/**
 * AllianceWarSystem — GDD Phase 3 Launch Prep
 *
 * 72-hour scheduled alliance wars. Alliances declare war on each other.
 * War score = fleet battles won. Territory bonuses for winning alliance.
 * Each war cycles through: declaration (24h) → active (72h) → resolution.
 */

const mongoose = require('mongoose');

const warSchema = new mongoose.Schema({
  warId:          { type: String, required: true, unique: true },
  attackerId:     { type: String, required: true },
  attackerName:   { type: String, required: true },
  attackerTag:    { type: String, required: true },
  defenderId:     { type: String, required: true },
  defenderName:   { type: String, required: true },
  defenderTag:    { type: String, required: true },
  status:         { type: String, default: 'declaration', enum: ['declaration','active','ended'] },
  attackerScore:  { type: Number, default: 0 },
  defenderScore:  { type: Number, default: 0 },
  battles:        [{ type: mongoose.Schema.Types.Mixed }],
  declaredAt:     { type: Date, default: Date.now },
  startedAt:      { type: Date, default: null },
  endsAt:         { type: Date, default: null },
  winnerId:       { type: String, default: null },
  winnerName:     { type: String, default: null },
  territory:      { type: mongoose.Schema.Types.Mixed, default: null },
}, { timestamps: true });

let AllianceWar;
try { AllianceWar = mongoose.model('AllianceWar'); }
catch(e) { AllianceWar = mongoose.model('AllianceWar', warSchema); }

class AllianceWarSystem {
  constructor() {
    this.io = null;
    // Territory bonus applied to winning alliance members for 7 days
    this.TERRITORY_BONUSES = {
      resource_production: 0.10, // +10% all resource production
      market_fee_reduction: 0.005, // −0.5% market fee
      xp_bonus: 0.05,             // +5% XP gain
    };
    this.DECLARATION_HOURS = 24;
    this.WAR_HOURS         = 72;
  }

  setIO(io) { this.io = io; }

  // ── Declare War ───────────────────────────────────────────────────
  async declareWar(attackerAlliance, defenderAlliance) {
    if (!attackerAlliance || !defenderAlliance) throw new Error('Invalid alliances');
    if (attackerAlliance._id.toString() === defenderAlliance._id.toString()) {
      throw new Error('Cannot declare war on your own alliance');
    }

    // Check no existing active war between these two
    const existing = await AllianceWar.findOne({
      status: { $in: ['declaration','active'] },
      $or: [
        { attackerId: attackerAlliance._id.toString(), defenderId: defenderAlliance._id.toString() },
        { attackerId: defenderAlliance._id.toString(), defenderId: attackerAlliance._id.toString() },
      ]
    });
    if (existing) throw new Error('A war between these alliances is already in progress');

    const warId    = `war_${Date.now()}_${Math.random().toString(36).substr(2, 6)}`;
    const declaredAt = new Date();
    const startedAt  = new Date(declaredAt.getTime() + this.DECLARATION_HOURS * 3600 * 1000);
    const endsAt     = new Date(startedAt.getTime() + this.WAR_HOURS * 3600 * 1000);

    const war = await AllianceWar.create({
      warId,
      attackerId:   attackerAlliance._id.toString(),
      attackerName: attackerAlliance.name,
      attackerTag:  attackerAlliance.tag,
      defenderId:   defenderAlliance._id.toString(),
      defenderName: defenderAlliance.name,
      defenderTag:  defenderAlliance.tag,
      status:       'declaration',
      declaredAt, startedAt, endsAt,
    });

