import {
    CHANGE,
    DotMatrixReg,
    DotMatrixVariant,
    SensorReg,
    SRV_DOT_MATRIX,
} from "../jdom/constants"
import { JDRegisterServer } from "../jdom/servers/registerserver"
import { JDServiceServer } from "../jdom/servers/serviceserver"

export class DotMatrixServer extends JDServiceServer {
    readonly dots: JDRegisterServer<[Uint8Array]>
    readonly rows: JDRegisterServer<[number]>
    readonly columns: JDRegisterServer<[number]>
    readonly brightness: JDRegisterServer<[number]>
    readonly variant: JDRegisterServer<[DotMatrixVariant]>

    constructor(
        columns: number,
        rows: number,
        options?: {
            brightness?: number
            variant?: DotMatrixVariant
        },
    ) {
        super(SRV_DOT_MATRIX)
        const { brightness, variant } = options || {}
        this.dots = this.addRegister(DotMatrixReg.Dots, [new Uint8Array(0)])
        this.rows = this.addRegister(DotMatrixReg.Rows, [rows])
        this.columns = this.addRegister(DotMatrixReg.Columns, [columns])
        if (brightness !== undefined)
            this.brightness = this.addRegister(DotMatrixReg.Brightness, [128])
        if (variant !== undefined)
            this.variant = this.addRegister(DotMatrixReg.Variant, [variant])
        this.rows.skipBoundaryCheck = true
        this.rows.skipErrorInjection = true

        if (variant === DotMatrixVariant.LED)
            this.addRegister<[number]>(SensorReg.StreamingPreferredInterval, [
                50,
            ])

        this.rows.on(CHANGE, this.updateDotsBuffer.bind(this))
        this.columns.on(CHANGE, this.updateDotsBuffer.bind(this))

        this.updateDotsBuffer()
    }

    private updateDotsBuffer() {
        // columns must be byte aligned
        const [rows] = this.rows.values()
        const [columns] = this.columns.values()

        // total bytes needed
        const n = columns * ((rows + 7) >> 3)

        if (this.dots.data?.length !== n) {
            this.dots.data = new Uint8Array(n)
            this.dots.emit(CHANGE)
        }
    }
}