@jeremyckahn/farmhand/src/game-logic/reducers/processLevelUp.ts

A farming game

import { levels } from '../../data/levels.js'
import { levelAchieved } from '../../utils/levelAchieved.js'
import {
  getRandomLevelUpReward,
  getRandomLevelUpRewardQuantity,
} from '../../utils/index.js'
import { getLevelEntitlements } from '../../utils/getLevelEntitlements.js'
import { SPRINKLER_ITEM_ID } from '../../constants.js'
import { LEVEL_GAINED_NOTIFICATION } from '../../templates.js'

import { addItemToInventory } from './addItemToInventory.js'
import { showNotification } from './showNotification.js'
import { unlockTool } from './unlockTool.js'

/**
 * @param {farmhand.state} state
 * @param {number} oldLevel
 * @returns {farmhand.state}
 */
export const processLevelUp = (state, oldLevel) => {
  const { experience, selectedItemId } = state
  const newLevel = levelAchieved(experience)

  // Loop backwards so that the notifications appear in descending order.
  for (let i = newLevel; i > oldLevel; i--) {
    const levelObject = (levels[i] || {}) as {
      unlocksTool?: farmhand.toolType
      increasesSprinklerRange?: boolean
    }

    let randomCropSeed
    // There is no predefined reward for this level up.
    if (Object.keys(levelObject).length < 2) {
      randomCropSeed = getRandomLevelUpReward(i)
      state = addItemToInventory(
        state,
        randomCropSeed,
        getRandomLevelUpRewardQuantity(i),
        true
      )
    } else if (levelObject?.unlocksTool) {
      state = unlockTool(state, levelObject.unlocksTool)
    }
    // This handles an edge case where the player levels up to level that
    // unlocks greater sprinkler range, but the sprinkler item is already
    // selected. In that case, update the hoveredPlotRangeSize state.
    else if (
      levelObject &&
      levelObject.increasesSprinklerRange &&
      selectedItemId === SPRINKLER_ITEM_ID
    ) {
      const { sprinklerRange } = getLevelEntitlements(levelAchieved(experience))

      if (sprinklerRange > state.hoveredPlotRangeSize) {
        state = {
          ...state,
          hoveredPlotRangeSize: sprinklerRange,
        }
      }
    }

    state = showNotification(
      state,
      LEVEL_GAINED_NOTIFICATION('', i, randomCropSeed),
      'success'
    )
  }

  return state
}