/**
 * DTP-17 — CDN reversed-ID URL convention.
 */

import { describe, expect, it } from "@suaveplan/testing/runner";
import type { CdnFallbackConfig } from "../src/index.js";
import {
    buildCdnChunkUrl,
    DEFAULT_CDN_LEVELS,
    DEFAULT_CDN_PADDING,
} from "../src/index.js";

const BASE: CdnFallbackConfig = {
    baseUrl: "https://chunks.example.com",
    pathScheme: "reverse-id",
    levels: DEFAULT_CDN_LEVELS,
    padding: DEFAULT_CDN_PADDING,
};

describe("DTP-17 — reverse-id URL convention", () => {
    it("URL builder produces correct path for various levels and padding values", {
        timeout: 5000,
    }, () => {
        const url = buildCdnChunkUrl(BASE, "abcdef1234567890", 47);
        expect(url).toBe(
            "https://chunks.example.com/0/9/8/abcdef1234567890_000000047.chunk"
        );
    });

    it("levels override changes the directory depth", { timeout: 5000 }, () => {
        const url = buildCdnChunkUrl(
            { ...BASE, levels: 1 },
            "abcdef1234567890",
            0
        );
        expect(url).toBe(
            "https://chunks.example.com/0/abcdef1234567890_000000000.chunk"
        );
    });

    it("levels=0 produces no directory prefix", { timeout: 5000 }, () => {
        const url = buildCdnChunkUrl({ ...BASE, levels: 0 }, "abcdef", 0);
        expect(url).toBe("https://chunks.example.com/abcdef_000000000.chunk");
    });

    it("padding override affects chunk-id zero-padding", {
        timeout: 5000,
    }, () => {
        const url = buildCdnChunkUrl(
            { ...BASE, padding: 4 },
            "abcdef1234567890",
            12
        );
        expect(url).toBe(
            "https://chunks.example.com/0/9/8/abcdef1234567890_0012.chunk"
        );
    });

    it("trailing slash on baseUrl is stripped", { timeout: 5000 }, () => {
        const url = buildCdnChunkUrl(
            { ...BASE, baseUrl: "https://chunks.example.com/" },
            "abcdef1234567890",
            1
        );
        expect(url.startsWith("https://chunks.example.com/0/9/8/")).toBe(true);
    });

    it("identical inputs produce byte-identical URLs", {
        timeout: 5000,
    }, () => {
        const a = buildCdnChunkUrl(BASE, "abcdef", 99);
        const b = buildCdnChunkUrl(BASE, "abcdef", 99);
        expect(a).toBe(b);
    });

    it("rejects empty fileId", { timeout: 5000 }, () => {
        expect(() => buildCdnChunkUrl(BASE, "", 0)).toThrow();
    });

    it("rejects negative chunkId", { timeout: 5000 }, () => {
        expect(() => buildCdnChunkUrl(BASE, "abcdef", -1)).toThrow();
    });

    it("rejects non-integer chunkId", { timeout: 5000 }, () => {
        expect(() => buildCdnChunkUrl(BASE, "abcdef", 1.5)).toThrow();
    });

    it("rejects negative levels", { timeout: 5000 }, () => {
        expect(() =>
            buildCdnChunkUrl({ ...BASE, levels: -1 }, "abcdef", 0)
        ).toThrow();
    });

    it("rejects non-integer levels", { timeout: 5000 }, () => {
        expect(() =>
            buildCdnChunkUrl({ ...BASE, levels: 1.5 }, "abcdef", 0)
        ).toThrow();
    });

    it("rejects levels > fileId length", { timeout: 5000 }, () => {
        expect(() =>
            buildCdnChunkUrl({ ...BASE, levels: 10 }, "abc", 0)
        ).toThrow();
    });

    it("rejects negative padding", { timeout: 5000 }, () => {
        expect(() =>
            buildCdnChunkUrl({ ...BASE, padding: -1 }, "abcdef", 0)
        ).toThrow();
    });

    it("rejects non-integer padding", { timeout: 5000 }, () => {
        expect(() =>
            buildCdnChunkUrl({ ...BASE, padding: 1.5 }, "abcdef", 0)
        ).toThrow();
    });
});