#!/bin/bash

#-----------------------------------------------------------------------------------------------
# --------------------- Common Shared Functions for Unraid Scripts -----------------------------
#-----------------------------------------------------------------------------------------------
# This file contains ONLY reusable logic.
# No code should execute on load — only functions.
# All user configuration lives in Master.conf
#-----------------------------------------------------------------------------------------------

#-----------------------------------------------------------------------------------------------
# Load Master.conf
#-----------------------------------------------------------------------------------------------
#-----------------------------------------------------------------------------------------------
# Load Master.conf reliably
#-----------------------------------------------------------------------------------------------
# Load Master.conf
load_master_conf() {
    # Hardcode the full path to your Master.conf
    local master_conf="/mnt/user/appdata/unraid_scripts/Master.conf"

    if [ -f "$master_conf" ]; then
        source "$master_conf"
        echo "Loaded Master.conf from $master_conf"
    else
        echo "Error: Master.conf not found at $master_conf"
        exit 1
    fi
}

# Parse CLI arguments (flags + VAR=value overrides)
parse_args() {
    DRY_RUN=${DRY_RUN:-false}
    for ARG in "$@"; do
        if [[ "$ARG" == *=* ]]; then
            local VAR_NAME="${ARG%%=*}"
            local VAR_VALUE="${ARG#*=}"
            if declare -p "$VAR_NAME" &>/dev/null; then
                printf -v "$VAR_NAME" '%s' "$VAR_VALUE"
                echo "Overriding $VAR_NAME -> $VAR_VALUE"
            else
                echo "Warning: Unknown variable $VAR_NAME, ignoring."
            fi
        else
            case "$ARG" in
                --dry-run|-n) DRY_RUN=true ;;
                --help|-h)
                    echo "Usage: script [--dry-run|-n] [VAR=value ...]"
                    exit 0 ;;
                *) echo "Warning: Unknown argument $ARG" ;;
            esac
        fi
    done
}

# Validate integer
validate_int() {
    local name="$1"
    local value="$2"
    if ! [[ "${value:-}" =~ ^[0-9]+$ ]]; then
        echo "Error: $name must be a non-negative integer."
        exit 1
    fi
}

# Require variable to be set
require_var() {
    local var="$1"
    if [[ -z "${!var:-}" ]]; then
        echo "Error: Required variable $var is not set."
        exit 1
    fi
}

# Detect local/remote host and SSH key
detect_hosts() {
    LOCAL_HOSTNAME="$(hostname)"
    if [[ "$LOCAL_HOSTNAME" == "$HOST1" ]]; then
        LOCAL_SERVER_NAME="$HOST1"
        REMOTE_SERVER_NAME="$HOST2"
    elif [[ "$LOCAL_HOSTNAME" == "$HOST2" ]]; then
        LOCAL_SERVER_NAME="$HOST2"
        REMOTE_SERVER_NAME="$HOST1"
    else
        echo "Error: Local hostname ($LOCAL_HOSTNAME) not recognized."
        exit 1
    fi
    echo "Local server: $LOCAL_SERVER_NAME"
    echo "Remote server: $REMOTE_SERVER_NAME"

    # Resolve Tailscale IP
    REMOTE_SERVER=$(tailscale ip -4 "$REMOTE_SERVER_NAME" 2>/dev/null)
    if [[ -z "$REMOTE_SERVER" ]]; then
        echo "Error: Could not resolve Tailscale IP for $REMOTE_SERVER_NAME"
        exit 1
    fi
    echo "Resolved $REMOTE_SERVER_NAME → $REMOTE_SERVER"

    # SSH key lookup
    KEY_ID="$LOCAL_SERVER_NAME|$REMOTE_SERVER_NAME"
    if [[ -n "${SSH_KEYS[$KEY_ID]}" ]]; then
        SSH_KEY="${SSH_KEYS[$KEY_ID]}"
    else
        echo "Error: No SSH key defined for $LOCAL_SERVER_NAME → $REMOTE_SERVER_NAME"
        exit 1
    fi
    echo "Using SSH key: $SSH_KEY"
}