import { database } from "~/database/context";
import * as schema from "~/database/schema";
import { eq, and, inArray } from "drizzle-orm";
import { getScoringRules, calculateFantasyPoints, calculateAveragedPoints } from "./scoring-rules";

/**
 * Core scoring calculation engine
 * This file contains the logic for calculating fantasy points based on participant results
 */

export type ScoringPattern =
  | "single_elimination_playoff"
  | "page_playoff"
  | "season_standings"
  | "qualifying_points";

/**
 * Process a playoff event completion and assign final placements
 * Implementation will be added in Phase 2
 */
export async function processPlayoffEvent(
  eventId: string,
  providedDb?: ReturnType<typeof database>
): Promise<void> {
  const db = providedDb || database();

  // TODO: Implement in Phase 2
  // 1. Get event and determine round (QF, SF, Finals)
  // 2. Get matches and determine winners/losers
  // 3. Assign shared placements based on elimination round
  // 4. Update participantResults with final placements
  // 5. Trigger recalculation for affected leagues

  console.log(`[ScoringCalculator] processPlayoffEvent not yet implemented: ${eventId}`);
}

/**
 * Process a qualifying event completion and update QP totals
 * Implementation will be added in Phase 3
 */
export async function processQualifyingEvent(
  eventId: string,
  providedDb?: ReturnType<typeof database>
): Promise<void> {
  const db = providedDb || database();

  // TODO: Implement in Phase 3
  // 1. Get event results
  // 2. Award qualifying points based on placement
  // 3. Update participant_qualifying_totals
  // 4. Check if all majors complete
  // 5. Update QP standings displays

  console.log(`[ScoringCalculator] processQualifyingEvent not yet implemented: ${eventId}`);
}

/**
 * Finalize qualifying points and convert to fantasy placements
 * Called manually by admin when all majors are complete
 * Implementation will be added in Phase 3
 */
export async function finalizeQualifyingPoints(
  sportsSeasonId: string,
  providedDb?: ReturnType<typeof database>
): Promise<void> {
  const db = providedDb || database();

  // TODO: Implement in Phase 3
  // 1. Get all participants ranked by total QP
  // 2. Handle ties in QP (share placements)
  // 3. Assign final placements (1-8) based on QP ranking
  // 4. Update participantResults with final placements
  // 5. Mark sports season as finalized
  // 6. Trigger recalculation for all affected leagues

  console.log(
    `[ScoringCalculator] finalizeQualifyingPoints not yet implemented: ${sportsSeasonId}`
  );
}

/**
 * Process season standings (F1) and assign final placements
 * Implementation will be added in Phase 3
 */
export async function processSeasonStandings(
  sportsSeasonId: string,
  providedDb?: ReturnType<typeof database>
): Promise<void> {
  const db = providedDb || database();

  // TODO: Implement in Phase 3
  // 1. Get final season standings from participant_season_results
  // 2. Assign final placements (1-8) based on standings
  // 3. Update participantResults with final placements
  // 4. Trigger recalculation for all affected leagues

  console.log(
    `[ScoringCalculator] processSeasonStandings not yet implemented: ${sportsSeasonId}`
  );
}

/**
 * Calculate total fantasy points for a team in a specific season
 * Sums points from all drafted participants based on their final placements
 */
export async function calculateTeamScore(
  teamId: string,
  seasonId: string,
  providedDb?: ReturnType<typeof database>
): Promise<{
  totalPoints: number;
  placementCounts: Record<number, number>;
  participantsCompleted: number;
  participantsTotal: number;
}> {
  const db = providedDb || database();

  // Get season scoring rules
  const scoringRules = await getScoringRules(seasonId, db);
  if (!scoringRules) {
    throw new Error(`Season ${seasonId} not found`);
  }

