import { database } from "~/database/context";
import * as schema from "~/database/schema";
import { eq, and, desc } from "drizzle-orm";
import type { TeamStanding, TeamStandingSnapshot } from "~/types/standings";

// Re-export types from shared types file
export type { TeamStanding, TeamStandingSnapshot } from "~/types/standings";

/**
 * Get current standings for a season
 */
export async function getSeasonStandings(
  seasonId: string,
  providedDb?: ReturnType<typeof database>
): Promise<TeamStanding[]> {
  const db = providedDb || database();

  const standings = await db.query.teamStandings.findMany({
    where: eq(schema.teamStandings.seasonId, seasonId),
    with: {
      team: true,
    },
  });

  // Sort by currentRank ascending (1 is best, 2 is second, etc.)
  const sorted = standings.sort((a, b) => a.currentRank - b.currentRank);

  return sorted.map((standing) => ({
    teamId: standing.teamId,
    teamName: standing.team.name,
    totalPoints: parseFloat(standing.totalPoints),
    currentRank: standing.currentRank,
    previousRank: standing.previousRank,
    rankChange: standing.previousRank
      ? standing.previousRank - standing.currentRank
      : 0,
    placementCounts: {
      first: standing.firstPlaceCount,
      second: standing.secondPlaceCount,
      third: standing.thirdPlaceCount,
      fourth: standing.fourthPlaceCount,
      fifth: standing.fifthPlaceCount,
      sixth: standing.sixthPlaceCount,
      seventh: standing.seventhPlaceCount,
      eighth: standing.eighthPlaceCount,
    },
    participantsRemaining: standing.participantsRemaining,
    calculatedAt: standing.calculatedAt,
    // Phase 5.4: Include projected points
    actualPoints: standing.actualPoints ? parseFloat(standing.actualPoints) : null,
    projectedPoints: standing.projectedPoints ? parseFloat(standing.projectedPoints) : null,
    participantsFinished: standing.participantsFinished,
  }));
}

/**
 * Get standings for a specific team
 */
export async function getTeamStanding(
  teamId: string,
  seasonId: string,
  providedDb?: ReturnType<typeof database>
): Promise<TeamStanding | null> {
  const db = providedDb || database();

  const standing = await db.query.teamStandings.findFirst({
    where: and(
      eq(schema.teamStandings.teamId, teamId),
      eq(schema.teamStandings.seasonId, seasonId)
    ),
    with: {
      team: true,
    },
  });

  if (!standing) return null;

  return {
    teamId: standing.teamId,
    teamName: standing.team.name,
    totalPoints: parseFloat(standing.totalPoints),
    currentRank: standing.currentRank,
    previousRank: standing.previousRank,
    rankChange: standing.previousRank
      ? standing.previousRank - standing.currentRank
      : 0,
    placementCounts: {
      first: standing.firstPlaceCount,
      second: standing.secondPlaceCount,
      third: standing.thirdPlaceCount,
      fourth: standing.fourthPlaceCount,
      fifth: standing.fifthPlaceCount,
      sixth: standing.sixthPlaceCount,
      seventh: standing.seventhPlaceCount,
      eighth: standing.eighthPlaceCount,
    },
    participantsRemaining: standing.participantsRemaining,
    calculatedAt: standing.calculatedAt,
    // Phase 5.4: Include projected points
    actualPoints: standing.actualPoints ? parseFloat(standing.actualPoints) : null,
    projectedPoints: standing.projectedPoints ? parseFloat(standing.projectedPoints) : null,
    participantsFinished: standing.participantsFinished,
  };
}

/**
 * Get detailed team breakdown with all picks and their points
 */
export async function getTeamScoreBreakdown(
  teamId: string,
  seasonId: string,
  providedDb?: ReturnType<typeof database>
) {
  const db = providedDb || database();

  // Get season scoring rules
  const season = await db.query.seasons.findFirst({
    where: eq(schema.seasons.id, seasonId),
  });

  if (!season) return null;

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

  // Get scoring rules for EV calculation
  const scoringRules = {
    pointsFor1st: season.pointsFor1st,
    pointsFor2nd: season.pointsFor2nd,
    pointsFor3rd: season.pointsFor3rd,
    pointsFor4th: season.pointsFor4th,
    pointsFor5th: season.pointsFor5th,
    pointsFor6th: season.pointsFor6th,
    pointsFor7th: season.pointsFor7th,
    pointsFor8th: season.pointsFor8th,
  };

