import { Injectable } from '@nestjs/common'
import { InjectModel } from '@nestjs/mongoose'
import { Model } from 'mongoose'
import { SiteConfig, SiteConfigDocument } from './site-config.schema'

export interface GravityRates {
  interviewPerUse: number    // 每次面试消耗引力值
  optimizePerUse: number     // 每次优化消耗引力值
  downloadPerUse: number     // 每次下载消耗引力值
}

interface PricingConfig {
  /** 新用户注册赠送引力值 */
  registrationGravity: number
  interview: { pricePerSession: number; creditsPerPurchase: number }
  resumeOptimize: { freeLimit: number; pricePerOptimize: number; creditsPerPurchase: number }
  resumeDownload: { pricePerDownload: number; creditsPerPurchase: number }
  gravityRates: GravityRates
  plans: {
    growth: { price: number; durationDays: number; gravityPerMonth: number; credits: { interview: number; resumeOptimize: number; resumeDownload: number }; features: string[] }
    sprint: { price: number; durationDays: number; gravityPerMonth: number; credits: { interview: number; resumeOptimize: number; resumeDownload: number }; features: string[] }
  }
}

const DEFAULT_PRICING: PricingConfig = {
  registrationGravity: 50,
  interview: { pricePerSession: 600, creditsPerPurchase: 1 },
  resumeOptimize: { freeLimit: 3, pricePerOptimize: 400, creditsPerPurchase: 1 },
  resumeDownload: { pricePerDownload: 200, creditsPerPurchase: 1 },
  gravityRates: { interviewPerUse: 5, optimizePerUse: 3, downloadPerUse: 2 },
  plans: {
    growth: { price: 1900, durationDays: 30, gravityPerMonth: 80, credits: { interview: 999, resumeOptimize: 20, resumeDownload: 10 }, features: ['免费版全部权益', 'AI 模拟面试（每次消耗 5 引力值，无限次）', '详细面试报告（四维评分 + 语音复盘）', '进步轨迹雷达图 + 打卡日历', '每日一题推送 + 参考思路', '公司真题库', '每月赠送 80 引力值，可用于面试/优化/下载'] },
    sprint: { price: 4900, durationDays: 30, gravityPerMonth: 200, credits: { interview: 999, resumeOptimize: 50, resumeDownload: 30 }, features: ['成长版全部权益', 'AI 语音深度分析（语气词/语速/停顿检测）', '技能缺口分析报告', '公司真题库精选', '每月赠送 200 引力值，可用于面试/优化/下载'] },
  },
}

@Injectable()
export class PricingService {
  private cache: PricingConfig | null = null
  private cacheTime = 0

  constructor(
    @InjectModel(SiteConfig.name) private configModel: Model<SiteConfigDocument>,
  ) {}

  async getConfig(): Promise<PricingConfig> {
    // Cache for 60s
    if (this.cache && Date.now() - this.cacheTime < 60000) {
      return this.cache
    }
    try {
      const doc = await this.configModel.findOne({ key: 'pricing' }).exec()
      if (doc?.value) {
        this.cache = this.mergeDefaults(doc.value)
        this.cacheTime = Date.now()
        return this.cache
      }
    } catch {}
    return DEFAULT_PRICING
  }

  invalidateCache() {
    this.cache = null
  }

  private mergeDefaults(value: any): PricingConfig {
    return {
      registrationGravity: value?.registrationGravity ?? DEFAULT_PRICING.registrationGravity,
      interview: { ...DEFAULT_PRICING.interview, ...value?.interview },
      resumeOptimize: { ...DEFAULT_PRICING.resumeOptimize, ...value?.resumeOptimize },
      resumeDownload: { ...DEFAULT_PRICING.resumeDownload, ...value?.resumeDownload },
      gravityRates: { ...DEFAULT_PRICING.gravityRates, ...value?.gravityRates },
      plans: {
        growth: { ...DEFAULT_PRICING.plans.growth, ...value?.plans?.growth, credits: { ...DEFAULT_PRICING.plans.growth.credits, ...value?.plans?.growth?.credits } },
        sprint: { ...DEFAULT_PRICING.plans.sprint, ...value?.plans?.sprint, credits: { ...DEFAULT_PRICING.plans.sprint.credits, ...value?.plans?.sprint?.credits } },
      },
    }
  }
}