message "Stale lock detected in the repository. Removing lock."
            if ! restic -r "$BACKUP_REPO_PATH" unlock; then
                log_message "Failed to remove stale lock. Exiting."
                exit 1
            fi
        fi

        # Perform repository integrity check
        if ! restic -q -r "$BACKUP_REPO_PATH" check --read-data-subset=5%; then
            log_message "Repository integrity check failed. Please investigate."
            exit 1
        fi
        log_message "Backup repository integrity check passed."
    else
        # Initialize a new Restic repository if empty
        log_message "No files found in the backup repository. Initializing a new repository."
        if ! restic init -r "$BACKUP_REPO_PATH"; then
            log_message "Failed to initialize the backup repository. Exiting."
            exit 1
        fi
        log_message "Backup repository initialized successfully."
    fi
}

# Execute the function
check_backup_repo