import { database } from "~/database/context";
import { eq, isNull, or } from "drizzle-orm";
import * as schema from "~/database/schema";
import { findParticipantsBySportsSeasonId, updateParticipant } from "~/models/season-participant";
import { upsertSeasonMatchBulk, upsertMatchSubGame } from "~/models/season-match";
import { setMatchWinner, updatePlayoffMatch, advanceWinnerTemplate, findPlayoffMatchesByEventId } from "~/models/playoff-match";
import { processMatchResult, autoCompleteRoundIfDone } from "~/models/scoring-calculator";
import { findMatchingTeamName } from "~/lib/normalize-team-name";
import { getBracketTemplate } from "~/lib/bracket-templates";
import { PandaScoreMatchSyncAdapter } from "./pandascore";
import { EspnScheduleAdapter } from "./espn-schedule";
import type { MatchSyncAdapter, MatchSyncResult, MatchRecord } from "./types";
import { logger } from "~/lib/logger";

function getMatchSyncAdapter(simulatorType: string): MatchSyncAdapter {
  switch (simulatorType) {
    case "cs2_major_qualifying_points":
      return new PandaScoreMatchSyncAdapter();
    case "mlb_bracket":
      return new EspnScheduleAdapter("baseball/mlb");
    case "nba_bracket":
      return new EspnScheduleAdapter("basketball/nba");
    case "mls_bracket":
      return new EspnScheduleAdapter("soccer/mls");
    case "wnba_bracket":
      return new EspnScheduleAdapter("basketball/wnba");
    case "nhl_bracket":
      return new EspnScheduleAdapter("hockey/nhl");
    default:
      throw new Error(
        `No match sync adapter available for simulator type "${simulatorType}". ` +
          "CS2, MLB, NBA, MLS, WNBA, and NHL are currently supported."
      );
  }
}

export async function syncMatches(sportsSeasonId: string): Promise<MatchSyncResult> {
  const db = database();

  const sportsSeason = await db.query.sportsSeasons.findFirst({
    where: eq(schema.sportsSeasons.id, sportsSeasonId),
    with: { sport: true },
  });

  if (!sportsSeason) throw new Error(`Sports season ${sportsSeasonId} not found`);

  const externalSeasonId = sportsSeason.externalSeasonId;
  if (!externalSeasonId) {
    throw new Error(`Sports season "${sportsSeason.name}" has no externalSeasonId configured`);
  }

  const simulatorType = sportsSeason.sport?.simulatorType;
  if (!simulatorType) {
    throw new Error(`Sport "${sportsSeason.sport?.name ?? "(none)"}" has no simulator type configured`);
  }

  const adapter = getMatchSyncAdapter(simulatorType);
  const fetchedMatches = await adapter.fetchMatches(externalSeasonId);

  // Load participants, build lookup maps
  const participants = await findParticipantsBySportsSeasonId(sportsSeasonId);
  const participantNames = participants.map((p) => p.name);
  const participantByExternalId = new Map(
    participants.filter((p) => p.externalId).map((p) => [p.externalId!, p])
  );
  const participantByName = new Map(participants.map((p) => [p.name, p]));

  async function resolveParticipant(externalId: string, name: string) {
    let participant = participantByExternalId.get(externalId) ?? null;
    if (!participant) {
      const matchedName = findMatchingTeamName(name, participantNames);
      if (matchedName) {
        participant = participantByName.get(matchedName) ?? null;
        if (participant && !participant.externalId) {
          await updateParticipant(participant.id, { externalId });
          participantByExternalId.set(externalId, participant);
        }
      }
    }
    return participant;
  }

  // Find the scoring event for this sports season (needed for CS2 stage lookup + playoff sync)
  const scoringEvents = await db.query.scoringEvents.findMany({
    where: eq(schema.scoringEvents.sportsSeasonId, sportsSeasonId),
  });

  // Split matches: Swiss (matchStage set) vs playoff bracket (matchStage null)
  const swissMatches = fetchedMatches.filter((m) => m.matchStage != null);
  const bracketMatches = fetchedMatches.filter((m) => m.matchStage == null);

  const unmatchedTeams: MatchSyncResult["unmatchedTeams"] = [];
  const errors: MatchSyncResult["errors"] = [];
  let swissCreated = 0;
  let swissUpdated = 0;
  let playoffUpdated = 0;

  // --- Swiss matches → season_matches ---
  if (swissMatches.length > 0) {
    // For CS2, use the scoring event that has cs2_major_stage_results
    const cs2Event = scoringEvents.find((e) => e.isQualifyingEvent) ?? scoringEvents[0] ?? null;

    const toUpsert = [];
    for (const m of swissMatches) {
      const p1 = await resolveParticipant(m.team1ExternalId, m.team1Name);
      const p2 = await resolveParticipant(m.team2ExternalId, m.team2Name);

      if (!p1) unmatchedTeams.push({ externalId: m.team1ExternalId, name: m.team1Name });
      if (!p2) unmatchedTeams.push({ externalId: m.team2ExternalId, name: m.team2Name });

      const winnerParticipant = m.winnerExternalId
        ? (await resolveParticipant(m.winnerExternalId, ""))
        : null;

      toUpsert.push({
        sportsSeasonId,
        scoringEventId: cs2Event?.id ?? null,
        participant1Id: p1?.id ?? null,
        participant2Id: p2?.id ?? null,
        winnerId: winnerParticipant?.id ?? null,
        participant1Score: m.team1Score,
        participant2Score: m.team2Score,
        matchStage: m.matchStage ?? null,
        matchRound: m.matchRound ?? null,
        matchday: m.matchday ?? null,
        isSeries: m.isSeries ?? false,
        status: m.status,
        scheduledAt: m.scheduledAt,
        startedAt: m.startedAt,
        completedAt: m.completedAt,
        externalMatchId: m.externalMatchId,
      });
    }

    const upserted = await upsertSeasonMatchBulk(toUpsert);

