/**
 * API Response Transformers
 * Converts legacy CSGO:WTF API responses to the new CS2.WTF format
 *
 * IMPORTANT: The backend API returns data in a legacy format that differs from our TypeScript schemas.
 * These transformers bridge that gap by:
 * 1. Converting Unix timestamps to ISO 8601 strings
 * 2. Splitting score arrays [team_a, team_b] into separate fields
 * 3. Renaming fields (parsed → demo_parsed, vac → vac_present, etc.)
 * 4. Constructing full avatar URLs from hashes
 * 5. Normalizing team IDs (1/2 → 2/3)
 *
 * Always use these transformers before passing API data to Zod schemas or TypeScript types.
 */

import type { MatchListItem, MatchesListResponse, Match, MatchPlayer } from '$lib/types';

/**
 * Legacy API match list item format (from api.csgow.tf)
 *
 * VERIFIED: This interface matches the actual API response from GET /matches
 * Tested: 2025-11-12 via curl https://api.csgow.tf/matches?limit=2
 */
export interface LegacyMatchListItem {
	match_id: string; // uint64 as string
	map: string; // Can be empty string if not parsed
	date: number; // Unix timestamp (seconds since epoch)
	score: [number, number]; // [team_a_score, team_b_score]
	duration: number; // Match duration in seconds
	match_result: number; // 0 = tie, 1 = team_a win, 2 = team_b win
	max_rounds: number; // 24 for MR12, 30 for MR15
	parsed: boolean; // Whether demo has been parsed (NOT demo_parsed)
	vac: boolean; // Whether any player has VAC ban (NOT vac_present)
	game_ban: boolean; // Whether any player has game ban (NOT gameban_present)
}

/**
 * Legacy API match detail format (from GET /match/:id)
 *
 * VERIFIED: This interface matches the actual API response
 * Tested: 2025-11-12 via curl https://api.csgow.tf/match/3589487716842078322
 *
 * Note: Uses 'stats' array, not 'players' array
 */
export interface LegacyMatchDetail {
	match_id: string;
	share_code?: string;
	map: string;
	date: number; // Unix timestamp
	score: [number, number]; // [team_a, team_b]
	duration: number;
	match_result: number;
	max_rounds: number;
	parsed: boolean; // NOT demo_parsed
	vac: boolean; // NOT vac_present
	game_ban: boolean; // NOT gameban_present
	stats?: LegacyPlayerStats[]; // Player stats array
}

/**
 * Legacy player stats format (nested within match detail)
 *
 * VERIFIED: Matches actual API response structure
 * - Player info nested under 'player' object
 * - Rank as object with 'old' and 'new' properties
 * - Multi-kills as object with 'duo', 'triple', 'quad', 'ace'
 * - Damage as object with 'enemy' and 'team'
 * - Flash stats with nested 'duration' and 'total' objects
 */
export interface LegacyPlayerStats {
	team_id: number;
	kills: number;
	deaths: number;
	assists: number;
	headshot: number;
	mvp: number;
	score: number;
	player: {
		steamid64: string;
		name: string;
		avatar: string;
		vac: boolean;
		game_ban: boolean;
		vanity_url?: string;
	};
	rank: Record<string, unknown>;
	multi_kills?: {
		duo?: number;
		triple?: number;
		quad?: number;
		ace?: number;
	};
	dmg?: Record<string, unknown>;
	flash?: {
		duration?: {
			self?: number;
			team?: number;
			enemy?: number;
		};
		total?: {
			self?: number;
			team?: number;
			enemy?: number;
		};
	};
}

