#!/usr/bin/env bash
set -euo pipefail

# ── Resolve GNIZA_DIR ────────────────────────────────────────
GNIZA_DIR="$(cd "$(dirname "$(readlink -f "${BASH_SOURCE[0]}")")/.." && pwd)"
export GNIZA_DIR

# ── Source libraries in dependency order ─────────────────────
source "$GNIZA_DIR/lib/constants.sh"
source "$GNIZA_DIR/lib/utils.sh"
detect_mode
source "$GNIZA_DIR/lib/logging.sh"
source "$GNIZA_DIR/lib/config.sh"
source "$GNIZA_DIR/lib/locking.sh"
source "$GNIZA_DIR/lib/targets.sh"
source "$GNIZA_DIR/lib/remotes.sh"
source "$GNIZA_DIR/lib/backup.sh"
source "$GNIZA_DIR/lib/mysql.sh"
source "$GNIZA_DIR/lib/restore.sh"
source "$GNIZA_DIR/lib/retention.sh"
source "$GNIZA_DIR/lib/schedule.sh"
source "$GNIZA_DIR/lib/notify.sh"
source "$GNIZA_DIR/lib/ssh.sh"
source "$GNIZA_DIR/lib/rclone.sh"
source "$GNIZA_DIR/lib/snapshot.sh"
source "$GNIZA_DIR/lib/transfer.sh"

# ── Help ─────────────────────────────────────────────────────
show_help() {
    cat <<EOF
gniza v${GNIZA4LINUX_VERSION} - Linux Backup Manager

Usage: gniza [OPTIONS] [COMMAND]

Options:
  --cli             Force CLI mode (no TUI)
  --debug           Enable debug logging
  --config=FILE     Override config file path
  --help            Show this help
  --version         Show version

Commands:
  backup            [--target=NAME] [--remote=NAME] [--all]
  restore           --target=NAME [--snapshot=TS] [--remote=NAME] [--dest=DIR] [--folder=PATH]
  targets           list|add|delete|show [--name=NAME] [--folders=PATHS]
  remotes           list|add|delete|show|test [--name=NAME]
  snapshots         list [--target=NAME] [--remote=NAME]
  retention         [--target=NAME] [--remote=NAME] [--all]
  schedule          install|show|remove
  logs              [--last] [--tail=N]
  version

If no command is given, the TUI is launched.
EOF
}

# ── CLI argument parsing ─────────────────────────────────────
FORCE_CLI=false
CONFIG_FILE=""
SUBCOMMAND=""
declare -a SUBCMD_ARGS=()

while [[ $# -gt 0 ]]; do
    case "$1" in
        --cli)
            FORCE_CLI=true
            shift
            ;;
        --debug)
            export GNIZA4LINUX_DEBUG="true"
            shift
            ;;
        --config=*)
            CONFIG_FILE="${1#--config=}"
            shift
            ;;
        --help)
            show_help
            exit 0
            ;;
        --version)
            echo "gniza v${GNIZA4LINUX_VERSION}"
            exit 0
            ;;
        -*)
            # Unknown flags before subcommand are errors
            die "Unknown option: $1 (see --help)"
            ;;
        *)
            SUBCOMMAND="$1"
            shift
            SUBCMD_ARGS=("$@")
            break
            ;;
    esac
done

# ── Initialise ───────────────────────────────────────────────
ensure_dirs

# Load config if it exists
if [[ -n "$CONFIG_FILE" ]]; then
    load_config "$CONFIG_FILE"
elif [[ -f "$CONFIG_DIR/gniza.conf" ]]; then
    load_config
fi

init_logging

# ── Parse subcommand flags helper ────────────────────────────
_parse_flag() {
    local flag="$1"
    shift
    local arg
    for arg in "$@"; do
        if [[ "$arg" == "${flag}="* ]]; then
            echo "${arg#"${flag}="}"
            return 0
        fi
    done
    return 1
}

_has_flag() {
    local flag="$1"
    shift
    local arg
    for arg in "$@"; do
        [[ "$arg" == "$flag" ]] && return 0
    done
    return 1
}

# ── CLI subcommand dispatch ──────────────────────────────────
run_cli() {
    case "${SUBCOMMAND:-}" in
        backup)
            local target="" remote="" all=false
            target=$(_parse_flag "--target" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true
            remote=$(_parse_flag "--remote" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true
            _has_flag "--all" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}" && all=true

            acquire_lock
            trap release_lock EXIT

            if [[ "$all" == "true" || -z "$target" ]]; then
                backup_all_targets "$remote"
            else
                backup_target "$target" "$remote"
            fi
            ;;

        restore)
            local target="" snapshot="" remote="" dest="" folder=""
            target=$(_parse_flag "--target" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true
            snapshot=$(_parse_flag "--snapshot" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true
            remote=$(_parse_flag "--remote" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true
            dest=$(_parse_flag "--dest" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true
            folder=$(_parse_flag "--folder" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true