    // Schedule auto-start and auto-end
    const toStart = startedAt.getTime() - Date.now();
    const toEnd   = endsAt.getTime() - Date.now();
    if (toStart > 0) setTimeout(() => this._activateWar(warId), toStart);
    if (toEnd   > 0) setTimeout(() => this._resolveWar(warId), toEnd);

    return war;
  }

  async _activateWar(warId) {
    const war = await AllianceWar.findOne({ warId });
    if (!war || war.status !== 'declaration') return;
    war.status = 'active';
    await war.save();
    if (this.io) this.io.emit('alliance_war_started', { warId, attackerTag: war.attackerTag, defenderTag: war.defenderTag });
  }

  async _resolveWar(warId) {
    const war = await AllianceWar.findOne({ warId });
    if (!war || war.status === 'ended') return;
    war.status = 'ended';

    if (war.attackerScore > war.defenderScore) {
      war.winnerId   = war.attackerId;
      war.winnerName = war.attackerName;
    } else if (war.defenderScore > war.attackerScore) {
      war.winnerId   = war.defenderId;
      war.winnerName = war.defenderName;
    } else {
      war.winnerName = 'Draw';
    }

    // Territory bonus for winning alliance (stored as metadata on war doc)
    if (war.winnerId) {
      war.territory = {
        allianceId: war.winnerId,
        bonuses:    this.TERRITORY_BONUSES,
        expiresAt:  new Date(Date.now() + 7 * 24 * 3600 * 1000),
      };
    }

    await war.save();
    if (this.io) {
      this.io.emit('alliance_war_ended', {
        warId,
        attackerTag:    war.attackerTag,  attackerScore: war.attackerScore,
        defenderTag:    war.defenderTag,  defenderScore: war.defenderScore,
        winnerName:     war.winnerName,
        territoryBonus: war.territory ? this.TERRITORY_BONUSES : null,
      });
    }
  }

  // ── Battle Submission ──────────────────────────────────────────────
  async submitBattle(warId, attackerUserId, defenderUserId, attackerWon, battleDetails = {}) {
    const war = await AllianceWar.findOne({ warId, status: 'active' });
    if (!war) throw new Error('War not found or not active');

    const battle = {
      attackerUserId, defenderUserId, attackerWon,
      at: new Date(), ...battleDetails,
    };
    war.battles.push(battle);

    // Score: 1 point per win for the winning side
    if (attackerWon) war.attackerScore += 1;
    else             war.defenderScore += 1;

    await war.save();

    if (this.io) {
      this.io.emit('alliance_war_battle', {
        warId,
        attackerTag: war.attackerTag, attackerScore: war.attackerScore,
        defenderTag: war.defenderTag, defenderScore: war.defenderScore,
        battle,
      });
    }
    return war;
  }

  // ── Queries ────────────────────────────────────────────────────────
  async getActiveWars() {
    return AllianceWar.find({ status: { $in: ['declaration','active'] } }).sort({ declaredAt: -1 }).limit(20);
  }

  async getWarsByAlliance(allianceId) {
    return AllianceWar.find({
      $or: [{ attackerId: allianceId }, { defenderId: allianceId }]
    }).sort({ declaredAt: -1 }).limit(10);
  }

  async getWar(warId) {
    return AllianceWar.findOne({ warId });
  }

  async getTerritoryBonus(allianceId) {
    const now = new Date();
    const war = await AllianceWar.findOne({
      status: 'ended',
      winnerId: allianceId,
      'territory.expiresAt': { $gt: now },
    });
    return war ? war.territory.bonuses : null;
  }

  // Resume timers on server restart
  async resumeTimers() {
    const wars = await AllianceWar.find({ status: { $in: ['declaration','active'] } });
    const now  = Date.now();
    for (const war of wars) {
      if (war.status === 'declaration' && war.startedAt > new Date()) {
        const ms = war.startedAt.getTime() - now;
        if (ms > 0) setTimeout(() => this._activateWar(war.warId), ms);
      }
      if (war.endsAt > new Date()) {
        const ms = war.endsAt.getTime() - now;
        if (ms > 0) setTimeout(() => this._resolveWar(war.warId), ms);
      }
    }
  }
}

module.exports = AllianceWarSystem;