import type { AutoBackupSettings, Backup } from '@modrinth/utils'

import { useServersFetch } from '../servers-fetch.ts'
import { ServerModule } from './base.ts'

export class BackupsModule extends ServerModule {
	data: Backup[] = []

	async fetch(): Promise<void> {
		this.data = await useServersFetch<Backup[]>(`servers/${this.serverId}/backups`, {}, 'backups')
	}

	async create(backupName: string): Promise<string> {
		const tempId = `temp-${Date.now()}-${Math.random().toString(36).substring(7)}`
		const tempBackup: Backup = {
			id: tempId,
			name: backupName,
			created_at: new Date().toISOString(),
			locked: false,
			automated: false,
			interrupted: false,
			ongoing: true,
			task: { create: { progress: 0, state: 'ongoing' } },
		}
		this.data.push(tempBackup)

		try {
			const response = await useServersFetch<{ id: string }>(`servers/${this.serverId}/backups`, {
				method: 'POST',
				body: { name: backupName },
			})

			const backup = this.data.find((b) => b.id === tempId)
			if (backup) {
				backup.id = response.id
			}

			return response.id
		} catch (error) {
			this.data = this.data.filter((b) => b.id !== tempId)
			throw error
		}
	}

	async rename(backupId: string, newName: string): Promise<void> {
		await useServersFetch(`servers/${this.serverId}/backups/${backupId}/rename`, {
			method: 'POST',
			body: { name: newName },
		})
		await this.fetch()
	}

	async delete(backupId: string): Promise<void> {
		await useServersFetch(`servers/${this.serverId}/backups/${backupId}`, {
			method: 'DELETE',
		})
		await this.fetch()
	}

	async restore(backupId: string): Promise<void> {
		const backup = this.data.find((b) => b.id === backupId)
		if (backup) {
			if (!backup.task) backup.task = {}
			backup.task.restore = { progress: 0, state: 'ongoing' }
		}

		try {
			await useServersFetch(`servers/${this.serverId}/backups/${backupId}/restore`, {
				method: 'POST',
			})
		} catch (error) {
			if (backup?.task?.restore) {
				delete backup.task.restore
			}
			throw error
		}
	}

	async lock(backupId: string): Promise<void> {
		await useServersFetch(`servers/${this.serverId}/backups/${backupId}/lock`, {
			method: 'POST',
		})
		await this.fetch()
	}

	async unlock(backupId: string): Promise<void> {
		await useServersFetch(`servers/${this.serverId}/backups/${backupId}/unlock`, {
			method: 'POST',
		})
		await this.fetch()
	}

	async retry(backupId: string): Promise<void> {
		await useServersFetch(`servers/${this.serverId}/backups/${backupId}/retry`, {
			method: 'POST',
		})
	}

	async updateAutoBackup(autoBackup: 'enable' | 'disable', interval: number): Promise<void> {
		await useServersFetch(`servers/${this.serverId}/autobackup`, {
			method: 'POST',
			body: { set: autoBackup, interval },
		})
	}

	async getAutoBackup(): Promise<AutoBackupSettings> {
		return await useServersFetch(`servers/${this.serverId}/autobackup`)
	}

	downloadBackup(
		backupId: string,
		backupName: string,
	): {
		promise: Promise<void>
		onProgress: (cb: (p: { loaded: number; total: number; progress: number }) => void) => void
		cancel: () => void
	} {
		const progressSubject = new EventTarget()
		const abortController = new AbortController()

		const downloadPromise = new Promise<void>((resolve, reject) => {
			const auth = this.server.general?.node
			if (!auth?.instance || !auth?.token) {
				reject(new Error('Missing authentication credentials'))
				return
			}

			const xhr = new XMLHttpRequest()

			xhr.addEventListener('progress', (e) => {
				if (e.lengthComputable) {
					const progress = e.loaded / e.total
					progressSubject.dispatchEvent(
						new CustomEvent('progress', {
							detail: { loaded: e.loaded, total: e.total, progress },
						}),
					)
				} else {
					// progress = -1 to indicate indeterminate size
					progressSubject.dispatchEvent(
						new CustomEvent('progress', {
							detail: { loaded: e.loaded, total: 0, progress: -1 },
						}),
					)
				}
			})

			xhr.onload = () => {
				if (xhr.status >= 200 && xhr.status < 300) {
					try {
						const blob = xhr.response
						const url = window.URL.createObjectURL(blob)
						const a = document.createElement('a')
						a.href = url
						a.download = `${backupName}.zip`
						document.body.appendChild(a)
						a.click()
						document.body.removeChild(a)
						window.URL.revokeObjectURL(url)
						resolve()
					} catch (error) {
						reject(error)
					}
				} else {
					reject(new Error(`Download failed with status ${xhr.status}`))
				}
			}

			xhr.onerror = () => reject(new Error('Download failed'))
			xhr.onabort = () => reject(new Error('Download cancelled'))

			xhr.open(
				'GET',
				`https://${auth.instance}/modrinth/v0/backups/${backupId}/download?auth=${auth.token}`,
			)
			xhr.responseType = 'blob'
			xhr.send()

			abortController.signal.addEventListener('abort', () => xhr.abort())
		})

		return {
			promise: downloadPromise,
			onProgress: (cb: (p: { loaded: number; total: number; progress: number }) => void) => {
				progressSubject.addEventListener('progress', ((e: CustomEvent) => {
					cb(e.detail)
				}) as EventListener)
			},
			cancel: () => abortController.abort(),
		}
	}
}