import type { IComposeConfigProvider } from '../config/IComposeConfigProvider';
import { PlaceRejectReason, type BagSlotRecord } from '../types/MergeTypes';

/** 背包内单格 Weapon1 合成升级 */
export class UpgradeSystem {
    constructor(private readonly _config: IComposeConfigProvider) {}

    canMergeInBag(source: BagSlotRecord, target: BagSlotRecord): PlaceRejectReason | null {
        const srcType = this._config.getWeapon2Type(source.weapon2Id);
        const dstType = this._config.getWeapon2Type(target.weapon2Id);
        if (srcType !== 1 || dstType !== 1) {
            return PlaceRejectReason.InvalidMerge;
        }

        const srcW1 = source.weapon1Id ?? this._config.getWeapon1ByGroupSequence([source.weapon2Id]);
        const dstW1 = target.weapon1Id ?? this._config.getWeapon1ByGroupSequence([target.weapon2Id]);
        if (srcW1 == null || dstW1 == null) {
            return PlaceRejectReason.InvalidMerge;
        }
        if (!this._config.isSingleCellWeapon1(srcW1)) {
            return PlaceRejectReason.InvalidMerge;
        }

        const srcLevel = source.level ?? 1;
        const dstLevel = target.level ?? 1;
        if (srcW1 !== dstW1 || srcLevel !== dstLevel) {
            return PlaceRejectReason.InvalidMerge;
        }

        const max = this._config.getMaxWeaponLevel(srcW1);
        if (srcLevel >= max) {
            return PlaceRejectReason.MaxLevel;
        }
        return null;
    }

    mergeInBag(target: BagSlotRecord): BagSlotRecord {
        const w1 = target.weapon1Id ?? this._config.getWeapon1ByGroupSequence([target.weapon2Id]);
        const next = (target.level ?? 1) + 1;
        if (w1 == null) {
            console.log('[UpgradeSystem] mergeInBag 无法解析 Weapon1');
            return { ...target };
        }
        return {
            ...target,
            level: Math.min(this._config.getMaxWeaponLevel(w1), next),
        };
    }

    /** 多字 Weapon1：拖字块到已组合单位上升级 */
    canUpgradeOnMap(
        bagTile: BagSlotRecord,
        composedWeapon1Id: number,
        composedLevel: number,
        requiredWeapon2Id: number,
    ): PlaceRejectReason | null {
        if (bagTile.weapon2Id !== requiredWeapon2Id) {
            return PlaceRejectReason.InvalidMerge;
        }
        const max = this._config.getMaxWeaponLevel(composedWeapon1Id);
        if (composedLevel >= max) {
            return PlaceRejectReason.MaxLevel;
        }
        return null;
    }

    upgradeLevel(level: number): number {
        return level + 1;
    }
}