// SPDX-FileCopyrightText: 2022 Johannes Loher
//
// SPDX-License-Identifier: MIT

import { packageId } from '../../constants';
import { getGame } from '../../helpers';

import type { TickwerkCombatant } from './combatant';

export const registerCombatFunctionality = () => {
  CONFIG.Combat.documentClass = CombatMixin(CONFIG.Combat.documentClass);
};

const CombatMixin = (BaseCombat: typeof Combat) => {
  return class TickwerkCombat extends BaseCombat {
    override get combatant() {
      return this.turns[0];
    }

    override get round() {
      return this.tickValue;
    }

    override get started() {
      return this.turns.length > 0 && (this.getFlag(packageId, 'started') ?? false);
    }

    override get turn() {
      return 0;
    }

    /**
     * The current tick value of the Combat encounter.
     */
    get tickValue(): number {
      const tickValues = this.combatants
        .filter((combatant) => !combatant.isDefeated)
        .map((combatant) => combatant.initiative)
        .filter((tickValue): tickValue is number => tickValue !== null);
      const tickValue = Math.min(...tickValues);
      return tickValue === Infinity ? 0 : tickValue;
    }

    override async nextRound(): Promise<never> {
      throw new Error('Not implemented!');
    }

    override async nextTurn() {
      const game = getGame();

      const combatant = this.combatant;
      if (combatant === undefined || combatant.id === null) {
        return this;
      }

      const ticks = await Dialog.prompt({
        title: game.i18n.localize('TICKWERK.AdvanceTicks'),
        content: '<input name="ticks" type="number" value="5" min="0" />',
        label: game.i18n.localize('TICKWERK.AdvanceTicks'),
        callback: (html) => {
          const ticks = html[0]?.querySelector<HTMLInputElement>('input[name="ticks"]')?.value;
          return ticks !== undefined ? parseInt(ticks) : undefined;
        },
        rejectClose: false,
      });

      if (ticks !== undefined && ticks !== null) {
        await combatant.advanceTicks(ticks);
      }

      return this;
    }

    override previousRound(): Promise<never> {
      throw new Error('Not implemented!');
    }

    override previousTurn(): Promise<never> {
      throw new Error('Not implemented!');
    }

    override async resetAll() {
      for (const c of this.combatants) {
        c.data.update({ initiative: null });
      }
      return this.update(
        {
          turn: 0,
          combatants: this.combatants.toObject().map((combatant) => {
            if (combatant.flags.tickwerk.tiebreaker) delete combatant.flags.tickwerk.tiebreaker;
            return { ...combatant, [`flags.${packageId}.-=tiebreaker`]: null };
          }),
          flags: { [packageId]: { started: false } },
        },
        { diff: false },
      );
    }

    override setupTurns(): this['turns'] {
      const turns = this.combatants.contents.sort(this._sortCombatants);

      const c = turns[0];
      this.current = {
        round: this.round,
        turn: 0,
        combatantId: c?.id ?? null,
        tokenId: c?.data.tokenId ?? null,
      };
      return (this.turns = turns);
    }

    override async startCombat(): Promise<this | undefined> {
      const hasCombatantWithTickValue = this.combatants.find(
        (combatant) => !combatant.isDefeated && combatant.initiative !== null,
      );
      if (!hasCombatantWithTickValue) {
        ui.notifications?.warn('TICKWERK.WarningCannotStartCombat', { localize: true });
        return this;
      }
      return this.setFlag(packageId, 'started', true);
    }

    protected override _sortCombatants(a: TickwerkCombatant, b: TickwerkCombatant): number {
      const da = a.isDefeated ? 1 : 0;
      const db = b.isDefeated ? 1 : 0;
      const cd = da - db;
      if (cd !== 0) return cd;

      const wa = a.waiting ? 1 : 0;
      const wb = b.waiting ? 1 : 0;
      const cw = wa - wb;
      if (cw !== 0) return cw;

      const ia = a.initiative ?? Infinity;
      const ib = b.initiative ?? Infinity;
      const ci = ia - ib;
      if (ci !== 0) return ci;

      const tba = a.getFlag(packageId, 'tiebreaker') ?? 0;
      const tbb = b.getFlag(packageId, 'tiebreaker') ?? 0;
      const ctb = tba - tbb;
      if (ctb !== 0) return ctb;

      return (b.id ?? '') > (a.id ?? '') ? 1 : -1;
    }
  };
};

declare global {
  interface FlagConfig {
    Combat: {
      tickwerk?: {
        started?: boolean;
      };
    };
  }
}