import { defineTool, ToolError } from 'libllmorbiter';
import * as dbCompanySetting from '../db/companysetting.js';

const SERPER_SEARCH_ENDPOINT = 'https://google.serper.dev/search';
const SEARCH_TIMEOUT_MS = 15_000;

/**
 * Normalizes user/model-supplied time filter into Google's qdr syntax.
 * Supported:
 *  - "day" / "24h" / "d" -> "qdr:d"
 *  - "week" / "w" -> "qdr:w"
 *  - "month" / "m" -> "qdr:m"
 *  - "year" / "y" -> "qdr:y"
 *  - "hour" / "h" -> "qdr:h"
 *
 * @param {string|null} time
 * @returns {string|undefined}
 */
function normalizeTbs(time) {
    if (!time || typeof time !== 'string') return undefined;
    const trimmed = time.trim().toLowerCase();
    if (!trimmed) return undefined;

    if (trimmed === 'day' || trimmed === 'd' || trimmed === '24h' || trimmed === 'today') return 'qdr:d';
    if (trimmed === 'week' || trimmed === 'w') return 'qdr:w';
    if (trimmed === 'month' || trimmed === 'm') return 'qdr:m';
    if (trimmed === 'year' || trimmed === 'y') return 'qdr:y';
    if (trimmed === 'hour' || trimmed === 'h') return 'qdr:h';
    if (trimmed.startsWith('qdr:')) return trimmed;

    return undefined;
}

/**
 * Queries Serper for Google web search results.
 *
 * @param {string} query
 * @param {string} apiKey
 * @param {{ gl?: string, hl?: string, tbs?: string, page?: number, signal?: AbortSignal }} [options]
 * @returns {Promise<object>} raw response from Serper
 */
async function serperWebSearch(query, apiKey, { gl = 'de', hl = 'de', tbs, page = 1, signal } = {}) {
    const headers = {
        'X-API-KEY': apiKey,
        'Content-Type': 'application/json',
    };

    const timeoutSignal = AbortSignal.timeout(SEARCH_TIMEOUT_MS);
    const combined = signal ? AbortSignal.any([signal, timeoutSignal]) : timeoutSignal;

    const payload = {
        q: query,
        gl,
        hl,
    };
    if (tbs) payload.tbs = tbs;
    if (page && page > 1) payload.page = page;

    let response;
    try {
        response = await fetch(SERPER_SEARCH_ENDPOINT, {
            method: 'POST',
            headers,
            body: JSON.stringify(payload),
            redirect: 'follow',
            signal: combined,
        });
    } catch (err) {
        throw new ToolError(`web_search: network failure contacting Serper (${query}): ${err.message}`);
    }

    if (!response.ok) {
        let detail = `${response.status} ${response.statusText}`;
        try {
            const body = await response.text();
            if (body) detail += ` - ${body.slice(0, 300)}`;
        } catch { /* body already consumed or unreadable */ }
        throw new ToolError(`web_search: Serper API error: ${detail}`);
    }

    return await response.json();
}

/**
 * Creates the web_search tool.
 * @param {{ googleAuthId: number }} ctx
 */
export function createWebSearchTool({ googleAuthId }) {
    return defineTool({
        name: 'web_search',
        description:
            'Search Google via Serper.dev. Use timePeriod "day" or "week" for news/recent events. Returns 10 results per page.',
        strict: false,
        parameters: {
            type: 'object',
            additionalProperties: false,
            required: ['query'],
            properties: {
                note: {
                    type: ['string', 'null'],
                    description: 'A note explaining what this search is doing (or null). This note will be displayed to the user while the search is executing.',
                },
                query: {
                    type: 'string',
                    description: 'Search query.',
                },
                timePeriod: {
                    type: ['string', 'null'],
                    enum: ['day', 'week', 'month', 'year', null],
                    description: 'Time filter: "day", "week", "month", or "year", or null.',
                },
                gl: {
                    type: ['string', 'null'],
                    description: 'Country code or null. Default "de".',
                },
                hl: {
                    type: ['string', 'null'],
                    description: 'Language code or null. Default "de".',
                },
                page: {
                    type: ['number', 'null'],
                    description: 'Result page number (10/page) or null. Default 1.',
                },
            },
        },
        invoke: async ({ query, timePeriod, tbs, gl = 'de', hl = 'de', page = 1, note } = {}, { signal } = {}) => {
            const term = typeof query === 'string' ? query.trim() : '';
            if (!term) {
                throw new ToolError('web_search requires a non-empty "query".');
            }

            const parsedPage = page != null ? Number(page) : 1;
            if (!Number.isInteger(parsedPage) || parsedPage < 1) {
                throw new ToolError(`"page" must be a positive integer (received ${page}).`);
            }

            const normalizedTbs = normalizeTbs(timePeriod || tbs);

            let apiKey = null;
            try {
                const setting = await dbCompanySetting.getByKey(googleAuthId, 'keys.serper', { maskWriteonly: false });
                apiKey = setting?.value?.trim() || null;
            } catch (err) {
                console.warn('web_search: failed to read company setting keys.serper:', err?.message || err);
            }
            if (!apiKey && process.env.SERPER_API_KEY) {
                apiKey = process.env.SERPER_API_KEY.trim();
            }

            if (!apiKey) {
                throw new ToolError(
                    'web_search is unavailable: Serper API key not configured (companysetting: keys.serper).'
                );
            }

            return await serperWebSearch(term, apiKey, {
                gl,
                hl,
                tbs: normalizedTbs,
                page: parsedPage,
                signal,
            });
        },
    });
}