/**
 * Transform legacy match list item to new format
 *
 * Converts a single match from the API's legacy format to our schema format.
 *
 * Key transformations:
 * - date: Unix timestamp → ISO 8601 string
 * - score: [a, b] array → score_team_a, score_team_b fields
 * - parsed → demo_parsed (rename)
 *
 * @param legacy - Match data from API in legacy format
 * @returns Match data in schema-compatible format
 */
export function transformMatchListItem(legacy: LegacyMatchListItem): MatchListItem {
	return {
		match_id: legacy.match_id, // Keep as string to preserve uint64 precision
		map: legacy.map || 'unknown', // Handle empty map names
		date: new Date(legacy.date * 1000).toISOString(), // Convert Unix timestamp to ISO string
		score_team_a: legacy.score[0],
		score_team_b: legacy.score[1],
		duration: legacy.duration,
		demo_parsed: legacy.parsed // Rename: parsed → demo_parsed
	};
}

/**
 * Transform legacy matches list response to new format
 *
 * IMPORTANT: The API returns a plain array, NOT an object with properties.
 * This function wraps the array and adds pagination metadata that we calculate ourselves.
 *
 * How pagination works:
 * 1. API returns plain array: [match1, match2, ...]
 * 2. We request limit + 1 to check if there are more matches
 * 3. If we get > limit matches, hasMore = true
 * 4. We extract timestamp from last match for next page: matches[length-1].date
 *
 * @param legacyMatches - Array of matches from API (already requested limit + 1)
 * @param hasMore - Whether there are more matches available (calculated by caller)
 * @param nextPageTime - Unix timestamp for next page (extracted from last match by caller)
 * @returns Wrapped response with pagination metadata
 */
export function transformMatchesListResponse(
	legacyMatches: LegacyMatchListItem[],
	hasMore: boolean = false,
	nextPageTime?: number
): MatchesListResponse {
	return {
		matches: legacyMatches.map(transformMatchListItem),
		has_more: hasMore,
		next_page_time: nextPageTime
	};
}

/**
 * Transform legacy player stats to new format
 */
export function transformPlayerStats(legacy: LegacyPlayerStats): MatchPlayer {
	// Extract Premier rating from rank object
	// API provides rank as { old: number, new: number }
	const rankOld =
		legacy.rank && typeof legacy.rank.old === 'number' ? (legacy.rank.old as number) : undefined;
	const rankNew =
		legacy.rank && typeof legacy.rank.new === 'number' ? (legacy.rank.new as number) : undefined;

	return {
		id: legacy.player.steamid64,
		name: legacy.player.name,
		avatar: `https://avatars.steamstatic.com/${legacy.player.avatar}_full.jpg`,
		team_id: legacy.team_id,
		kills: legacy.kills,
		deaths: legacy.deaths,
		assists: legacy.assists,
		headshot: legacy.headshot,
		mvp: legacy.mvp,
		score: legacy.score,
		// Premier rating (CS2: 0-30000)
		rank_old: rankOld,
		rank_new: rankNew,
		// Multi-kills: map legacy names to new format
		mk_2: legacy.multi_kills?.duo,
		mk_3: legacy.multi_kills?.triple,
		mk_4: legacy.multi_kills?.quad,
		mk_5: legacy.multi_kills?.ace,
		// Flash stats
		flash_duration_self: legacy.flash?.duration?.self,
		flash_duration_team: legacy.flash?.duration?.team,
		flash_duration_enemy: legacy.flash?.duration?.enemy,
		flash_total_self: legacy.flash?.total?.self,
		flash_total_team: legacy.flash?.total?.team,
		flash_total_enemy: legacy.flash?.total?.enemy
	};
}

/**
 * Transform legacy match detail to new format
 */
export function transformMatchDetail(legacy: LegacyMatchDetail): Match {
	return {
		match_id: legacy.match_id,
		share_code: legacy.share_code || undefined,
		map: legacy.map || 'unknown',
		date: new Date(legacy.date * 1000).toISOString(),
		score_team_a: legacy.score[0],
		score_team_b: legacy.score[1],
		duration: legacy.duration,
		match_result: legacy.match_result,
		max_rounds: legacy.max_rounds,
		demo_parsed: legacy.parsed,
		vac_present: legacy.vac,
		gameban_present: legacy.game_ban,
		players: legacy.stats?.map(transformPlayerStats)
	};
}

