/**
 * Bracket Template System
 *
 * Defines pre-configured tournament bracket structures for various sports.
 * Templates specify rounds, match counts, and which rounds contribute to fantasy scoring.
 */

export interface BracketRound {
  /** Display name for this round (e.g., "First Four", "Elite Eight") */
  name: string;
  /** Number of matches in this round */
  matchCount: number;
  /** Name of the round that winners advance to (null for championship) */
  feedsInto: string | null;
  /** Whether this round affects fantasy points (false = 0 points per Q20) */
  isScoring: boolean;
}

export interface BracketTemplate {
  /** Unique identifier for this template */
  id: string;
  /** Human-readable name */
  name: string;
  /** Total number of teams in the bracket */
  totalTeams: number;
  /** Ordered list of rounds from earliest to championship */
  rounds: BracketRound[];
  /** Round name where fantasy scoring begins */
  scoringStartsAtRound: string;
}

/**
 * Simple 4-team bracket
 * Semifinals → Finals
 * All rounds score fantasy points
 */
export const SIMPLE_4: BracketTemplate = {
  id: "simple_4",
  name: "Simple 4-Team Bracket",
  totalTeams: 4,
  scoringStartsAtRound: "Semifinals",
  rounds: [
    {
      name: "Semifinals",
      matchCount: 2,
      feedsInto: "Finals",
      isScoring: true, // Losers share 3rd-4th
    },
    {
      name: "Finals",
      matchCount: 1,
      feedsInto: null,
      isScoring: true, // Winner 1st, Loser 2nd
    },
  ],
};

/**
 * Simple 8-team bracket
 * Quarterfinals → Semifinals → Finals
 * All rounds score fantasy points
 */
export const SIMPLE_8: BracketTemplate = {
  id: "simple_8",
  name: "Simple 8-Team Bracket",
  totalTeams: 8,
  scoringStartsAtRound: "Quarterfinals",
  rounds: [
    {
      name: "Quarterfinals",
      matchCount: 4,
      feedsInto: "Semifinals",
      isScoring: true, // Losers share 5th-8th
    },
    {
      name: "Semifinals",
      matchCount: 2,
      feedsInto: "Finals",
      isScoring: true, // Losers share 3rd-4th
    },
    {
      name: "Finals",
      matchCount: 1,
      feedsInto: null,
      isScoring: true, // Winner 1st, Loser 2nd
    },
  ],
};

/**
 * Simple 16-team bracket
 * Round of 16 → Quarterfinals → Semifinals → Finals
 * Only Quarterfinals and beyond score points (top 8)
 */
export const SIMPLE_16: BracketTemplate = {
  id: "simple_16",
  name: "Simple 16-Team Bracket",
  totalTeams: 16,
  scoringStartsAtRound: "Quarterfinals",
  rounds: [
    {
      name: "Round of 16",
      matchCount: 8,
      feedsInto: "Quarterfinals",
      isScoring: false, // Early elimination = 0 points
    },
    {
      name: "Quarterfinals",
      matchCount: 4,
      feedsInto: "Semifinals",
      isScoring: true, // Losers share 5th-8th
    },
    {
      name: "Semifinals",
      matchCount: 2,
      feedsInto: "Finals",
      isScoring: true, // Losers share 3rd-4th
    },
    {
      name: "Finals",
      matchCount: 1,
      feedsInto: null,
      isScoring: true, // Winner 1st, Loser 2nd
    },
  ],
};

/**
 * Simple 32-team bracket
 * Round of 32 → Round of 16 → Quarterfinals → Semifinals → Finals
 * Only Quarterfinals and beyond score points (top 8)
 */
export const SIMPLE_32: BracketTemplate = {
  id: "simple_32",
  name: "Simple 32-Team Bracket",
  totalTeams: 32,
  scoringStartsAtRound: "Quarterfinals",
  rounds: [
    {
      name: "Round of 32",
      matchCount: 16,
      feedsInto: "Round of 16",
      isScoring: false, // Early elimination = 0 points
    },
    {
      name: "Round of 16",
      matchCount: 8,
      feedsInto: "Quarterfinals",
      isScoring: false, // Early elimination = 0 points
    },
    {
      name: "Quarterfinals",
      matchCount: 4,
      feedsInto: "Semifinals",
      isScoring: true, // Losers share 5th-8th
    },
    {
      name: "Semifinals",
      matchCount: 2,
      feedsInto: "Finals",
      isScoring: true, // Losers share 3rd-4th
    },
    {
      name: "Finals",
      matchCount: 1,
      feedsInto: null,
      isScoring: true, // Winner 1st, Loser 2nd
    },
  ],
};

/**
 * NCAA March Madness (68 teams)
 * First Four (play-in) → Round of 64 → Round of 32 → Sweet Sixteen → Elite Eight → Final Four → Championship
 * Only Elite Eight and beyond score points per Q18
 */
export const NCAA_68: BracketTemplate = {
  id: "ncaa_68",
  name: "NCAA March Madness (68 teams)",
  totalTeams: 68,
  scoringStartsAtRound: "Elite Eight",
  rounds: [
    {
      name: "First Four",
      matchCount: 4,
      feedsInto: "Round of 64",
      isScoring: false, // Play-in games don't score
    },
    {
      name: "Round of 64",
      matchCount: 32,
      feedsInto: "Round of 32",
      isScoring: false,
    },
    {
      name: "Round of 32",
      matchCount: 16,
      feedsInto: "Sweet Sixteen",
      isScoring: false,
    },
    {
      name: "Sweet Sixteen",
      matchCount: 8,
      feedsInto: "Elite Eight",
      isScoring: false,
    },
    {
      name: "Elite Eight",
      matchCount: 4,
      feedsInto: "Final Four",
      isScoring: true, // Losers share 5th-8th
    },
    {
      name: "Final Four",
      matchCount: 2,
      feedsInto: "Championship",
      isScoring: true, // Losers share 3rd-4th
    },
    {
      name: "Championship",
      matchCount: 1,
      feedsInto: null,
      isScoring: true, // Winner 1st, Loser 2nd
    },
  ],
};

