import type {
  LeagueConfigFormModel,
} from '@gridpilot/racing/application';
import type {
  CreateLeagueWithSeasonAndScoringCommand,
  CreateLeagueWithSeasonAndScoringResultDTO,
} from '@gridpilot/racing/application/use-cases/CreateLeagueWithSeasonAndScoringUseCase';
import {
  getDriverRepository,
  getCreateLeagueWithSeasonAndScoringUseCase,
} from '@/lib/di-container';

export type WizardStep = 1 | 2 | 3 | 4 | 5;

export interface WizardErrors {
  basics?: {
    name?: string;
    visibility?: string;
  };
  structure?: {
    maxDrivers?: string;
    maxTeams?: string;
    driversPerTeam?: string;
  };
  timings?: {
    qualifyingMinutes?: string;
    mainRaceMinutes?: string;
    roundsPlanned?: string;
  };
  scoring?: {
    patternId?: string;
  };
  submit?: string;
}

/**
 * Step-scoped validation extracted from the React wizard.
 * Returns a fresh error bag for the given step based on the provided form model.
 */
export function validateLeagueWizardStep(
  form: LeagueConfigFormModel,
  step: WizardStep,
): WizardErrors {
  const errors: WizardErrors = {};

  if (step === 1) {
    const basicsErrors: NonNullable<WizardErrors['basics']> = {};
    if (!form.basics.name.trim()) {
      basicsErrors.name = 'Name is required';
    }
    if (!form.basics.visibility) {
      basicsErrors.visibility = 'Visibility is required';
    }
    if (Object.keys(basicsErrors).length > 0) {
      errors.basics = basicsErrors;
    }
  }

  if (step === 2) {
    const structureErrors: NonNullable<WizardErrors['structure']> = {};
    if (form.structure.mode === 'solo') {
      if (!form.structure.maxDrivers || form.structure.maxDrivers <= 0) {
        structureErrors.maxDrivers =
          'Max drivers must be greater than 0 for solo leagues';
      }
    } else if (form.structure.mode === 'fixedTeams') {
      if (!form.structure.maxTeams || form.structure.maxTeams <= 0) {
        structureErrors.maxTeams =
          'Max teams must be greater than 0 for team leagues';
      }
      if (!form.structure.driversPerTeam || form.structure.driversPerTeam <= 0) {
        structureErrors.driversPerTeam =
          'Drivers per team must be greater than 0';
      }
    }
    if (Object.keys(structureErrors).length > 0) {
      errors.structure = structureErrors;
    }
  }

  if (step === 3) {
    const timingsErrors: NonNullable<WizardErrors['timings']> = {};
    if (!form.timings.qualifyingMinutes || form.timings.qualifyingMinutes <= 0) {
      timingsErrors.qualifyingMinutes =
        'Qualifying duration must be greater than 0 minutes';
    }
    if (!form.timings.mainRaceMinutes || form.timings.mainRaceMinutes <= 0) {
      timingsErrors.mainRaceMinutes =
        'Main race duration must be greater than 0 minutes';
    }
    if (Object.keys(timingsErrors).length > 0) {
      errors.timings = timingsErrors;
    }
  }

  if (step === 4) {
    const scoringErrors: NonNullable<WizardErrors['scoring']> = {};
    if (!form.scoring.patternId && !form.scoring.customScoringEnabled) {
      scoringErrors.patternId =
        'Select a scoring preset or enable custom scoring';
    }
    if (Object.keys(scoringErrors).length > 0) {
      errors.scoring = scoringErrors;
    }
  }

  return errors;
}

/**
 * Helper to validate all steps (1-4) and merge errors into a single bag.
 */
export function validateAllLeagueWizardSteps(
  form: LeagueConfigFormModel,
): WizardErrors {
  const aggregate: WizardErrors = {};

  const merge = (next: WizardErrors) => {
    if (next.basics) {
      aggregate.basics = { ...aggregate.basics, ...next.basics };
    }
    if (next.structure) {
      aggregate.structure = { ...aggregate.structure, ...next.structure };
    }
    if (next.timings) {
      aggregate.timings = { ...aggregate.timings, ...next.timings };
    }
    if (next.scoring) {
      aggregate.scoring = { ...aggregate.scoring, ...next.scoring };
    }
    if (next.submit) {
      aggregate.submit = next.submit;
    }
  };

  merge(validateLeagueWizardStep(form, 1));
  merge(validateLeagueWizardStep(form, 2));
  merge(validateLeagueWizardStep(form, 3));
  merge(validateLeagueWizardStep(form, 4));

  return aggregate;
}

export function hasWizardErrors(errors: WizardErrors): boolean {
  return Object.keys(errors).some((key) => {
    const value = (errors as any)[key];
    if (!value) return false;
    if (typeof value === 'string') return true;
    return Object.keys(value).length > 0;
  });
}