  // Get all draft picks for this team
  const picks = await db.query.draftPicks.findMany({
    where: and(
      eq(schema.draftPicks.teamId, teamId),
      eq(schema.draftPicks.seasonId, seasonId)
    ),
    with: {
      participant: {
        with: {
          results: true,
        },
      },
    },
  });

  let totalPoints = 0;
  const placementCounts: Record<number, number> = {
    1: 0,
    2: 0,
    3: 0,
    4: 0,
    5: 0,
    6: 0,
    7: 0,
    8: 0,
  };
  let participantsCompleted = 0;

  for (const pick of picks) {
    const result = pick.participant.results[0]; // Should only be one result per participant

    if (result && result.finalPosition) {
      const points = calculateFantasyPoints(result.finalPosition, scoringRules);
      totalPoints += points;
      participantsCompleted++;

      // Track placement for tiebreakers
      if (result.finalPosition >= 1 && result.finalPosition <= 8) {
        placementCounts[result.finalPosition]++;
      }
    }
  }

  return {
    totalPoints,
    placementCounts,
    participantsCompleted,
    participantsTotal: picks.length,
  };
}

/**
 * Recalculate standings for all teams in a season
 * Called after any scoring event completes or participant results change
 * Implementation will be completed in Phase 4
 */
export async function recalculateStandings(
  seasonId: string,
  providedDb?: ReturnType<typeof database>
): Promise<void> {
  const db = providedDb || database();

  // TODO: Complete implementation in Phase 4
  // For now, calculate basic scores without rankings

  const teams = await db.query.teams.findMany({
    where: eq(schema.teams.seasonId, seasonId),
  });

  for (const team of teams) {
    const teamScore = await calculateTeamScore(team.id, seasonId, db);

    // Upsert team standings
    const existing = await db.query.teamStandings.findFirst({
      where: and(
        eq(schema.teamStandings.teamId, team.id),
        eq(schema.teamStandings.seasonId, seasonId)
      ),
    });

    if (existing) {
      await db
        .update(schema.teamStandings)
        .set({
          totalPoints: teamScore.totalPoints.toString(),
          firstPlaceCount: teamScore.placementCounts[1],
          secondPlaceCount: teamScore.placementCounts[2],
          thirdPlaceCount: teamScore.placementCounts[3],
          fourthPlaceCount: teamScore.placementCounts[4],
          fifthPlaceCount: teamScore.placementCounts[5],
          sixthPlaceCount: teamScore.placementCounts[6],
          seventhPlaceCount: teamScore.placementCounts[7],
          eighthPlaceCount: teamScore.placementCounts[8],
          participantsRemaining:
            teamScore.participantsTotal - teamScore.participantsCompleted,
          calculatedAt: new Date(),
        })
        .where(eq(schema.teamStandings.id, existing.id));
    } else {
      await db.insert(schema.teamStandings).values({
        teamId: team.id,
        seasonId,
        totalPoints: teamScore.totalPoints.toString(),
        currentRank: 1, // Will be updated when we add ranking logic
        firstPlaceCount: teamScore.placementCounts[1],
        secondPlaceCount: teamScore.placementCounts[2],
        thirdPlaceCount: teamScore.placementCounts[3],
        fourthPlaceCount: teamScore.placementCounts[4],
        fifthPlaceCount: teamScore.placementCounts[5],
        sixthPlaceCount: teamScore.placementCounts[6],
        seventhPlaceCount: teamScore.placementCounts[7],
        eighthPlaceCount: teamScore.placementCounts[8],
        participantsRemaining: teamScore.participantsTotal - teamScore.participantsCompleted,
      });
    }
  }

  console.log(`[ScoringCalculator] Recalculated standings for season ${seasonId}`);
}

/**
 * Recalculate standings for all leagues that include a specific sports season
 * Called after a sports season event completes
 */
export async function recalculateAffectedLeagues(
  sportsSeasonId: string,
  providedDb?: ReturnType<typeof database>
): Promise<void> {
  const db = providedDb || database();

  // Get all fantasy seasons that include this sports season
  const seasonSports = await db.query.seasonSports.findMany({
    where: eq(schema.seasonSports.sportsSeasonId, sportsSeasonId),
  });

  const seasonIds = seasonSports.map((ss) => ss.seasonId);

  // Recalculate each affected season
  for (const seasonId of seasonIds) {
    await recalculateStandings(seasonId, db);
  }

  console.log(
    `[ScoringCalculator] Recalculated ${seasonIds.length} affected season(s) for sports season ${sportsSeasonId}`
  );
}