            [[ -z "$target" ]] && die "restore requires --target=NAME"

            if [[ -z "$remote" ]]; then
                remote=$(list_remotes | head -1)
                [[ -z "$remote" ]] && die "No remotes configured"
            fi

            if [[ -n "$folder" ]]; then
                restore_folder "$target" "$folder" "${snapshot:-latest}" "$remote" "$dest"
            else
                restore_target "$target" "${snapshot:-latest}" "$remote" "$dest"
            fi
            ;;

        targets)
            local action="${SUBCMD_ARGS[0]:-list}"
            local name="" folders=""
            name=$(_parse_flag "--name" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true
            folders=$(_parse_flag "--folders" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true

            case "$action" in
                list)
                    local targets; targets=$(list_targets)
                    if [[ -z "$targets" ]]; then
                        echo "No targets configured."
                    else
                        echo "$targets"
                    fi
                    ;;
                add)
                    [[ -z "$name" ]] && die "targets add requires --name=NAME"
                    [[ -z "$folders" ]] && die "targets add requires --folders=PATHS"
                    create_target "$name" "$folders"
                    ;;
                delete)
                    [[ -z "$name" ]] && die "targets delete requires --name=NAME"
                    delete_target "$name"
                    ;;
                show)
                    [[ -z "$name" ]] && die "targets show requires --name=NAME"
                    load_target "$name"
                    echo "TARGET_NAME=$TARGET_NAME"
                    echo "TARGET_FOLDERS=$TARGET_FOLDERS"
                    echo "TARGET_EXCLUDE=$TARGET_EXCLUDE"
                    echo "TARGET_REMOTE=$TARGET_REMOTE"
                    echo "TARGET_RETENTION=$TARGET_RETENTION"
                    echo "TARGET_PRE_HOOK=$TARGET_PRE_HOOK"
                    echo "TARGET_POST_HOOK=$TARGET_POST_HOOK"
                    echo "TARGET_ENABLED=$TARGET_ENABLED"
                    echo "TARGET_MYSQL_ENABLED=$TARGET_MYSQL_ENABLED"
                    echo "TARGET_MYSQL_MODE=$TARGET_MYSQL_MODE"
                    echo "TARGET_MYSQL_DATABASES=$TARGET_MYSQL_DATABASES"
                    echo "TARGET_MYSQL_EXCLUDE=$TARGET_MYSQL_EXCLUDE"
                    echo "TARGET_MYSQL_USER=$TARGET_MYSQL_USER"
                    echo "TARGET_MYSQL_PASSWORD=****"
                    echo "TARGET_MYSQL_HOST=$TARGET_MYSQL_HOST"
                    echo "TARGET_MYSQL_PORT=$TARGET_MYSQL_PORT"
                    echo "TARGET_MYSQL_EXTRA_OPTS=$TARGET_MYSQL_EXTRA_OPTS"
                    ;;
                *)
                    die "Unknown targets action: $action (expected list|add|delete|show)"
                    ;;
            esac
            ;;

        remotes)
            local action="${SUBCMD_ARGS[0]:-list}"
            local name=""
            name=$(_parse_flag "--name" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true

            case "$action" in
                list)
                    local remotes; remotes=$(list_remotes)
                    if [[ -z "$remotes" ]]; then
                        echo "No remotes configured."
                    else
                        echo "$remotes"
                    fi
                    ;;
                add)
                    [[ -z "$name" ]] && die "remotes add requires --name=NAME"
                    echo "Use the TUI or manually create $CONFIG_DIR/remotes.d/${name}.conf"
                    ;;
                delete)
                    [[ -z "$name" ]] && die "remotes delete requires --name=NAME"
                    local conf="$CONFIG_DIR/remotes.d/${name}.conf"
                    [[ ! -f "$conf" ]] && die "Remote config not found: $conf"
                    rm -f "$conf"
                    log_info "Deleted remote config: $conf"
                    ;;
                show)
                    [[ -z "$name" ]] && die "remotes show requires --name=NAME"
                    load_remote "$name"
                    echo "REMOTE_TYPE=$REMOTE_TYPE"
                    echo "REMOTE_HOST=${REMOTE_HOST:-}"
                    echo "REMOTE_PORT=$REMOTE_PORT"
                    echo "REMOTE_USER=$REMOTE_USER"
                    echo "REMOTE_AUTH_METHOD=$REMOTE_AUTH_METHOD"
                    echo "REMOTE_BASE=$REMOTE_BASE"
                    echo "BWLIMIT=$BWLIMIT"
                    echo "RETENTION_COUNT=$RETENTION_COUNT"
                    ;;
                test)
                    [[ -z "$name" ]] && die "remotes test requires --name=NAME"
                    validate_remote "$name"
                    echo "Remote '$name' is valid."
                    ;;
                *)
                    die "Unknown remotes action: $action (expected list|add|delete|show|test)"
                    ;;
            esac
            ;;

