import { invoke } from '@tauri-apps/api/core'
import { listen, type UnlistenFn } from '@tauri-apps/api/event'

export type InstanceBackupEligibility =
	| 'eligible'
	| 'not_installed'
	| 'symlink_instance'
	| 'direct_linked_instance'
	| 'external_game_directory'
	| 'root_missing'
	| 'root_is_link'

export interface BackupRepositoryStatus {
	path: string
	initialized: boolean
	available: boolean
	stored_size: number
	logical_size: number
	snapshot_count: number
	error: string | null
}

export type BackupExclusionKind = 'file' | 'directory'

export interface BackupExclusion {
	path: string
	kind: BackupExclusionKind
}

export function formatBackupExclusionPath(exclusion: BackupExclusion): string {
	return exclusion.kind === 'directory' ? `${exclusion.path}/` : exclusion.path
}

export interface InstanceBackupConfig {
	instance_id: string
	enabled: boolean
	eligibility: InstanceBackupEligibility
	excluded_paths: BackupExclusion[]
	snapshot_count: number
}

export interface BackupSnapshot {
	id: string
	instance_id: string
	instance_name: string
	created_at: number
	file_count: number
	symlink_count: number
	logical_size: number
	added_size: number
}

export interface BackupDeleteSummary {
	snapshot_count: number
	logical_size: number
}

export interface BackupRestorePreview {
	added_files: number
	modified_files: number
	deleted_files: number
	plan_token: string
}

export type BackupOperationType =
	'create' | 'restore' | 'restore_preview' | 'delete' | 'repository_move'
export type BackupOperationState =
	| 'queued'
	| 'scanning'
	| 'hashing'
	| 'saving'
	| 'validating'
	| 'materializing'
	| 'applying'
	| 'completed'
	| 'cancelled'
	| 'failed'
	| 'interrupted'

export interface BackupOperation {
	id: string
	operation_type: BackupOperationType
	instance_id: string
	snapshot_id?: string
	state: BackupOperationState
	processed_bytes: number
	total_bytes: number
	cancellable: boolean
	cancel_requested: boolean
	error?: string
	created_at: number
	updated_at: number
	finished_at?: number
	restore_preview?: BackupRestorePreview
}

export type BackupProgressStage =
	| 'scanning'
	| 'hashing'
	| 'saving'
	| 'validating'
	| 'copying'
	| 'restoring'
	| 'deleting'
	| 'completed'
	| 'cancelled'
	| 'failed'

export type BackupOperationFinalState = 'completed' | 'cancelled' | 'failed'

export interface BackupProgressEvent {
	operationId: string
	instanceId?: string
	operationType: BackupOperationType
	stage: BackupProgressStage
	processedBytes: number
	totalBytes: number
	finalState?: BackupOperationFinalState
	snapshotId?: string
	message?: string
}

export function canonicalizeBackupExclusions(values: BackupExclusion[]): BackupExclusion[] {
	const normalized = values
		.map((value) => ({ ...value, path: value.path.replaceAll('\\', '/') }))
		.sort(
			(left, right) =>
				left.path.split('/').length - right.path.split('/').length ||
				left.path.localeCompare(right.path),
		)
	const result: BackupExclusion[] = []
	for (const value of normalized) {
		const duplicate = result.find((existing) => existing.path === value.path)
		if (duplicate) {
			if (value.kind === 'directory') duplicate.kind = 'directory'
			continue
		}
		if (
			result.some(
				(parent) => parent.kind === 'directory' && value.path.startsWith(`${parent.path}/`),
			)
		) {
			continue
		}
		result.push(value)
	}
	return result
}

export function getBackupRepositoryStatus(): Promise<BackupRepositoryStatus> {
	return invoke('plugin:instance|instance_get_backup_repository_status')
}

export function moveBackupRepository(destination: string): Promise<string> {
	return invoke('plugin:instance|instance_move_backup_repository', { destination })
}

export function getBackupConfig(instanceId: string): Promise<InstanceBackupConfig> {
	return invoke('plugin:instance|instance_get_backup_config', { instanceId })
}

export function normalizeBackupExclusion(
	instanceId: string,
	selectedPath: string,
	kind: BackupExclusionKind,
): Promise<BackupExclusion> {
	return invoke('plugin:instance|instance_normalize_backup_exclusion', {
		instanceId,
		selectedPath,
		kind,
	})
}

export function enableBackups(
	instanceId: string,
	excludedPaths: BackupExclusion[],
): Promise<InstanceBackupConfig> {
	return invoke('plugin:instance|instance_enable_backups', { instanceId, excludedPaths })
}

export function updateBackupExclusions(
	instanceId: string,
	excludedPaths: BackupExclusion[],
): Promise<InstanceBackupConfig> {
	return invoke('plugin:instance|instance_update_backup_exclusions', {
		instanceId,
		excludedPaths,
	})
}

export function disableBackups(instanceId: string): Promise<void> {
	return invoke('plugin:instance|instance_disable_backups', { instanceId })
}

export function startBackup(instanceId: string): Promise<string> {
	return invoke('plugin:instance|instance_start_backup', { instanceId })
}

export function cancelBackup(operationId: string): Promise<boolean> {
	return invoke('plugin:instance|instance_cancel_backup', { operationId })
}

export function listBackupOperations(
	instanceId?: string,
	activeOnly = false,
): Promise<BackupOperation[]> {
	return invoke('plugin:instance|instance_list_backup_operations', {
		instanceId,
		activeOnly,
	})
}

export function listBackups(instanceId: string): Promise<BackupSnapshot[]> {
	return invoke('plugin:instance|instance_list_backups', { instanceId })
}

export function deleteBackup(snapshotId: string): Promise<void> {
	return invoke('plugin:instance|instance_delete_backup', { snapshotId })
}

export function startBackupRestorePreview(snapshotId: string): Promise<string> {
	return invoke('plugin:instance|instance_get_backup_restore_preview', { snapshotId })
}

export function restoreBackup(snapshotId: string, planToken: string): Promise<string> {
	return invoke('plugin:instance|instance_restore_backup', { snapshotId, planToken })
}

export function getBackupDeleteSummary(instanceId: string): Promise<BackupDeleteSummary> {
	return invoke('plugin:instance|instance_get_backup_delete_summary', { instanceId })
}

export function listenBackupProgress(
	handler: (event: BackupProgressEvent) => void,
): Promise<UnlistenFn> {
	return listen<BackupProgressEvent>('instance_backup_progress', (event) => handler(event.payload))
}