import { parseMatchOutcome, type OpenMatchOutcome } from "./match.js";
import { generateOpenSignature } from "./signature.js";
import { openCommentsToXml } from "./xml.js";

export type OpenCredentials = { appId: string; appSecret: string };

export function openApiBase(): string {
    return (process.env["OPEN_DANMAKU_API_BASE"] ?? "https://api.dandanplay.net").replace(
        /\/+$/,
        "",
    );
}

export function readOpenCredentials(env = process.env): OpenCredentials | null {
    const appId = env["OPEN_DANMAKU_APP_ID"];
    const appSecret = env["OPEN_DANMAKU_APP_SECRET"];
    if (!appId || !appSecret) return null;
    return { appId, appSecret };
}

export function hasOpenCredentials(): boolean {
    return effectiveCredentials() !== null;
}

/** 运行时覆盖凭证（管理员在设置里配置）；null 表示回退环境变量 */
let runtimeCredentials: OpenCredentials | null = null;

export function setOpenCredentials(creds: OpenCredentials | null): void {
    runtimeCredentials = creds;
}

export function effectiveCredentials(): OpenCredentials | null {
    return runtimeCredentials ?? readOpenCredentials();
}

export function openHeaders(path: string, creds: OpenCredentials | null): Record<string, string> {
    const headers: Record<string, string> = { "Content-Type": "application/json" };
    if (!creds) return headers;
    const timestamp = Math.floor(Date.now() / 1000);
    return {
        ...headers,
        "X-AppId": creds.appId,
        "X-Timestamp": String(timestamp),
        "X-Signature": generateOpenSignature(creds.appId, timestamp, path, creds.appSecret),
    };
}

export async function openFetchJson(
    path: string,
    init?: { method?: "POST"; body?: string } | undefined,
): Promise<{ ok: true; json: unknown } | { ok: false; status: number | null; error: string }> {
    const creds = effectiveCredentials();
    try {
        const res = await fetch(`${openApiBase()}${path}`, {
            method: init?.method ?? "GET",
            headers: openHeaders(path, creds),
            ...(init?.body !== undefined ? { body: init.body } : {}),
        });
        if (!res.ok)
            return { ok: false, status: res.status, error: `弹弹play API HTTP ${res.status}` };
        const json: unknown = await res.json();
        const base = json as {
            success?: boolean;
            errorCode?: number;
            errorMessage?: string | null;
            errorDetail?: string | null;
        };
        if (base.success === false || (base.errorCode ?? 0) !== 0) {
            return {
                ok: false,
                status: res.status,
                error: base.errorMessage || base.errorDetail || "弹弹play API 调用失败",
            };
        }
        return { ok: true, json };
    } catch (e) {
        return {
            ok: false,
            status: null,
            error: e instanceof Error ? e.message : "弹弹play API 网络错误",
        };
    }
}

export async function openMatch(
    fileName: string,
    fileSize: number,
    fileHash: string | null,
): Promise<OpenMatchOutcome> {
    const res = await openFetchJson("/api/v2/match", {
        method: "POST",
        body: JSON.stringify({
            fileName,
            fileHash: fileHash ?? "",
            fileSize,
            matchMode: fileHash ? "hashAndFileName" : "fileNameOnly",
        }),
    });
    if (!res.ok) return { ok: false, errorMessage: res.error, isMatched: false, candidates: [] };
    return { ok: true, errorMessage: null, ...parseMatchOutcome(res.json) };
}

export async function openCommentXml(episodeId: number): Promise<string | null> {
    const res = await openFetchJson(`/api/v2/comment/${episodeId}?withRelated=true`);
    if (!res.ok) return null;
    const body = res.json as { comments?: Array<Record<string, unknown>> };
    return openCommentsToXml(body.comments ?? []);
}

export type OpenAnimeBrief = {
    animeId: number;
    animeTitle: string | null;
    type: string | null;
    typeDescription: string | null;
    imageUrl: string | null;
    episodes: OpenEpisodeBrief[];
};

export type OpenEpisodeBrief = {
    episodeId: number;
    episodeTitle: string | null;
    type: string | null;
    typeDescription: string | null;
};

type RawEpisode = {
    episodeId?: number | string;
    episodeTitle?: string | null;
    type?: string | null;
    typeDescription?: string | null;
};

type RawAnime = {
    animeId?: number | string;
    animeTitle?: string | null;
    type?: string | null;
    typeDescription?: string | null;
    imageUrl?: string | null;
    episodes?: RawEpisode[];
};

function num(v: number | string | undefined): number | null {
    const n = typeof v === "number" ? v : Number.parseInt(String(v ?? ""), 10);
    return Number.isFinite(n) ? n : null;
}

function parseEpisode(e: RawEpisode): OpenEpisodeBrief | null {
    const episodeId = num(e.episodeId);
    if (episodeId == null) return null;
    return {
        episodeId,
        episodeTitle: e.episodeTitle ?? null,
        type: e.type ?? null,
        typeDescription: e.typeDescription ?? null,
    };
}

function parseAnime(a: RawAnime): OpenAnimeBrief | null {
    const animeId = num(a.animeId);
    if (animeId == null) return null;
    return {
        animeId,
        animeTitle: a.animeTitle ?? null,
        type: a.type ?? null,
        typeDescription: a.typeDescription ?? null,
        imageUrl: a.imageUrl ?? null,
        episodes: (a.episodes ?? []).map(parseEpisode).filter((x): x is OpenEpisodeBrief => x != null),
    };
}

export type OpenSearchOutcome =
    | { ok: true; animes: OpenAnimeBrief[] }
    | { ok: false; errorMessage: string; animes: [] };

/** GET /api/v2/search/episodes?keyword= — 按关键词搜作品（含集列表） */
export async function openSearchEpisodes(keyword: string): Promise<OpenSearchOutcome> {
    const q = encodeURIComponent(keyword.trim());
    const res = await openFetchJson(`/api/v2/search/episodes?keyword=${q}`);
    if (!res.ok) return { ok: false, errorMessage: res.error, animes: [] };
    const body = res.json as { animes?: RawAnime[]; errorCode?: number };
    const animes = (body.animes ?? [])
        .map(parseAnime)
        .filter((x): x is OpenAnimeBrief => x != null);
    return { ok: true, animes };
}

export type OpenEpisodesOutcome =
    | { ok: true; anime: OpenAnimeBrief | null }
    | { ok: false; errorMessage: string; anime: null };

/** GET /api/v2/episodes/{animeId} — 作品下的集列表 */
export async function openAnimeEpisodes(animeId: number): Promise<OpenEpisodesOutcome> {
    const res = await openFetchJson(`/api/v2/episodes/${animeId}`);
    if (!res.ok) return { ok: false, errorMessage: res.error, anime: null };
    const body = res.json as RawAnime;
    return { ok: true, anime: parseAnime(body) };
}