        snapshots)
            local action="${SUBCMD_ARGS[0]:-list}"
            local target="" remote=""
            target=$(_parse_flag "--target" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true
            remote=$(_parse_flag "--remote" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true

            case "$action" in
                list)
                    if [[ -z "$remote" ]]; then
                        remote=$(list_remotes | head -1)
                        [[ -z "$remote" ]] && die "No remotes configured"
                    fi
                    _save_remote_globals
                    load_remote "$remote" || die "Failed to load remote: $remote"
                    if [[ -n "$target" ]]; then
                        list_remote_snapshots "$target"
                    else
                        local targets; targets=$(list_targets)
                        while IFS= read -r t; do
                            [[ -z "$t" ]] && continue
                            echo "=== $t ==="
                            list_remote_snapshots "$t" || true
                        done <<< "$targets"
                    fi
                    _restore_remote_globals
                    ;;
                *)
                    die "Unknown snapshots action: $action (expected list)"
                    ;;
            esac
            ;;

        retention)
            local target="" remote="" all=false
            target=$(_parse_flag "--target" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true
            remote=$(_parse_flag "--remote" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true
            _has_flag "--all" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}" && all=true

            if [[ -z "$remote" ]]; then
                remote=$(list_remotes | head -1)
                [[ -z "$remote" ]] && die "No remotes configured"
            fi
            _save_remote_globals
            load_remote "$remote" || die "Failed to load remote: $remote"

            if [[ "$all" == "true" || -z "$target" ]]; then
                local targets; targets=$(list_targets)
                while IFS= read -r t; do
                    [[ -z "$t" ]] && continue
                    enforce_retention "$t"
                done <<< "$targets"
            else
                enforce_retention "$target"
            fi
            _restore_remote_globals
            ;;

        schedule)
            local action="${SUBCMD_ARGS[0]:-show}"
            case "$action" in
                install) install_schedules ;;
                show)    show_schedules ;;
                remove)  remove_schedules ;;
                *)       die "Unknown schedule action: $action (expected install|show|remove)" ;;
            esac
            ;;

        logs)
            local last=false tail_n=""
            _has_flag "--last" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}" && last=true
            tail_n=$(_parse_flag "--tail" "${SUBCMD_ARGS[@]+"${SUBCMD_ARGS[@]}"}") || true

            local log_dir="${LOG_DIR}"
            if [[ "$last" == "true" ]]; then
                local latest; latest=$(ls -t "$log_dir"/gniza-*.log 2>/dev/null | head -1)
                if [[ -z "$latest" ]]; then
                    echo "No log files found."
                else
                    if [[ -n "$tail_n" ]]; then
                        tail -n "$tail_n" "$latest"
                    else
                        cat "$latest"
                    fi
                fi
            else
                ls -lt "$log_dir"/gniza-*.log 2>/dev/null || echo "No log files found."
            fi
            ;;

        version)
            echo "gniza v${GNIZA4LINUX_VERSION}"
            ;;

        "")
            show_help
            ;;

        *)
            die "Unknown command: $SUBCOMMAND (see --help)"
            ;;
    esac
}

# ── Mode selection ───────────────────────────────────────────
if [[ "$SUBCOMMAND" == "web" || " $* " == *" --web "* ]]; then
    # Web GUI mode
    PYTHONPATH="$GNIZA_DIR:${PYTHONPATH:-}" exec python3 -m tui --web "$@"
elif [[ -n "$SUBCOMMAND" ]]; then
    # Explicit subcommand: always CLI
    run_cli
elif [[ "$FORCE_CLI" == "true" ]]; then
    run_cli
elif python3 -c "import textual" 2>/dev/null && [[ -t 1 ]]; then
    # Python Textual TUI mode
    PYTHONPATH="$GNIZA_DIR:${PYTHONPATH:-}" exec python3 -m tui "$@"
else
    # Fallback to CLI help
    run_cli
fi