using System;
using System.Collections.Generic;
using System.Linq;

namespace Socer;

public sealed record PlatformAchievementDefinition(string Id,string EnglishTitle,string RussianTitle,
    string EnglishDescription,string RussianDescription,int Score);

// Pure eligibility rules. The platform adapter decides whether the current
// session may submit anything; inspecting a career never changes it or pays prizes.
public static class PlatformAchievementRules
{
    const int CatalogVersion=2;
    static int loadedCatalogVersion;
    static IReadOnlyList<PlatformAchievementDefinition> definitions;
    // Hotload preserves static initializers. Rebuild the catalogue when its
    // version changes so an already-open editor sees the same rules as a fresh client.
    public static IReadOnlyList<PlatformAchievementDefinition> All
    {
        get
        {
            if(definitions==null || loadedCatalogVersion!=CatalogVersion)
            {definitions=CreateDefinitions();loadedCatalogVersion=CatalogVersion;}
            return definitions;
        }
    }
    static IReadOnlyList<PlatformAchievementDefinition> CreateDefinitions()=>Array.AsReadOnly(new PlatformAchievementDefinition[]
    {
        new PlatformAchievementDefinition("first-match","First whistle","Первый свисток","Finish a competitive career match.","Завершите официальный матч карьеры.",5),
        new("first-win","Off the mark","Первая победа","Win a competitive career match, including a penalty shootout.","Выиграйте официальный матч карьеры, в том числе по пенальти.",10),
        new("clean-sheet-win","Clean sheet","Сухая победа","Win a competitive career match without conceding, before a penalty shootout.","Выиграйте официальный матч карьеры без пропущенных голов до серии пенальти.",20),
        new("big-win","Clear advantage","Уверенная победа","Win a competitive career match by at least three goals.","Выиграйте официальный матч карьеры с разницей не менее трёх голов.",20),
        new("ten-wins","Winning habit","Привычка побеждать","Win 10 competitive matches in one career.","Выиграйте 10 официальных матчей в одной карьере.",30),
        new("century-matches","One hundred matches","Сотня матчей","Finish 100 competitive matches in one career.","Завершите 100 официальных матчей в одной карьере.",75),
        new("legendary-pull","A legend joins","Легенда в команде","Obtain a legendary player from a pack.","Получите легендарного игрока из пака.",75),
        new("reach-second-league","Second League","Вторая лига","Reach the Second League in your career.","Доберитесь до Второй лиги в карьере.",30),
        new("reach-first-league","First League","Первая лига","Reach the First League in your career.","Доберитесь до Первой лиги в карьере.",50),
        new("reach-national-league","National League","Национальная лига","Reach the National League in your career.","Доберитесь до Национальной лиги в карьере.",75),
        new("reach-premier-league","Premier League","Премьер-лига","Reach the Premier League in your career.","Доберитесь до Премьер-лиги в карьере.",100),
        new("first-league-title","First league title","Первое чемпионство","Win any career league.","Выиграйте любую лигу в карьере.",50),
        new("cup-winner","Cup winner","Обладатель кубка","Win a career cup.","Выиграйте кубок в карьере.",50),
        new("premier-champion","Premier champion","Чемпион Премьер-лиги","Win the Premier League.","Выиграйте Премьер-лигу.",100),
        new("unbeaten-champion","Unbeaten champion","Непобеждённый чемпион","Win the Premier League without losing a league match that season.","Выиграйте Премьер-лигу без поражений в лиге за сезон.",100),
        new("domestic-double","Domestic double","Золотой дубль","Win the Premier League and a cup in the same season.","Выиграйте Премьер-лигу и кубок в одном сезоне.",100),
        new("champions-cup","The final trophy","Главный трофей","Win the Champions Cup and complete the career campaign.","Выиграйте финальный Champions Cup и пройдите карьеру.",100)
    });

    static readonly string[] TitleIds={"first-league-title","cup-winner","premier-champion","unbeaten-champion","domestic-double"};
    static readonly string[] LeagueIds={"reach-second-league","reach-first-league","reach-national-league","reach-premier-league"};
    readonly record struct Result(int OwnGoals,int OtherGoals,bool Penalties,int OwnPenalties,int OtherPenalties)
    {
        public bool Won=>OwnGoals>OtherGoals || Penalties && OwnGoals==OtherGoals && OwnPenalties>OtherPenalties;
    }

    public static IReadOnlyCollection<string> Earned(ClubCareer career)
    {
        if(career==null)return Array.Empty<string>();
        var earned=new HashSet<string>(StringComparer.Ordinal);
        var results=MatchResults(career).Values.ToArray();
        int wins=results.Count(r=>r.Won);
        if(results.Length>0)earned.Add("first-match");
        if(wins>0)earned.Add("first-win");
        if(wins>=10)earned.Add("ten-wins");
        if(results.Length>=100)earned.Add("century-matches");
        if(career.LegendaryPackObtained)earned.Add("legendary-pull");
        if(career.CareerWon)earned.Add("champions-cup");
        if(results.Any(r=>!r.Penalties && r.OwnGoals>0 && r.OtherGoals==0))earned.Add("clean-sheet-win");
        if(results.Any(r=>r.OwnGoals-r.OtherGoals>=3))earned.Add("big-win");

