import cors from "@fastify/cors";
import Fastify, { type FastifyInstance } from "fastify";
import { z } from "zod";
import {
  buildFairwayRoutes,
  EMDEN_HAMM_GRAPH,
  type FairwayGraph,
  type RouteOption,
  type RouteRequest,
  type RouteResult
} from "@watermaps/shared";
import { loadEnv, type ApiEnv } from "./env.js";
import { createCache, type Cache } from "./services/cache.js";
import { appConfig } from "./services/config.js";
import { FairwayService } from "./services/fairways.js";
import { FeatureService } from "./services/features.js";
import { getNearestTideSummary } from "./services/tides.js";
import { getMarineForecast } from "./services/weather.js";
import type { FetchLike } from "./services/http.js";
import {
  getNavigationData,
  type NavigationDataAdapters
} from "./services/navigation-data.js";

export type AppDeps = {
  env?: ApiEnv;
  cache?: Cache;
  fetcher?: FetchLike;
  featureService?: FeatureService;
  fairwayService?: Pick<FairwayService, "getGraphsForRoute" | "close">;
  navigationAdapters?: NavigationDataAdapters;
};

const coordinateSchema = z.object({
  lat: z.number().min(-90).max(90),
  lon: z.number().min(-180).max(180)
});

const routeRequestSchema = z.object({
  start: coordinateSchema,
  destination: coordinateSchema,
  waypoints: z.array(coordinateSchema).max(25).optional(),
  departureTime: z
    .string()
    .refine((value) => Number.isFinite(Date.parse(value)), "departureTime must be an ISO timestamp")
    .optional(),
  vesselProfile: z.object({
    draughtM: z.number().positive().max(15),
    safetyReserveM: z.number().min(0).max(10),
    airDraftM: z.number().positive().max(80).optional(),
    beamM: z.number().positive().max(80).optional(),
    cruiseSpeedKn: z.number().positive().max(80).optional()
  }),
  depthSamples: z
    .array(
      z.object({
        coordinate: coordinateSchema,
        depthM: z.number().nullable()
      })
    )
    .max(500)
    .optional()
}) satisfies z.ZodType<RouteRequest>;

const coordinateQuerySchema = z.object({
  lat: z.coerce.number().min(-90).max(90),
  lon: z.coerce.number().min(-180).max(180),
  at: z
    .string()
    .refine((value) => Number.isFinite(Date.parse(value)), "at must be an ISO timestamp")
    .optional()
});

const featuresQuerySchema = z.object({
  bbox: z
    .string()
    .transform((value, ctx) => {
      const parts = value.split(",").map(Number);
      if (parts.length !== 4 || parts.some((part) => !Number.isFinite(part))) {
        ctx.addIssue({ code: z.ZodIssueCode.custom, message: "bbox must be minLon,minLat,maxLon,maxLat" });
        return z.NEVER;
      }
      return parts as [number, number, number, number];
    }),
  layers: z
    .string()
    .default("seamarks,bridges,locks,harbours")
    .transform((value) =>
      value
        .split(",")
        .map((layer) => layer.trim())
        .filter(Boolean)
    )
});

const navigationQuerySchema = z.object({
  waterways: commaSeparatedQuery(12).optional(),
  stationIds: commaSeparatedQuery(30).optional(),
  lockIds: commaSeparatedQuery(30).optional()
});

export async function buildServer(deps: AppDeps = {}): Promise<FastifyInstance> {
  const env = deps.env ?? loadEnv();
  const cache = deps.cache ?? createCache(env.redisUrl);
  const fetcher = deps.fetcher ?? fetch;
  const featureService = deps.featureService ?? new FeatureService(env);
  const fairwayService =
    deps.fairwayService ??
    new FairwayService({
      cache,
      fetcher,
      liveEnabled: env.liveOsmFairways,
      databaseUrl: env.databaseUrl
    });
  const app = Fastify({
    logger: {
      level: process.env.LOG_LEVEL ?? "info"
    }
  });