/**
 * Pure mapping from LeagueConfigFormModel to the creation command.
 * Driver ownership is handled by the caller.
 */
export function buildCreateLeagueCommandFromConfig(
  form: LeagueConfigFormModel,
  ownerId: string,
): CreateLeagueWithSeasonAndScoringCommand {
  const structure = form.structure;
  let maxDrivers: number | undefined;
  let maxTeams: number | undefined;

  if (structure.mode === 'solo') {
    maxDrivers =
      typeof structure.maxDrivers === 'number' ? structure.maxDrivers : undefined;
    maxTeams = undefined;
  } else {
    const teams =
      typeof structure.maxTeams === 'number' ? structure.maxTeams : 0;
    const perTeam =
      typeof structure.driversPerTeam === 'number'
        ? structure.driversPerTeam
        : 0;
    maxTeams = teams > 0 ? teams : undefined;
    maxDrivers = teams > 0 && perTeam > 0 ? teams * perTeam : undefined;
  }

  return {
    name: form.basics.name.trim(),
    description: form.basics.description?.trim() || undefined,
    visibility: form.basics.visibility,
    ownerId,
    gameId: form.basics.gameId,
    maxDrivers,
    maxTeams,
    enableDriverChampionship: form.championships.enableDriverChampionship,
    enableTeamChampionship: form.championships.enableTeamChampionship,
    enableNationsChampionship: form.championships.enableNationsChampionship,
    enableTrophyChampionship: form.championships.enableTrophyChampionship,
    scoringPresetId: form.scoring.patternId || undefined,
  };
}

/**
 * Thin application-level facade that:
 * - pulls the current driver via repository
 * - builds the creation command
 * - delegates to the create-league use case
 */
export async function createLeagueFromConfig(
  form: LeagueConfigFormModel,
): Promise<CreateLeagueWithSeasonAndScoringResultDTO> {
  const driverRepo = getDriverRepository();
  const drivers = await driverRepo.findAll();
  const currentDriver = drivers[0];

  if (!currentDriver) {
    const error = new Error(
      'No driver profile found. Please create a driver profile first.',
    );
    (error as any).code = 'NO_DRIVER';
    throw error;
  }

  const useCase = getCreateLeagueWithSeasonAndScoringUseCase();
  const command = buildCreateLeagueCommandFromConfig(form, currentDriver.id);
  return useCase.execute(command);
}

/**
 * Apply scoring preset selection and derive timings, returning a new form model.
 * This mirrors the previous React handler but keeps it in testable, non-UI logic.
 */
export function applyScoringPresetToConfig(
  form: LeagueConfigFormModel,
  patternId: string,
): LeagueConfigFormModel {
  const lowerPresetId = patternId.toLowerCase();
  const timings = form.timings ?? ({} as LeagueConfigFormModel['timings']);
  let updatedTimings = { ...timings };

  if (lowerPresetId.includes('sprint') || lowerPresetId.includes('double')) {
    updatedTimings = {
      ...updatedTimings,
      practiceMinutes: 15,
      qualifyingMinutes: 20,
      sprintRaceMinutes: 20,
      mainRaceMinutes: 35,
      sessionCount: 2,
    };
  } else if (lowerPresetId.includes('endurance') || lowerPresetId.includes('long')) {
    updatedTimings = {
      ...updatedTimings,
      practiceMinutes: 30,
      qualifyingMinutes: 30,
      sprintRaceMinutes: undefined,
      mainRaceMinutes: 90,
      sessionCount: 1,
    };
  } else {
    updatedTimings = {
      ...updatedTimings,
      practiceMinutes: 20,
      qualifyingMinutes: 30,
      sprintRaceMinutes: undefined,
      mainRaceMinutes: 40,
      sessionCount: 1,
    };
  }

  return {
    ...form,
    scoring: {
      ...form.scoring,
      patternId,
      customScoringEnabled: false,
    },
    timings: updatedTimings,
  };
}