import {
  Inject,
  Injectable,
  InternalServerErrorException,
  Logger,
  forwardRef,
} from '@nestjs/common'
import { DatabaseService } from '../database/database.service'
import { createDefaultUserState } from '../shared/catalog/default-user-state'
import type { MeResponse, UserState } from '../shared/types/user.types'
import { GoldLandProgressionService } from '../gold-land/services/progression.service'

@Injectable()
export class UsersService {
  private readonly logger = new Logger(UsersService.name)

  constructor(
    @Inject(DatabaseService) private readonly database: DatabaseService,
    @Inject(forwardRef(() => GoldLandProgressionService))
    private readonly goldLandProgression: GoldLandProgressionService,
  ) {}

  ensureUser(userId: string): UserState {
    return this.getUserState(userId)
  }

  getUserState(userId: string): UserState {
    const row = this.database
      .getDb()
      .prepare('SELECT state_json FROM users WHERE id = ?')
      .get(userId) as { state_json: string } | undefined

    if (row) {
      return this.parseStateJson(row.state_json, userId)
    }

    const state = createDefaultUserState(userId)
    this.database
      .getDb()
      .prepare('INSERT INTO users (id, state_json, updated_at) VALUES (?, ?, ?)')
      .run(userId, JSON.stringify(state), new Date().toISOString())
    return state
  }

  saveUserState(state: UserState): UserState {
    this.database
      .getDb()
      .prepare('UPDATE users SET state_json = ?, updated_at = ? WHERE id = ?')
      .run(JSON.stringify(state), new Date().toISOString(), state.id)
    return state
  }

  toMeResponse(state: UserState): MeResponse {
    return {
      user: {
        id: state.id,
        name: state.name,
        level: state.level,
        xp: state.xp,
        maxXp: state.maxXp,
        coins: state.coins,
        missionProgress: state.missionProgress,
        missionTarget: state.missionTarget,
      },
      wallet: {
        cash: state.cash,
        goldGrams: state.goldGrams,
      },
      progress: {
        completedChallenges: state.completedChallenges,
        completedLessons: state.completedLessons,
        completedGames: state.completedGames,
        claimedRewards: state.claimedRewards,
        ownedItems: state.ownedItems,
        mapLevels: state.mapLevels,
        totalStars: state.totalStars,
        maxStars: state.maxStars,
      },
      achievements: state.achievements,
      transactions: state.transactions,
      market: {
        selectedRange: state.marketSelectedRange,
      },
    }
  }

  getMe(userId: string): MeResponse {
    const state = this.goldLandProgression.syncUserProgressionState(userId)
    return this.toMeResponse(state)
  }

  updateProfile(userId: string, name: string): MeResponse {
    return this.database.transaction(() => {
      const state = this.getUserState(userId)
      state.name = name.trim()
      this.saveUserState(state)
      return this.toMeResponse(state)
    })
  }

  private parseStateJson(raw: string, userId: string): UserState {
    try {
      return JSON.parse(raw) as UserState
    } catch (error) {
      this.logger.error(`Invalid state_json for user ${userId}`, error)
      throw new InternalServerErrorException('داده کاربر نامعتبر است')
    }
  }
}