import {apiFetch} from './api.js';
import {parseStatus} from './backlog.js';
import {MAX_IMPORT_TITLE_LENGTH, MAX_PLATFORM_LENGTH, MAX_PLAYTIME_MINUTES} from './limits.js';
import {hoursToMinutes, toHours} from './manualGames.js';
import {preselectPlatform} from './platforms.js';

const IMPORTS_URL = () => `${import.meta.env.VITE_CORE_API_URL}/api/library/imports`;
const JSON_HEADERS = {'Content-Type': 'application/json'};

// The calls return the raw response; the caller handles the status.
export const createImport = (source, rows) =>
    apiFetch(IMPORTS_URL(), {method: 'POST', headers: JSON_HEADERS, body: JSON.stringify({source, rows})});

export const listImports = () => apiFetch(IMPORTS_URL());

export const getImport = (id) => apiFetch(`${IMPORTS_URL()}/${id}`);

// shownLineNos: the lines the user saw; a PlayStation review keeps the others open (the sync may add lines meanwhile).
export const saveImport = (id, rows, shownLineNos) =>
    apiFetch(`${IMPORTS_URL()}/${id}/save`, {method: 'POST', headers: JSON_HEADERS, body: JSON.stringify({rows, shownLineNos})});

export const retryImport = (id) => apiFetch(`${IMPORTS_URL()}/${id}/retry`, {method: 'POST'});

export const checkUndo = (id) => apiFetch(`${IMPORTS_URL()}/${id}/undo-check`);

export const undoImport = (id) => apiFetch(`${IMPORTS_URL()}/${id}/games`, {method: 'DELETE'});

/**
 * One title per line; empty lines are left out.
 */
export const parseTextList = (text) => text.split(/\r?\n/).map((line) => line.trim()).filter(Boolean)
    .map((line) => ({title: line.slice(0, MAX_IMPORT_TITLE_LENGTH)}));

// Header names, lower case, per field.
const COLUMNS = {
    title: ['title', 'name', 'game'],
    platform: ['platform'],
    hours: ['hours', 'playtime', 'playtime (hours)'],
    minutes: ['minutes', 'playtime (minutes)'],
    status: ['status'],
};

/**
 * A CSV with a header row; the delimiter (comma, semicolon or tab) is the one the header has most of. A field that
 * starts with a double quote may hold the delimiter, line breaks and "" for a quote.
 *
 * @return {rows} with title, platform, playtimeMinutes and status where the file has them, or {error} as an i18n key
 */
export const parseCsv = (text) => csvRows(readCsv(text));

export const csvRows = ({names, records}) => {
    const at = Object.fromEntries(Object.entries(COLUMNS)
        .map(([field, headers]) => [field, names.findIndex((name) => headers.includes(name))]));
    if (at.title < 0) return {error: 'IMPORT.CSV_NO_TITLE'};

    const value = (record, field) => (at[field] >= 0 ? (record[at[field]] ?? '').trim() : '');
    const rows = records.filter((record) => value(record, 'title')).map((record) => importRow({
        title: value(record, 'title'),
        platform: value(record, 'platform'),
        minutes: at.minutes >= 0 ? Number(value(record, 'minutes')) : hoursToMinutes(value(record, 'hours')),
        status: parseStatus(value(record, 'status').toUpperCase()),
    }));
    return {rows};
};

/**
 * A row as Core takes it: within the limits, and null for what is unknown.
 */
export const importRow = ({title, platform, minutes, status}) => {
    const playtime = Math.round(minutes);
    return {
        title: title.trim().slice(0, MAX_IMPORT_TITLE_LENGTH),
        platform: typeof platform === 'string' && platform && platform.length <= MAX_PLATFORM_LENGTH ? platform : null,
        playtimeMinutes: playtime > 0 ? Math.min(playtime, MAX_PLAYTIME_MINUTES) : null,
        status: status ?? null,
    };
};

/**
 * @return {names, records}: the header names in lower case and the other records as arrays of fields
 */
export const readCsv = (text) => {
    const clean = text.replace(/^\uFEFF/, '');
    const firstLine = clean.split(/\r?\n/, 1)[0];
    const delimiter = [',', ';', '\t'].reduce((best, next) =>
        firstLine.split(next).length > firstLine.split(best).length ? next : best);
    const [header, ...records] = csvRecords(clean, delimiter);
    return {names: (header ?? []).map((name) => name.trim().toLowerCase()), records};
};

function csvRecords(text, delimiter) {
    const records = [];
    let record = [];
    let field = '';
    let quoted = false;
    for (let i = 0; i < text.length; i++) {
        const c = text[i];
        if (quoted) {
            if (c === '"' && text[i + 1] === '"') {
                field += '"';
                i++;
            } else if (c === '"') {
                quoted = false;
            } else {
                field += c;
            }
        } else if (c === '"' && field === '') {
            // Only at the start of a field; a quote inside one (12" Barbarian) is a character.
            quoted = true;
        } else if (c === delimiter) {
            record.push(field);
            field = '';
        } else if (c === '\n' || c === '\r') {
            if (c === '\r' && text[i + 1] === '\n') i++;
            record.push(field);
            records.push(record);
            record = [];
            field = '';
        } else {
            field += c;
        }
    }
    if (field || record.length) {
        record.push(field);
        records.push(record);
    }
    return records;
}

// Statuses a worker still has: the page polls while it shows one.
export const RUNNING = ['QUEUED', 'MATCHING', 'SAVING'];
// The steps an import goes through, as shown to the user.
export const STEPS = ['QUEUED', 'MATCHING', 'REVIEW', 'SAVING', 'DETAILS', 'DONE'];

/**
 * The step an import is in; a FAILED one is in the step it stopped in.
 */
export const stepOf = (data) => {
    switch (data.status) {
        case 'QUEUED': return 'QUEUED';
        case 'MATCHING': return 'MATCHING';
        case 'READY': return 'REVIEW';
        case 'SAVING': return data.step === 'DETAILS' ? 'DETAILS' : 'SAVING';
        case 'FAILED': return data.chosen > 0 ? 'SAVING' : 'MATCHING';
        default: return 'DONE';
    }
};

/**
 * The first choice of a line: its best candidate with the preselected platform; checked only for a sure match (the
 * same name, not in the library yet, a platform found).
 */
export const initialChoice = (row, favorite) => {
    const candidate = row.candidates[0];
    const platform = candidate ? preselectPlatform(row.platform, candidate.platforms, favorite) : '';
    return {
        candidates: row.candidates,
        igdbId: candidate?.igdbId ?? null,
        platform,
        status: row.status ?? 'BACKLOG',
        hours: toHours(row.playtimeMinutes),
        checked: row.exact && !!candidate && !candidate.inLibrary && platform !== '',
    };
};