// ─── Study Slice ─────────────────────────────────────────────────────────────
// Actions for studying skills and spells

import type { GameState } from './types';
import { SKILLS_DEF, SPELLS_DEF, getStudyCostMultiplier } from './constants';

// ─── Study Actions Interface ──────────────────────────────────────────────────

export interface StudyActions {
  startStudyingSkill: (skillId: string) => void;
  startStudyingSpell: (spellId: string) => void;
  cancelStudy: () => void;
  startParallelStudySkill: (skillId: string) => void;
  cancelParallelStudy: () => void;
}

// ─── Study Slice Factory ──────────────────────────────────────────────────────

export function createStudySlice(
  set: (partial: Partial<GameState> | ((state: GameState) => Partial<GameState>)) => void,
  get: () => GameState
): StudyActions {
  return {
    // Start studying a skill - mana is deducted per hour, not upfront
    startStudyingSkill: (skillId: string) => {
      const state = get();
      const sk = SKILLS_DEF[skillId];
      if (!sk) return;

      const currentLevel = state.skills[skillId] || 0;
      if (currentLevel >= sk.max) return;

      // Check prerequisites
      if (sk.req) {
        for (const [r, rl] of Object.entries(sk.req)) {
          if ((state.skills[r] || 0) < rl) return;
        }
      }

      // Calculate total mana cost and cost per hour
      const costMult = getStudyCostMultiplier(state.skills);
      const totalCost = Math.floor(sk.base * (currentLevel + 1) * costMult);
      const manaCostPerHour = Math.ceil(totalCost / sk.studyTime);
      
      // Must have at least 1 hour worth of mana to start
      if (state.rawMana < manaCostPerHour) return;

      // Start studying (no upfront cost - mana is deducted per hour during study)
      set({
        currentAction: 'study',
        currentStudyTarget: {
          type: 'skill',
          id: skillId,
          progress: state.skillProgress[skillId] || 0,
          required: sk.studyTime,
          manaCostPerHour: manaCostPerHour,
          totalCost: totalCost,
        },
        log: [`📚 Started studying ${sk.name} (${manaCostPerHour} mana/hr)...`, ...state.log.slice(0, 49)],
      });
    },

    // Start studying a spell
    startStudyingSpell: (spellId: string) => {
      const state = get();
      const sp = SPELLS_DEF[spellId];
      if (!sp || state.spells[spellId]?.learned) return;

      // Calculate total mana cost and cost per hour
      const costMult = getStudyCostMultiplier(state.skills);
      const totalCost = Math.floor(sp.unlock * costMult);
      const studyTime = sp.studyTime || (sp.tier * 4);
      const manaCostPerHour = Math.ceil(totalCost / studyTime);
      
      // Must have at least 1 hour worth of mana to start
      if (state.rawMana < manaCostPerHour) return;

      // Start studying (no upfront cost - mana is deducted per hour during study)
      set({
        currentAction: 'study',
        currentStudyTarget: {
          type: 'spell',
          id: spellId,
          progress: state.spells[spellId]?.studyProgress || 0,
          required: studyTime,
          manaCostPerHour: manaCostPerHour,
          totalCost: totalCost,
        },
        spells: {
          ...state.spells,
          [spellId]: { ...(state.spells[spellId] || { learned: false, level: 0 }), studyProgress: state.spells[spellId]?.studyProgress || 0 },
        },
        log: [`📚 Started studying ${sp.name} (${manaCostPerHour} mana/hr)...`, ...state.log.slice(0, 49)],
      });
    },

    // Cancel current study (saves progress)
    cancelStudy: () => {
      const state = get();
      if (!state.currentStudyTarget) return;

      // Knowledge retention bonus
      const retentionBonus = 1 + (state.skills.knowledgeRetention || 0) * 0.2;
      const savedProgress = Math.min(
        state.currentStudyTarget.progress,
        state.currentStudyTarget.required * retentionBonus
      );

      // Save progress
      if (state.currentStudyTarget.type === 'skill') {
        set({
          currentStudyTarget: null,
          currentAction: 'meditate',
          skillProgress: {
            ...state.skillProgress,
            [state.currentStudyTarget.id]: savedProgress,
          },
          log: [`📖 Study interrupted. Progress saved.`, ...state.log.slice(0, 49)],
        });
      } else if (state.currentStudyTarget.type === 'spell') {
        set({
          currentStudyTarget: null,
          currentAction: 'meditate',
          spells: {
            ...state.spells,
            [state.currentStudyTarget.id]: {
              ...(state.spells[state.currentStudyTarget.id] || { learned: false, level: 0 }),
              studyProgress: savedProgress,
            },
          },
          log: [`📖 Study interrupted. Progress saved.`, ...state.log.slice(0, 49)],
        });
      }
    },

    // Start parallel study of a skill (requires Parallel Mind upgrade)
    startParallelStudySkill: (skillId: string) => {
      const state = get();
      if (state.parallelStudyTarget) return; // Already have parallel study
      if (!state.currentStudyTarget) return; // Need primary study

      const sk = SKILLS_DEF[skillId];
      if (!sk) return;

      const currentLevel = state.skills[skillId] || 0;
      if (currentLevel >= sk.max) return;

      // Can't study same thing in parallel
      if (state.currentStudyTarget.id === skillId) return;

      // Calculate mana cost for parallel study
      const costMult = getStudyCostMultiplier(state.skills);
      const totalCost = Math.floor(sk.base * (currentLevel + 1) * costMult);
      const manaCostPerHour = Math.ceil(totalCost / sk.studyTime);

      set({
        parallelStudyTarget: {
          type: 'skill',
          id: skillId,
          progress: state.skillProgress[skillId] || 0,
          required: sk.studyTime,
          manaCostPerHour: Math.ceil(manaCostPerHour / 2), // Half speed = half mana cost per tick
          totalCost: totalCost,
        },
        log: [`📚 Started parallel study of ${sk.name}... (50% speed)`, ...state.log.slice(0, 49)],
      });
    },

    // Cancel parallel study
    cancelParallelStudy: () => {
      set((state) => {
        if (!state.parallelStudyTarget) return state;
        return {
          parallelStudyTarget: null,
          log: ['📖 Parallel study cancelled.', ...state.log.slice(0, 49)],
        };
      });
    },
  };
}