import { createHash } from 'crypto';
import { asNumber, asRecord } from '@sammo-ts/common';
import { createGamePostgresConnector } from '@sammo-ts/infra';

import type { TurnCalendarHandler } from './inMemoryWorld.js';
import type { InMemoryTurnWorld } from './inMemoryWorld.js';

const MAP_VERSION = 0 as const;

type MapCityCompact = [number, number, number, number, number, number];
type MapNationCompact = [number, string, string, number];

type YearbookMap = {
    result: true;
    version: number;
    startYear: number;
    year: number;
    month: number;
    cityList: MapCityCompact[];
    nationList: MapNationCompact[];
};

type YearbookNation = {
    id: number;
    name: string;
    color: string;
    level: number;
    power: number;
    cities: string[];
};

const readState = (meta: Record<string, unknown>): number => {
    const raw = meta.state;
    if (typeof raw === 'number' && Number.isFinite(raw)) {
        return Math.floor(raw);
    }
    return 0;
};

const resolveStartYear = (meta: Record<string, unknown>): number => {
    const scenarioMeta = asRecord(meta.scenarioMeta);
    const startYear = scenarioMeta.startYear;
    if (typeof startYear === 'number' && Number.isFinite(startYear)) {
        return startYear;
    }
    return 0;
};

const buildMapSnapshot = (world: InMemoryTurnWorld, year: number, month: number): YearbookMap => {
    const state = world.getState();
    const cityList: MapCityCompact[] = world.listCities().map((city) => {
        const meta = asRecord(city.meta);
        const stateValue = city.state ?? readState(meta);
        const region = asNumber(meta.region, 0);
        const supplyFlag = city.supplyState > 0 ? 1 : 0;
        return [city.id, city.level, stateValue, city.nationId, region, supplyFlag];
    });

    const nationList: MapNationCompact[] = world
        .listNations()
        .map((nation) => [nation.id, nation.name, nation.color, nation.capitalCityId ?? 0]);

    return {
        result: true,
        version: MAP_VERSION,
        startYear: resolveStartYear(asRecord(state.meta)),
        year,
        month,
        cityList,
        nationList,
    };
};

const buildNationSnapshot = (world: InMemoryTurnWorld): YearbookNation[] => {
    const cities = world.listCities();
    const generals = world.listGenerals();
    const nations = world.listNations();

    const cityStatsByNation = new Map<number, { popSum: number; valueSum: number; maxSum: number }>();
    const cityNamesByNation = new Map<number, string[]>();

    for (const city of cities) {
        const entry = cityStatsByNation.get(city.nationId) ?? { popSum: 0, valueSum: 0, maxSum: 0 };
        const valueSum = city.population + city.agriculture + city.commerce + city.security + city.wall + city.defence;
        const maxSum =
            city.populationMax +
            city.agricultureMax +
            city.commerceMax +
            city.securityMax +
            city.wallMax +
            city.defenceMax;
        entry.popSum += city.population;
        entry.valueSum += valueSum;
        entry.maxSum += maxSum;
        cityStatsByNation.set(city.nationId, entry);

        const cityNames = cityNamesByNation.get(city.nationId) ?? [];
        cityNames.push(city.name);
        cityNamesByNation.set(city.nationId, cityNames);
    }

    const generalStatsByNation = new Map<number, { goldRice: number; statPower: number; expDed: number }>();
    for (const general of generals) {
        const entry = generalStatsByNation.get(general.nationId) ?? { goldRice: 0, statPower: 0, expDed: 0 };
        entry.goldRice += general.gold + general.rice;
        const leadership = general.stats.leadership;
        const strength = general.stats.strength;
        const intel = general.stats.intelligence;
        const npcMultiplier = general.npcState < 2 ? 1.2 : 1;
        const leaderCore = leadership >= 40 ? leadership : 0;
        entry.statPower += npcMultiplier * leaderCore * 2 + (Math.sqrt(intel * strength) * 2 + leadership / 2) / 2;
        entry.expDed += general.experience + general.dedication;
        generalStatsByNation.set(general.nationId, entry);
    }

    return nations.map((nation) => {
        const generalStats = generalStatsByNation.get(nation.id) ?? { goldRice: 0, statPower: 0, expDed: 0 };
        const cityStats = cityStatsByNation.get(nation.id) ?? { popSum: 0, valueSum: 0, maxSum: 0 };
        const resource = Math.round(((nation.gold ?? 0) + (nation.rice ?? 0) + generalStats.goldRice) / 100);
        const tech = asNumber(asRecord(nation.meta).tech, 0);
        const cityPower =
            nation.level > 0 && cityStats.maxSum > 0
                ? Math.round((cityStats.popSum * cityStats.valueSum) / cityStats.maxSum / 100)
                : 0;
        const expDed = Math.round(generalStats.expDed / 100);
        const power = Math.round((resource + tech + cityPower + generalStats.statPower + expDed) / 10);

        return {
            id: nation.id,
            name: nation.name,
            color: nation.color,
            level: nation.level,
            power,
            cities: cityNamesByNation.get(nation.id) ?? [],
        };
    });
};

const buildHash = (map: YearbookMap, nations: YearbookNation[]): string =>
    createHash('sha256').update(JSON.stringify({ map, nations })).digest('hex');

export const createYearbookHandler = (options: {
    databaseUrl: string;
    profileName: string;
    getWorld: () => InMemoryTurnWorld | null;
}): { handler: TurnCalendarHandler; close: () => Promise<void> } => {
    const connector = createGamePostgresConnector({ url: options.databaseUrl });
    const ready = connector.connect();

    const handler: TurnCalendarHandler = {
        beforeMonthChanged: async (context) => {
            const world = options.getWorld();
            if (!world) {
                return;
            }
            await ready;
            const map = buildMapSnapshot(world, context.previousYear, context.previousMonth);
            const nations = buildNationSnapshot(world);
            const hash = buildHash(map, nations);

            await connector.prisma.yearbookHistory.upsert({
                where: {
                    profileName_year_month: {
                        profileName: options.profileName,
                        year: context.previousYear,
                        month: context.previousMonth,
                    },
                },
                update: {
                    map,
                    nations,
                    hash,
                },
                create: {
                    profileName: options.profileName,
                    year: context.previousYear,
                    month: context.previousMonth,
                    map,
                    nations,
                    hash,
                },
            });
        },
    };

    const close = async () => {
        await connector.disconnect();
    };

    return { handler, close };
};