        var seasons=(career.LeagueHistory??new()).Where(r=>r!=null && r.Season>0 && r.Season<=career.Season &&
            r.Division is >=1 and <=5 && r.Place is >=1 and <=8 && r.Played>=14).ToArray();
        int reached=career.Division is >=1 and <=5?career.Division:1;
        foreach(var season in seasons)
        {
            reached=Math.Max(reached,season.Division);
            // A completed current table proves its own league. Only a prior
            // season proves that the next-season transition already happened.
            if(season.Season<career.Season && season.Place<=2)reached=Math.Max(reached,Math.Min(5,season.Division+1));
        }
        for(int division=2;division<=reached;division++)earned.Add(LeagueIds[division-2]);

        var cups=career.CupResults.Where(c=>c!=null && c.Season>0 && c.Season<=career.Season &&
            c.Round==3 && c.PlaceFrom==1 && c.PlaceTo==1).ToArray();
        if(cups.Length>0)earned.Add("cup-winner");
        foreach(var season in seasons.Where(s=>s.Place==1))
        {
            earned.Add("first-league-title");
            if(season.Division!=5)continue;
            earned.Add("premier-champion");
            // A zero default alone cannot prove an undefeated old season.
            if(season.Losses==0 && season.Wins+season.Draws==season.Played)earned.Add("unbeaten-champion");
            if(cups.Any(c=>c.Season==season.Season))earned.Add("domestic-double");
        }
        // Existing club honours were awarded by the career settlement resolver.
        // Preserve them across legacy saves without re-running reward resolution.
        foreach(var achievement in career.Achievements??new())
            if(achievement!=null && achievement.EarnedSeason>0 && achievement.EarnedSeason<=career.Season && TitleIds.Contains(achievement.Id))
                earned.Add(achievement.Id);
        return All.Where(d=>earned.Contains(d.Id)).Select(d=>d.Id).ToArray();
    }

    static Dictionary<string,Result> MatchResults(ClubCareer career)
    {
        var results=new Dictionary<string,Result>(StringComparer.Ordinal);
        foreach(var report in career.MatchHistory??new())
        {
            if(report==null || report.Season<=0 || report.Season>career.Season || report.OwnSide is <0 or >1)continue;
            string key=CanonicalKey(report);
            if(key==null || !ValidScore(report.HomeGoals,report.AwayGoals,report.Penalties,report.HomePenalties,report.AwayPenalties,report.Cup))continue;
            results.TryAdd(key,report.OwnSide==0
                ?new(report.HomeGoals,report.AwayGoals,report.Penalties,report.HomePenalties,report.AwayPenalties)
                :new(report.AwayGoals,report.HomeGoals,report.Penalties,report.AwayPenalties,report.HomePenalties));
        }
        void AddFixture(ClubFixture fixture,string cupId=null)
        {
            if(fixture==null || !fixture.Played || fixture.Id<0 || (fixture.Home==0)==(fixture.Away==0) ||
                !ValidScore(fixture.HomeGoals,fixture.AwayGoals,fixture.Penalties,fixture.HomePenalties,fixture.AwayPenalties,cupId!=null))return;
            string key=cupId==null?$"{career.Season}:league:{fixture.Id}":$"{career.Season}:cup:{cupId}:{fixture.Id}";
            results.TryAdd(key,fixture.Home==0
                ?new(fixture.HomeGoals,fixture.AwayGoals,fixture.Penalties,fixture.HomePenalties,fixture.AwayPenalties)
                :new(fixture.AwayGoals,fixture.HomeGoals,fixture.Penalties,fixture.AwayPenalties,fixture.HomePenalties));
        }
        foreach(var fixture in career.League??new())AddFixture(fixture);
        foreach(var cup in career.Tournaments??new())
            if(cup!=null && !string.IsNullOrWhiteSpace(cup.Id))
                foreach(var fixture in cup.Games??new())AddFixture(fixture,cup.Id);
        return results;
    }
    static bool ValidScore(int home,int away,bool penalties,int homePenalties,int awayPenalties,bool cup)=>home>=0 && away>=0 &&
        (!penalties || cup && home==away && homePenalties>=0 && awayPenalties>=0 && homePenalties!=awayPenalties);
    static string CanonicalKey(ArchivedClubMatch report)
    {
        string[] parts=(report.Key??"").Split(':');
        if(parts.Length is <3 or >4 || !int.TryParse(parts[0],out int season) || season!=report.Season ||
            !int.TryParse(parts[^1],out int fixture) || fixture<0)return null;
        if(!report.Cup)return parts.Length==3 && parts[1]=="league"?$"{season}:league:{fixture}":null;
        if(parts.Length==4)return parts[1]=="cup" && !string.IsNullOrWhiteSpace(parts[2])?$"{season}:cup:{parts[2]}:{fixture}":null;
        return !string.IsNullOrWhiteSpace(parts[1])?$"{season}:cup:{parts[1]}:{fixture}":null;
    }
}