    // Track created vs updated (rough heuristic: if completedAt is within last 2 min, it's new)
    swissCreated = upserted.filter((r) => {
      const diff = r.createdAt ? Date.now() - r.createdAt.getTime() : Infinity;
      return diff < 120_000;
    }).length;
    swissUpdated = upserted.length - swissCreated;

    // Upsert sub-games (maps) for matches with subGames
    for (const m of swissMatches) {
      if (!m.subGames?.length) continue;
      const upsertedMatch = upserted.find((u) => u.externalMatchId === m.externalMatchId);
      if (!upsertedMatch) continue;
      for (const g of m.subGames) {
        const winnerParticipant = g.winnerExternalId
          ? (await resolveParticipant(g.winnerExternalId, ""))
          : null;
        try {
          await upsertMatchSubGame({
            seasonMatchId: upsertedMatch.id,
            gameNumber: g.gameNumber,
            gameLabel: g.gameLabel ?? null,
            participant1Score: g.team1Score,
            participant2Score: g.team2Score,
            winnerId: winnerParticipant?.id ?? null,
            status: g.status,
            externalGameId: g.externalGameId ?? null,
          });
        } catch (err) {
          logger.error(`[match-sync] Error upserting sub-game ${g.gameNumber} for match ${m.externalMatchId}:`, err);
        }
      }
    }
  }

  // --- Bracket matches → playoff_matches ---
  if (bracketMatches.length > 0) {
    for (const event of scoringEvents) {
      const existingPlayoffMatches = await findPlayoffMatchesByEventId(event.id);
      if (existingPlayoffMatches.length === 0) continue;

      const bracketTemplate = event.bracketTemplateId
        ? getBracketTemplate(event.bracketTemplateId)
        : null;

      for (const m of bracketMatches) {
        if (m.status !== "complete") continue;

        const p1 = await resolveParticipant(m.team1ExternalId, m.team1Name);
        const p2 = await resolveParticipant(m.team2ExternalId, m.team2Name);
        if (!p1 || !p2) continue;

        const winnerParticipant = m.winnerExternalId
          ? await resolveParticipant(m.winnerExternalId, "")
          : null;
        if (!winnerParticipant) continue;

        const loserId = winnerParticipant.id === p1.id ? p2.id : p1.id;

        // Find the matching playoff_matches row: prefer external_match_id match, fall back to participant ID match
        let playoffMatch = existingPlayoffMatches.find(
          (pm) => pm.externalMatchId === m.externalMatchId
        );
        if (!playoffMatch) {
          playoffMatch = existingPlayoffMatches.find(
            (pm) =>
              !pm.isComplete &&
              ((pm.participant1Id === p1.id && pm.participant2Id === p2.id) ||
                (pm.participant1Id === p2.id && pm.participant2Id === p1.id))
          );
        }

        if (!playoffMatch) continue;
        if (playoffMatch.isComplete && playoffMatch.winnerId) continue; // idempotent

        try {
          await setMatchWinner(
            playoffMatch.id,
            winnerParticipant.id,
            loserId,
            winnerParticipant.id === p1.id ? (m.team1Score ?? undefined) : (m.team2Score ?? undefined),
            winnerParticipant.id === p1.id ? (m.team2Score ?? undefined) : (m.team1Score ?? undefined)
          );

          // Set external_match_id for future upserts
          if (!playoffMatch.externalMatchId) {
            await updatePlayoffMatch(playoffMatch.id, { externalMatchId: m.externalMatchId });
          }

          if (bracketTemplate) {
            try {
              await advanceWinnerTemplate(playoffMatch.id, winnerParticipant.id, bracketTemplate);
            } catch (err) {
              if (!(err instanceof Error && err.message.includes("already filled"))) throw err;
            }
          }

          const roundIsScoring = bracketTemplate?.rounds.find(
            (r) => r.name === playoffMatch!.round
          )?.isScoring;

          await processMatchResult({
            round: playoffMatch.round,
            winnerId: winnerParticipant.id,
            loserId,
            isScoring: roundIsScoring !== undefined ? roundIsScoring : (playoffMatch.isScoring ?? true),
            sportsSeasonId,
            bracketTemplateId: event.bracketTemplateId ?? null,
            eventId: event.id,
            eventName: event.name ?? undefined,
            matchId: playoffMatch.id,
            loserAdvances: false,
          });

          await autoCompleteRoundIfDone(event.id, playoffMatch.round, sportsSeasonId, db);

          playoffUpdated++;
        } catch (err) {
          logger.error(`[match-sync] Error processing playoff match ${m.externalMatchId}:`, err);
          errors.push({
            externalMatchId: m.externalMatchId,
            error: err instanceof Error ? err.message : String(err),
          });
        }
      }
    }
  }

  return { swissCreated, swissUpdated, playoffUpdated, unmatchedTeams, errors };
}