/**
 * NFL Playoffs (14 teams)
 * Wild Card → Divisional → Conference Championship → Super Bowl
 * Top 2 seeds get byes (skip Wild Card)
 * Scoring starts at Divisional (top 8)
 */
export const NFL_14: BracketTemplate = {
  id: "nfl_14",
  name: "NFL Playoffs (14 teams)",
  totalTeams: 14,
  scoringStartsAtRound: "Divisional",
  rounds: [
    {
      name: "Wild Card",
      matchCount: 6,
      feedsInto: "Divisional",
      isScoring: false, // 12 teams play, 2 have byes
    },
    {
      name: "Divisional",
      matchCount: 4,
      feedsInto: "Conference Championship",
      isScoring: true, // Quarterfinals - Losers share 5th-8th
    },
    {
      name: "Conference Championship",
      matchCount: 2,
      feedsInto: "Super Bowl",
      isScoring: true, // Semifinals - Losers share 3rd-4th
    },
    {
      name: "Super Bowl",
      matchCount: 1,
      feedsInto: null,
      isScoring: true, // Finals - Winner 1st, Loser 2nd
    },
  ],
};

/**
 * AFL Finals (10 teams with Wildcard Round from 2026)
 * Complex bracket with double-chance system for top 6 teams
 *
 * Structure:
 * - Wildcard Round: 7v10, 8v9 (losers eliminated with 0 points)
 * - Week 1 Finals:
 *   - Qualifying Finals: 1v4, 2v3 (losers get second chance)
 *   - Elimination Finals: 5v8(wildcard winner), 6v7(wildcard winner) (losers share 7th-8th)
 * - Week 2: Semi-Finals (QF losers vs EF winners, losers share 5th-6th)
 * - Week 3: Preliminary Finals (QF winners vs SF winners, losers share 3rd-4th)
 * - Week 4: Grand Final (1st vs 2nd)
 *
 * Note: This is NOT a simple single-elimination tree - it has double-chance paths
 */
export const AFL_10: BracketTemplate = {
  id: "afl_10",
  name: "AFL Finals (10 teams with Wildcard)",
  totalTeams: 10,
  scoringStartsAtRound: "Elimination Finals",
  rounds: [
    {
      name: "Wildcard Round",
      matchCount: 2,
      feedsInto: "Elimination Finals",
      isScoring: false, // Losers get 0 points (9th-10th)
    },
    {
      name: "Qualifying Finals",
      matchCount: 2,
      feedsInto: "Preliminary Finals", // Winners get bye
      isScoring: false, // Losers get second chance (go to Semi-Finals)
    },
    {
      name: "Elimination Finals",
      matchCount: 2,
      feedsInto: "Semi-Finals",
      isScoring: true, // Losers share 7th-8th
    },
    {
      name: "Semi-Finals",
      matchCount: 2,
      feedsInto: "Preliminary Finals",
      isScoring: true, // Losers share 5th-6th
    },
    {
      name: "Preliminary Finals",
      matchCount: 2,
      feedsInto: "Grand Final",
      isScoring: true, // Losers share 3rd-4th
    },
    {
      name: "Grand Final",
      matchCount: 1,
      feedsInto: null,
      isScoring: true, // Winner 1st, Loser 2nd
    },
  ],
};

/**
 * All available bracket templates
 */
export const BRACKET_TEMPLATES: Record<string, BracketTemplate> = {
  simple_4: SIMPLE_4,
  simple_8: SIMPLE_8,
  simple_16: SIMPLE_16,
  simple_32: SIMPLE_32,
  ncaa_68: NCAA_68,
  nfl_14: NFL_14,
  afl_10: AFL_10,
};

/**
 * Get a bracket template by ID
 */
export function getBracketTemplate(id: string): BracketTemplate | undefined {
  return BRACKET_TEMPLATES[id];
}

/**
 * Get all bracket templates as an array
 */
export function getAllBracketTemplates(): BracketTemplate[] {
  return Object.values(BRACKET_TEMPLATES);
}

/**
 * Helper to determine scoring round type based on match count in scoring rounds
 * Used for determining placement sharing (5-8th, 3-4th, 1-2nd)
 *
 * Special handling for AFL finals system which has specific placement rules
 */
export function getScoringRoundType(
  roundName: string,
  template: BracketTemplate
): "quarterfinals" | "semifinals" | "finals" | null {
  const round = template.rounds.find((r) => r.name === roundName);
  if (!round || !round.isScoring) return null;

  // Special handling for AFL finals
  if (template.id === "afl_10") {
    if (roundName === "Elimination Finals") return "quarterfinals"; // Losers share 7-8th
    if (roundName === "Semi-Finals") return "quarterfinals"; // Losers share 5-6th (custom mapping)
    if (roundName === "Preliminary Finals") return "semifinals"; // Losers share 3-4th
    if (roundName === "Grand Final") return "finals"; // 1st and 2nd
    return null;
  }

  // Standard logic for other templates
  // Determine type by match count in scoring round
  if (round.matchCount === 4) return "quarterfinals"; // 8 teams, losers share 5-8th
  if (round.matchCount === 2) return "semifinals"; // 4 teams, losers share 3-4th
  if (round.matchCount === 1) return "finals"; // 2 teams, 1st and 2nd
  return null;
}