  await app.register(cors, {
    origin: true
  });

  app.addHook("onClose", async () => {
    await cache.close();
    await featureService.close();
    await fairwayService.close?.();
  });

  app.get("/health", async () => ({ ok: true, service: "watermaps-api" }));

  app.get("/api/config", async () => appConfig);

  app.get("/api/weather/marine", async (request, reply) => {
    const parsed = coordinateQuerySchema.safeParse(request.query);
    if (!parsed.success) {
      return reply.code(400).send({ error: "invalid_query", details: parsed.error.flatten() });
    }

    return getMarineForecast(parsed.data, { cache, fetcher });
  });

  app.get("/api/tides/nearest", async (request, reply) => {
    const parsed = coordinateQuerySchema.safeParse(request.query);
    if (!parsed.success) {
      return reply.code(400).send({ error: "invalid_query", details: parsed.error.flatten() });
    }

    const summary = await getNearestTideSummary(parsed.data, { cache, fetcher });
    if (!summary) {
      return reply.code(404).send({ error: "no_tide_station_found" });
    }

    return summary;
  });

  app.get("/api/navigation/live", async (request, reply) => {
    const parsed = navigationQuerySchema.safeParse(request.query);
    if (!parsed.success) {
      return reply.code(400).send({ error: "invalid_query", details: parsed.error.flatten() });
    }

    return getNavigationData(parsed.data, {
      cache,
      fetcher,
      adapters: deps.navigationAdapters
    });
  });

  app.get("/api/features", async (request, reply) => {
    const parsed = featuresQuerySchema.safeParse(request.query);
    if (!parsed.success) {
      return reply.code(400).send({ error: "invalid_query", details: parsed.error.flatten() });
    }

    return featureService.getFeatures(parsed.data);
  });

  app.post("/api/routes", async (request, reply) => {
    const parsed = routeRequestSchema.safeParse(request.body);
    if (!parsed.success) {
      return reply.code(400).send({ error: "invalid_route", details: parsed.error.flatten() });
    }

    const dynamicGraphs = await fairwayService.getGraphsForRoute(parsed.data).catch((error) => {
      app.log.warn({ error }, "fairway extraction failed");
      return [];
    });
    const route = buildRouteFromGraphs(parsed.data, dynamicGraphs);
    if (!route) {
      return reply.code(422).send({
        error: "no_fairway_route",
        message:
          "Keine Fahrwasserroute für Start und Ziel gefunden. Setze Punkte näher an ein bekanntes Fahrwasser oder importiere weitere Fahrwasserdaten."
      });
    }

    return route;
  });

  return app;
}

function commaSeparatedQuery(maxItems: number) {
  return z.string().transform((value, ctx) => {
    const items = [...new Set(value.split(",").map((item) => item.trim()).filter(Boolean))];
    if (items.length > maxItems) {
      ctx.addIssue({
        code: z.ZodIssueCode.custom,
        message: `too many values (maximum ${maxItems})`
      });
      return z.NEVER;
    }
    return items;
  });
}

function buildRouteFromGraphs(request: RouteRequest, graphs: FairwayGraph[]) {
  for (const graph of graphs) {
    const routes = buildFairwayRoutes(request, graph);
    if (routes.length > 0) {
      return routeResultWithAlternatives(routes);
    }
  }

  for (const graph of [undefined, EMDEN_HAMM_GRAPH] as const) {
    const routes = graph ? buildFairwayRoutes(request, graph) : buildFairwayRoutes(request);
    if (routes.length > 0) {
      return routeResultWithAlternatives(routes);
    }
  }

  return null;
}

function routeResultWithAlternatives(routes: RouteOption[]): RouteResult {
  const [primary, ...alternatives] = routes;
  if (!primary) {
    throw new Error("routeResultWithAlternatives requires at least one route");
  }

  return {
    ...primary,
    alternatives
  };
}