  // Calculate points and projected points for each pick
  const pickBreakdown = await Promise.all(
    picks.map(async (pick) => {
      const result = pick.participant.results[0];
      let points = 0;
      let projectedPoints: number | null = null;

      if (result && result.finalPosition) {
        // Calculate points based on placement
        const pointsMap: Record<number, number> = {
          1: season.pointsFor1st,
          2: season.pointsFor2nd,
          3: season.pointsFor3rd,
          4: season.pointsFor4th,
          5: season.pointsFor5th,
          6: season.pointsFor6th,
          7: season.pointsFor7th,
          8: season.pointsFor8th,
        };
        points = pointsMap[result.finalPosition] || 0;
        projectedPoints = points; // Finished = projected equals actual
      } else {
        // Participant is unfinished - get EV
        const { getParticipantEV } = await import("./participant-expected-value");
        const { calculateEV } = await import("~/services/ev-calculator");

        const ev = await getParticipantEV(
          pick.participant.id,
          pick.participant.sportsSeasonId
        );

        if (ev) {
          const probabilities = {
            probFirst: parseFloat(ev.probFirst),
            probSecond: parseFloat(ev.probSecond),
            probThird: parseFloat(ev.probThird),
            probFourth: parseFloat(ev.probFourth),
            probFifth: parseFloat(ev.probFifth),
            probSixth: parseFloat(ev.probSixth),
            probSeventh: parseFloat(ev.probSeventh),
            probEighth: parseFloat(ev.probEighth),
          };

          projectedPoints = calculateEV(probabilities, scoringRules);
        }
      }

      return {
        pickNumber: pick.pickNumber,
        round: pick.round,
        participant: {
          id: pick.participant.id,
          name: pick.participant.name,
          sport: pick.participant.sportsSeason.sport.name,
          sportsSeasonId: pick.participant.sportsSeasonId,
        },
        finalPosition: result?.finalPosition ?? null,
        points,
        projectedPoints,
        // A participant is complete if they have a result record (even if finalPosition is 0)
        isComplete: !!result,
      };
    })
  );

  // Group by sport for easier display
  // Structure: { sportName: { sportsSeasonId, picks } }
  const bySport: Record<string, { sportsSeasonId: string; picks: typeof pickBreakdown }> = {};
  for (const pick of pickBreakdown) {
    const sport = pick.participant.sport;
    if (!bySport[sport]) {
      bySport[sport] = {
        sportsSeasonId: pick.participant.sportsSeasonId,
        picks: [],
      };
    }
    bySport[sport].picks.push(pick);
  }

  const actualPoints = pickBreakdown
    .filter((p) => p.isComplete)
    .reduce((sum, p) => sum + p.points, 0);

  const projectedTotalPoints = pickBreakdown.reduce(
    (sum, p) => sum + (p.projectedPoints ?? 0),
    0
  );

  return {
    team: await db.query.teams.findFirst({
      where: eq(schema.teams.id, teamId),
    }),
    picks: pickBreakdown,
    bySport,
    totalPoints: pickBreakdown.reduce((sum, p) => sum + p.points, 0),
    actualPoints,
    projectedPoints: projectedTotalPoints,
    completedCount: pickBreakdown.filter((p) => p.isComplete).length,
    totalCount: pickBreakdown.length,
  };
}

/**
 * Get historical standings snapshots for a team
 * Used to display point progression over time
 */
export async function getTeamStandingsHistory(
  teamId: string,
  seasonId: string,
  providedDb?: ReturnType<typeof database>
): Promise<TeamStandingSnapshot[]> {
  const db = providedDb || database();

  const snapshots = await db.query.teamStandingsSnapshots.findMany({
    where: and(
      eq(schema.teamStandingsSnapshots.teamId, teamId),
      eq(schema.teamStandingsSnapshots.seasonId, seasonId)
    ),
    orderBy: schema.teamStandingsSnapshots.snapshotDate,
  });

  return snapshots.map((snapshot) => ({
    date: new Date(snapshot.snapshotDate),
    rank: snapshot.rank,
    totalPoints: parseFloat(snapshot.totalPoints),
  }));
}

