import { MCPTool } from 'mcp-framework'
import { z } from 'zod'
import { OBSERVER_CONFIG } from '../config.js'
import { getEquatorialCoordinates, convertToAltAz, EquatorialCoordinates } from '../utils/astronomy.js'
interface EphemerisStreamInput {
objects: string[]
cadenceMinutes?: number
durationMinutes?: number
latitude?: number
longitude?: number
altitude?: number
temperature?: number
pressure?: number
minAltitude?: number
startTime?: string
}
class EphemerisStreamTool extends MCPTool<EphemerisStreamInput> {
name = 'getEphemerisStream'
description = 'Generates a time series of altitude/azimuth for selected objects over a period at a fixed cadence. Useful for live tracking or periodic polling.'
protected schema = {
objects: {
type: z.array(z.string()),
description: 'List of object names or catalog identifiers to track.'
},
cadenceMinutes: {
type: z.number().positive().optional().default(5),
description: 'Sampling cadence in minutes. Default: 5.'
},
durationMinutes: {
type: z.number().positive().optional().default(60),
description: 'Total duration in minutes to generate samples for. Default: 60.'
},
latitude: {
type: z.number().optional(),
description: 'Observer latitude in degrees. Optional.'
},
longitude: {
type: z.number().optional(),
description: 'Observer longitude in degrees. Optional.'
},
altitude: {
type: z.number().optional(),
description: 'Observer altitude in meters. Optional.'
},
temperature: {
type: z.number().optional(),
description: 'Ambient temperature in Celsius. Optional.'
},
pressure: {
type: z.number().optional(),
description: 'Pressure in hPa. Optional.'
},
minAltitude: {
type: z.number().optional().default(0),
description: 'Minimum altitude filter in degrees. Default: 0.'
},
startTime: {
type: z.string().optional(),
description: 'ISO start time for the stream. Defaults to now.'
}
}
async execute(params: EphemerisStreamInput) {
const cadence = params.cadenceMinutes ?? 5
const duration = params.durationMinutes ?? 60
const minAlt = params.minAltitude ?? 0
const start = params.startTime ? new Date(params.startTime) : new Date()
const observer = {
latitude: params.latitude ?? OBSERVER_CONFIG.latitude,
longitude: params.longitude ?? OBSERVER_CONFIG.longitude,
elevation: params.altitude ?? OBSERVER_CONFIG.altitude,
temperature: params.temperature ?? OBSERVER_CONFIG.temperature,
pressure: params.pressure ?? OBSERVER_CONFIG.pressure
}
const frames: any[] = []
for (let m = 0; m <= duration; m += cadence) {
const t = new Date(start.getTime() + m * 60000)
for (const name of params.objects) {
let eq: EquatorialCoordinates
try {
eq = await getEquatorialCoordinates(name, t)
} catch (e: any) {
continue
}
const hor = convertToAltAz(eq, observer, t)
if (hor.altitude < minAlt) continue
frames.push({
object: name,
time: t.toISOString(),
altitude: parseFloat(hor.altitude.toFixed(2)),
azimuth: parseFloat(hor.azimuth.toFixed(2)),
aboveHorizon: hor.altitude > 0,
...(typeof eq.magnitude === 'number' && { apparentMagnitude: eq.magnitude }),
...(eq.constellation && { constellation: eq.constellation }),
...(eq.type && { objectType: eq.type })
})
}
}
frames.sort((a, b) => a.time.localeCompare(b.time) || a.object.localeCompare(b.object))
return {
observer: {
latitude: observer.latitude,
longitude: observer.longitude,
altitude: observer.elevation
},
cadenceMinutes: cadence,
durationMinutes: duration,
suggestedPollIntervalSeconds: cadence * 60,
samples: frames
}
}
}
export default EphemerisStreamTool
