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| 1 | +import { Router } from "express"; |
| 2 | +import { openapi } from "@neaps/api"; |
| 3 | +import { approximateTideHeightAt } from "./calculations.js"; |
| 4 | +import type { TideExtreme, TideForecastFunction } from "./types.js"; |
| 5 | + |
| 6 | +/** |
| 7 | + * Create Express routes that implement a @neaps/api-compatible API |
| 8 | + * backed by the given tide forecast provider. |
| 9 | + */ |
| 10 | +export function createAdapterRoutes(provider: TideForecastFunction) { |
| 11 | + const router = Router(); |
| 12 | + |
| 13 | + router.get("/openapi.json", (_req, res) => { |
| 14 | + res.json(openapi); |
| 15 | + }); |
| 16 | + |
| 17 | + router.get("/extremes", async (req, res) => { |
| 18 | + const { latitude, longitude, start, end } = req.query; |
| 19 | + |
| 20 | + if (!latitude || !longitude) { |
| 21 | + return res.status(400).json({ message: "latitude and longitude are required" }); |
| 22 | + } |
| 23 | + |
| 24 | + try { |
| 25 | + const result = await provider({ |
| 26 | + position: { |
| 27 | + latitude: Number(latitude), |
| 28 | + longitude: Number(longitude), |
| 29 | + }, |
| 30 | + date: start ? String(start) : undefined, |
| 31 | + }); |
| 32 | + |
| 33 | + const extremes = filterByTimeRange(result.extremes, start, end); |
| 34 | + |
| 35 | + res.json({ |
| 36 | + station: result.station, |
| 37 | + extremes: extremes.map(toNeapsExtreme), |
| 38 | + }); |
| 39 | + } catch (error: unknown) { |
| 40 | + res.status(500).json({ message: (error as Error).message }); |
| 41 | + } |
| 42 | + }); |
| 43 | + |
| 44 | + router.get("/timeline", async (req, res) => { |
| 45 | + const { latitude, longitude, start, end } = req.query; |
| 46 | + |
| 47 | + if (!latitude || !longitude) { |
| 48 | + return res.status(400).json({ message: "latitude and longitude are required" }); |
| 49 | + } |
| 50 | + |
| 51 | + try { |
| 52 | + const result = await provider({ |
| 53 | + position: { |
| 54 | + latitude: Number(latitude), |
| 55 | + longitude: Number(longitude), |
| 56 | + }, |
| 57 | + date: start ? String(start) : undefined, |
| 58 | + }); |
| 59 | + |
| 60 | + const startTime = start ? new Date(String(start)) : new Date(); |
| 61 | + const endTime = end |
| 62 | + ? new Date(String(end)) |
| 63 | + : new Date(startTime.getTime() + 7 * 24 * 60 * 60 * 1000); |
| 64 | + |
| 65 | + const timeline = generateTimeline(result.extremes, startTime, endTime); |
| 66 | + |
| 67 | + res.json({ |
| 68 | + station: result.station, |
| 69 | + timeline, |
| 70 | + }); |
| 71 | + } catch (error: unknown) { |
| 72 | + res.status(500).json({ message: (error as Error).message }); |
| 73 | + } |
| 74 | + }); |
| 75 | + |
| 76 | + // Station endpoints are not supported by non-neaps sources |
| 77 | + router.get("/stations", (_req, res) => { |
| 78 | + res.status(501).json({ message: "Station discovery is not supported by this data source" }); |
| 79 | + }); |
| 80 | + |
| 81 | + router.get("/stations/:source/:id", (_req, res) => { |
| 82 | + res.status(501).json({ message: "Station lookup is not supported by this data source" }); |
| 83 | + }); |
| 84 | + |
| 85 | + router.get("/stations/:source/:id/extremes", (_req, res) => { |
| 86 | + res.status(501).json({ message: "Station lookup is not supported by this data source" }); |
| 87 | + }); |
| 88 | + |
| 89 | + router.get("/stations/:source/:id/timeline", (_req, res) => { |
| 90 | + res.status(501).json({ message: "Station lookup is not supported by this data source" }); |
| 91 | + }); |
| 92 | + |
| 93 | + return router; |
| 94 | +} |
| 95 | + |
| 96 | +/** Convert a TideExtreme to the @neaps/api extreme format */ |
| 97 | +function toNeapsExtreme(e: TideExtreme) { |
| 98 | + return { |
| 99 | + time: e.time, |
| 100 | + level: e.value, |
| 101 | + high: e.type === "High", |
| 102 | + low: e.type === "Low", |
| 103 | + label: e.type, |
| 104 | + }; |
| 105 | +} |
| 106 | + |
| 107 | +function filterByTimeRange( |
| 108 | + extremes: TideExtreme[], |
| 109 | + start: unknown, |
| 110 | + end: unknown |
| 111 | +) { |
| 112 | + let filtered = extremes; |
| 113 | + if (start) { |
| 114 | + const startTime = new Date(String(start)).getTime(); |
| 115 | + filtered = filtered.filter((e) => new Date(e.time).getTime() >= startTime); |
| 116 | + } |
| 117 | + if (end) { |
| 118 | + const endTime = new Date(String(end)).getTime(); |
| 119 | + filtered = filtered.filter((e) => new Date(e.time).getTime() <= endTime); |
| 120 | + } |
| 121 | + return filtered; |
| 122 | +} |
| 123 | + |
| 124 | +/** |
| 125 | + * Generate a timeline of water levels at regular intervals by interpolating |
| 126 | + * between known extremes using sine-eased approximation. |
| 127 | + */ |
| 128 | +function generateTimeline( |
| 129 | + extremes: TideExtreme[], |
| 130 | + start: Date, |
| 131 | + end: Date, |
| 132 | + intervalMinutes = 10 |
| 133 | +) { |
| 134 | + const timeline: { time: string; level: number }[] = []; |
| 135 | + const intervalMs = intervalMinutes * 60 * 1000; |
| 136 | + |
| 137 | + for (let t = start.getTime(); t <= end.getTime(); t += intervalMs) { |
| 138 | + const time = new Date(t); |
| 139 | + try { |
| 140 | + const level = approximateTideHeightAt(extremes, time); |
| 141 | + if (level !== null) { |
| 142 | + timeline.push({ time: time.toISOString(), level }); |
| 143 | + } |
| 144 | + } catch { |
| 145 | + // Skip points outside the range of known extremes |
| 146 | + } |
| 147 | + } |
| 148 | + |
| 149 | + return timeline; |
| 150 | +} |
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