/**
 * Legacy player profile format from API
 */
export interface LegacyPlayerProfile {
	steamid64: string;
	name: string;
	avatar: string; // Hash, not full URL
	vac: boolean;
	vac_date: number; // Unix timestamp
	game_ban: boolean;
	game_ban_date: number; // Unix timestamp
	tracked: boolean;
	match_stats?: {
		win: number;
		loss: number;
	};
	matches?: Array<{
		match_id: string;
		map: string;
		date: number;
		score: [number, number];
		duration: number;
		match_result: number;
		max_rounds: number;
		parsed: boolean;
		vac: boolean;
		game_ban: boolean;
		stats: {
			team_id: number;
			kills: number;
			deaths: number;
			assists: number;
			headshot: number;
			mvp: number;
			score: number;
			rank: Record<string, unknown>;
			multi_kills?: Record<string, number>;
			dmg?: Record<string, unknown>;
		};
	}>;
}

/**
 * Transform legacy player profile to schema-compatible format
 */
export function transformPlayerProfile(legacy: LegacyPlayerProfile) {
	// Unix timestamp -62135596800 represents "no date" (year 0)
	const hasVacDate = legacy.vac_date && legacy.vac_date > 0;
	const hasGameBanDate = legacy.game_ban_date && legacy.game_ban_date > 0;

	return {
		id: legacy.steamid64,
		name: legacy.name,
		avatar: `https://avatars.steamstatic.com/${legacy.avatar}_full.jpg`,
		vac_count: legacy.vac ? 1 : 0,
		vac_date: hasVacDate ? new Date(legacy.vac_date * 1000).toISOString() : null,
		game_ban_count: legacy.game_ban ? 1 : 0,
		game_ban_date: hasGameBanDate ? new Date(legacy.game_ban_date * 1000).toISOString() : null,
		tracked: legacy.tracked,
		wins: legacy.match_stats?.win,
		losses: legacy.match_stats?.loss,
		matches: legacy.matches?.map((match) => {
			// Extract Premier rating from rank object
			const rankOld =
				match.stats.rank && typeof match.stats.rank.old === 'number'
					? (match.stats.rank.old as number)
					: undefined;
			const rankNew =
				match.stats.rank && typeof match.stats.rank.new === 'number'
					? (match.stats.rank.new as number)
					: undefined;

			return {
				match_id: match.match_id,
				map: match.map || 'unknown',
				date: new Date(match.date * 1000).toISOString(),
				score_team_a: match.score[0],
				score_team_b: match.score[1],
				duration: match.duration,
				match_result: match.match_result,
				max_rounds: match.max_rounds,
				demo_parsed: match.parsed,
				vac_present: match.vac,
				gameban_present: match.game_ban,
				stats: {
					id: legacy.steamid64,
					name: legacy.name,
					avatar: `https://avatars.steamstatic.com/${legacy.avatar}_full.jpg`,
					// Fix team_id: API returns 1/2, but schema expects min 2
					// Map: 1 -> 2 (Terrorists), 2 -> 3 (Counter-Terrorists)
					team_id:
						match.stats.team_id === 1 ? 2 : match.stats.team_id === 2 ? 3 : match.stats.team_id,
					kills: match.stats.kills,
					deaths: match.stats.deaths,
					assists: match.stats.assists,
					headshot: match.stats.headshot,
					mvp: match.stats.mvp,
					score: match.stats.score,
					// Premier rating (CS2: 0-30000)
					rank_old: rankOld,
					rank_new: rankNew,
					mk_2: match.stats.multi_kills?.duo,
					mk_3: match.stats.multi_kills?.triple,
					mk_4: match.stats.multi_kills?.quad,
					mk_5: match.stats.multi_kills?.ace
				}
			};
		})
	};
}