import { apiRequest, getAppBaseUrl } from './common.ts'

// ============================================================================
// Types
// ============================================================================

/**
 * The only application kind today. Workstation is the operator-facing surface where a
 * canvas or workflow is run as tasks.
 */
export type ApplicationKey = 'workstation'

/**
 * Which prompt version the application runs.
 *
 * `'promoted'` and `'production'` are logical names resolved server-side at create/update time and
 * stored as the concrete version id. Pass a version id to pin the application to it.
 */
export type ApplicationVersionTarget = 'promoted' | 'production' | (string & {})

/**
 * Input field the application exposes. Derived server-side from the target prompt version's
 * variables — do not build it by hand.
 */
export interface ApplicationVariable {
    name: string
    isRequired: boolean
    isMultimodal: boolean
}

export interface ApplicationConfig {
    approvalRequired: boolean
    isHidden: boolean
    variables?: ApplicationVariable[]
}

export interface Application {
    id: string
    key: ApplicationKey
    title: string
    description: string | null
    promptId: string
    /** Always a concrete version id once stored, even when created with `'production'`. */
    usedVersion: string
    config: ApplicationConfig
    createdAt: string
    updatedAt: string
    deletedAt: string | null
}

export interface CreateApplicationPayload {
    title: string
    promptId: string
    usedVersion: ApplicationVersionTarget
    description?: string
    key?: ApplicationKey
    config?: Partial<ApplicationConfig>
}

export interface UpdateApplicationPayload {
    title?: string
    description?: string
    usedVersion?: ApplicationVersionTarget
    config?: Partial<ApplicationConfig>
}

// ============================================================================
// API Functions
// ============================================================================

/**
 * List the workspace's applications.
 */
export async function listApplications(options?: { promptId?: string }): Promise<Application[]> {
    const applications = await apiRequest<Application[] | { data: Application[] }>('/prompt-application')
    const list = Array.isArray(applications) ? applications : applications.data

    return options?.promptId
        ? list.filter(app => app.promptId === options.promptId)
        : list
}

/**
 * Find the workstation application for a canvas or workflow, or null when it has none.
 *
 * A prompt has at most one application per key, so this is unambiguous.
 */
export async function getWorkstation(promptId: string): Promise<Application | null> {
    const applications = await listApplications({ promptId })
    return applications.find(app => app.key === 'workstation') ?? null
}

/**
 * Create a workstation application over a canvas or workflow.
 *
 * `config.variables` is derived server-side from the target version's variables; supplying it is
 * unnecessary. A prompt can only have one application per key — creating a second violates the
 * `(promptId, key)` unique index, so call {@link getWorkstation} first when the app may exist.
 */
export async function createApplication(payload: CreateApplicationPayload): Promise<Application> {
    return apiRequest<Application>('/prompt-application', {
        method: 'POST',
        body: JSON.stringify({
            key: payload.key ?? 'workstation',
            title: payload.title,
            description: payload.description ?? null,
            promptId: payload.promptId,
            usedVersion: payload.usedVersion,
            config: {
                approvalRequired: payload.config?.approvalRequired ?? false,
                isHidden: payload.config?.isHidden ?? false,
            },
        }),
    })
}

/**
 * Create the workstation for a prompt, or update the existing one — the create-or-update the
 * publish flow performs.
 *
 * The prompt must already have a promoted version when `usedVersion` is a logical name. With nothing
 * promoted the API answers `404 Resource not found /prompt-application`, naming the collection rather
 * than the version it could not resolve.
 */
export async function upsertWorkstation(
    promptId: string,
    options: {
        title: string
        usedVersion?: ApplicationVersionTarget
        description?: string
        approvalRequired?: boolean
        isHidden?: boolean
    },
): Promise<Application> {
    const existing = await getWorkstation(promptId)
    const usedVersion = options.usedVersion ?? 'production'

    if (existing) {
        return updateApplication(existing.id, {
            usedVersion,
            config: {
                approvalRequired: options.approvalRequired ?? Boolean(existing.config.approvalRequired),
                isHidden: options.isHidden ?? Boolean(existing.config.isHidden),
            },
        })
    }

    return createApplication({
        title: options.title,
        promptId,
        usedVersion,
        description: options.description,
        config: {
            approvalRequired: options.approvalRequired ?? false,
            isHidden: options.isHidden ?? false,
        },
    })
}

export async function updateApplication(
    applicationId: string,
    payload: UpdateApplicationPayload,
): Promise<Application> {
    return apiRequest<Application>(`/prompt-application/${applicationId}`, {
        method: 'PATCH',
        body: JSON.stringify(payload),
    })
}

export async function deleteApplication(applicationId: string): Promise<void> {
    await apiRequest(`/prompt-application/${applicationId}`, { method: 'DELETE' })
}

/**
 * Resolve the prompt version the application currently runs.
 */
export async function getApplicationTargetVersion(applicationId: string): Promise<{ id: string, title: string }> {
    return apiRequest(`/prompt-application/${applicationId}/targetPromptVersion`)
}

/**
 * Fetch one application.
 *
 * There is no `GET /prompt-application/:id` route, so this filters the list.
 */
export async function getApplication(applicationId: string): Promise<Application | null> {
    const applications = await listApplications()
    return applications.find(app => app.id === applicationId) ?? null
}

/**
 * The application's input fields, as the Workstation form renders them.
 *
 * These are the variable names a task must supply, and `isMultimodal` tells you which are files.
 * The list is derived server-side from the target version's variables — it is not something you set.
 */
export async function getApplicationVariables(applicationId: string): Promise<ApplicationVariable[]> {
    const application = await getApplication(applicationId)

    if (!application)
        throw new Error(`Application ${applicationId} not found`)

    return application.config?.variables ?? []
}

/**
 * Link to the Workstation of the canvas or workflow the application belongs to.
 *
 * Workstation is reached through the prompt, not the application id.
 */
export function getWorkstationUrl(promptId: string): string {
    return `${getAppBaseUrl()}/prompt/${promptId}/workstation`
}