/**
 * Get standings comparison between current and 7 days ago
 * Used for "7-day change" display
 */
export async function getSevenDayStandingsChange(
  seasonId: string,
  providedDb?: ReturnType<typeof database>
) {
  const db = providedDb || database();

  const sevenDaysAgo = new Date();
  sevenDaysAgo.setDate(sevenDaysAgo.getDate() - 7);

  // Get current standings
  const current = await getSeasonStandings(seasonId, db);

  // Get snapshots from 7 days ago
  const snapshots = await db.query.teamStandingsSnapshots.findMany({
    where: and(
      eq(schema.teamStandingsSnapshots.seasonId, seasonId),
      eq(schema.teamStandingsSnapshots.snapshotDate, sevenDaysAgo.toISOString().split("T")[0])
    ),
  });

  // Create a map of team -> old rank
  const oldRanks = new Map<string, number>();
  for (const snapshot of snapshots) {
    oldRanks.set(snapshot.teamId, snapshot.rank);
  }

  // Add 7-day changes to current standings
  return current.map((standing) => ({
    ...standing,
    sevenDayRankChange: oldRanks.has(standing.teamId)
      ? oldRanks.get(standing.teamId)! - standing.currentRank
      : 0,
    sevenDayOldRank: oldRanks.get(standing.teamId) || null,
  }));
}

/**
 * Create a daily standings snapshot
 * Should be called by a scheduled job once per day
 */
export async function createDailySnapshot(
  seasonId: string,
  providedDb?: ReturnType<typeof database>
): Promise<void> {
  const db = providedDb || database();

  const today = new Date().toISOString().split("T")[0];

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

  for (const standing of standings) {
    // Check if snapshot already exists for today
    const existing = await db.query.teamStandingsSnapshots.findFirst({
      where: and(
        eq(schema.teamStandingsSnapshots.teamId, standing.teamId),
        eq(schema.teamStandingsSnapshots.seasonId, seasonId),
        eq(schema.teamStandingsSnapshots.snapshotDate, today)
      ),
    });

    if (!existing) {
      await db.insert(schema.teamStandingsSnapshots).values({
        teamId: standing.teamId,
        seasonId,
        snapshotDate: today,
        totalPoints: standing.totalPoints,
        rank: standing.currentRank,
        firstPlaceCount: standing.firstPlaceCount,
        secondPlaceCount: standing.secondPlaceCount,
        thirdPlaceCount: standing.thirdPlaceCount,
        fourthPlaceCount: standing.fourthPlaceCount,
        fifthPlaceCount: standing.fifthPlaceCount,
        sixthPlaceCount: standing.sixthPlaceCount,
        seventhPlaceCount: standing.seventhPlaceCount,
        eighthPlaceCount: standing.eighthPlaceCount,
        participantsRemaining: standing.participantsRemaining,
        // Phase 5.4: Copy projected points tracking
        actualPoints: standing.actualPoints,
        projectedPoints: standing.projectedPoints,
        participantsFinished: standing.participantsFinished,
      });
    }
  }

  console.log(`[Standings] Created daily snapshot for season ${seasonId}`);
}

/**
 * Get point progression data for all teams in a season
 * Returns historical snapshots organized by team for charting
 */
export async function getSeasonPointProgression(
  seasonId: string,
  providedDb?: ReturnType<typeof database>
) {
  const db = providedDb || database();

  // Get all snapshots for this season
  const snapshots = await db.query.teamStandingsSnapshots.findMany({
    where: eq(schema.teamStandingsSnapshots.seasonId, seasonId),
    orderBy: schema.teamStandingsSnapshots.snapshotDate,
    with: {
      team: true,
    },
  });

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

  // Organize data by date
  const dateMap = new Map<string, any>();

  for (const snapshot of snapshots) {
    const date = snapshot.snapshotDate;

    if (!dateMap.has(date)) {
      dateMap.set(date, { date });
    }

    const dateData = dateMap.get(date);
    dateData[snapshot.team.name] = parseFloat(snapshot.totalPoints);
  }

  // Convert to array and sort by date
  const chartData = Array.from(dateMap.values()).sort((a, b) =>
    new Date(a.date).getTime() - new Date(b.date).getTime()
  );

  return {
    chartData,
    teams: teams.map(t => ({ id: t.id, name: t.name })),
  };
}