using GameList.Contracts;
using GameList.Data;
using GameList.Domain;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace GameList.Endpoints;

public static class SuggestEndpoints
{
    public static void MapSuggestEndpoints(this IEndpointRouteBuilder app)
    {
        app.MapGet("/api/suggestions/mine", async (HttpContext ctx, AppDbContext db) =>
        {
            var player = await EndpointHelpers.GetAuthenticatedPlayer(ctx, db);
            if (player is null) return Results.Unauthorized();
            var mine = await db.Suggestions.AsNoTracking()
                .Where(s => s.PlayerId == player.Id)
                .Select(s => new
                {
                    s.Id,
                    s.PlayerId,
                    s.Name,
                    s.Genre,
                    s.Description,
                    s.ScreenshotUrl,
                    s.YoutubeUrl,
                    s.GameUrl,
                    s.CreatedAt,
                    s.MinPlayers,
                    s.MaxPlayers,
                    s.ParentSuggestionId
                })
                .ToListAsync();

            var ordered = mine
                .OrderBy(s => s.CreatedAt)
                .Select(s => new SuggestionDto(s.Id, s.Name, s.Genre, s.Description, s.ScreenshotUrl, s.YoutubeUrl, s.GameUrl, s.MinPlayers, s.MaxPlayers, s.ParentSuggestionId));

            return Results.Ok(ordered);
        });

        app.MapPost("/api/suggestions", async ([FromBody] SuggestionRequest request, HttpContext ctx, AppDbContext db, IHttpClientFactory http) =>
        {
            if (string.IsNullOrWhiteSpace(request.Name) || request.Name.Length > 100)
            {
                return Results.BadRequest(new { error = "Name is required and must be <= 100 characters." });
            }

            if (!EndpointHelpers.IsValidImageUrl(request.ScreenshotUrl))
            {
                return Results.BadRequest(new { error = "Screenshot URL must be http(s) and end with an image file extension." });
            }
            if (!await EndpointHelpers.IsReachableImageAsync(request.ScreenshotUrl, http))
            {
                return Results.BadRequest(new { error = "Screenshot URL could not be validated as an image." });
            }

            if (!ValidatePlayers(request.MinPlayers, request.MaxPlayers, out var playersError))
                return Results.BadRequest(new { error = playersError });

            var player = await EndpointHelpers.GetAuthenticatedPlayer(ctx, db);
            if (player is null) return Results.Unauthorized();
            var phase = await EndpointHelpers.GetPhase(db, player.Id);
            if (phase != Phase.Suggest)
                return EndpointHelpers.PhaseMismatch(Phase.Suggest, phase);

            if (string.IsNullOrWhiteSpace(player.DisplayName))
            {
                return Results.BadRequest(new { error = "Set a display name before submitting suggestions." });
            }

            var existingCount = await db.Suggestions.CountAsync(s => s.PlayerId == player.Id);
            if (existingCount >= 5)
            {
                return Results.BadRequest(new { error = "You have reached the 5 suggestion limit." });
            }

            var suggestion = new Suggestion
            {
                PlayerId = player.Id,
                Name = request.Name.Trim(),
                Genre = EndpointHelpers.TrimTo(request.Genre, 50),
                Description = EndpointHelpers.TrimTo(request.Description, 500),
                ScreenshotUrl = EndpointHelpers.TrimTo(request.ScreenshotUrl, 2048),
                YoutubeUrl = EndpointHelpers.TrimTo(request.YoutubeUrl, 2048),
                GameUrl = EndpointHelpers.TrimTo(request.GameUrl, 2048),
                MinPlayers = request.MinPlayers,
                MaxPlayers = request.MaxPlayers
            };

            db.Suggestions.Add(suggestion);
            await db.SaveChangesAsync();

            return Results.Created($"/api/suggestions/{suggestion.Id}", new { suggestion.Id });
        });

        app.MapDelete("/api/suggestions/{id:int}", async (int id, HttpContext ctx, AppDbContext db, IConfiguration config) =>
        {
            var player = await EndpointHelpers.GetAuthenticatedPlayer(ctx, db);
            if (player is null) return Results.Unauthorized();
            var isAdmin = await EndpointHelpers.IsAdmin(ctx, db, config);

            var phase = await EndpointHelpers.GetPhase(db, player.Id);
            if (!isAdmin && phase != Phase.Suggest)
                return Results.BadRequest(new { error = "Suggestions are frozen; you can no longer delete them." });

            var suggestion = isAdmin
                ? await db.Suggestions.FirstOrDefaultAsync(s => s.Id == id)
                : await db.Suggestions.FirstOrDefaultAsync(s => s.Id == id && s.PlayerId == player.Id);
            if (suggestion == null)
                return Results.NotFound(new { error = "Suggestion not found." });

            db.Suggestions.Remove(suggestion);
            await db.SaveChangesAsync();
            return Results.NoContent();
        });

        app.MapPut("/api/suggestions/{id:int}", async (int id, [FromBody] SuggestionRequest request, HttpContext ctx, AppDbContext db, IConfiguration config, IHttpClientFactory http) =>
        {
            var player = await EndpointHelpers.GetAuthenticatedPlayer(ctx, db);
            var isAdmin = await EndpointHelpers.IsAdmin(ctx, db, config);

            if (!isAdmin)
            {
                if (player is null) return Results.Unauthorized();

                var phase = await EndpointHelpers.GetPhase(db, player.Id);
                // Non-admins can edit optional fields after Suggest, but not the name
            }

            if (string.IsNullOrWhiteSpace(request.Name) || request.Name.Length > 100)
            {
                return Results.BadRequest(new { error = "Name is required and must be <= 100 characters." });
            }

            if (!EndpointHelpers.IsValidImageUrl(request.ScreenshotUrl))
            {
                return Results.BadRequest(new { error = "Screenshot URL must be http(s) and end with an image file extension." });
            }
            if (!await EndpointHelpers.IsReachableImageAsync(request.ScreenshotUrl, http))
            {
                return Results.BadRequest(new { error = "Screenshot URL could not be validated as an image." });
            }

            if (!ValidatePlayers(request.MinPlayers, request.MaxPlayers, out var playersError))
                return Results.BadRequest(new { error = playersError });

            var suggestion = await db.Suggestions.FirstOrDefaultAsync(s => s.Id == id);
            if (suggestion == null) return Results.NotFound(new { error = "Suggestion not found." });

            if (!isAdmin)
            {
                if (suggestion.PlayerId != player!.Id)
                    return Results.Unauthorized();
            }

            var isSuggestPhase = isAdmin ? true : await EndpointHelpers.GetPhase(db, player?.Id ?? Guid.Empty) == Phase.Suggest;
            if (isSuggestPhase || isAdmin)
            {
                suggestion.Name = request.Name.Trim();
            }
            suggestion.Genre = EndpointHelpers.TrimTo(request.Genre, 50);
            suggestion.Description = EndpointHelpers.TrimTo(request.Description, 500);
            suggestion.ScreenshotUrl = EndpointHelpers.TrimTo(request.ScreenshotUrl, 2048);
            suggestion.YoutubeUrl = EndpointHelpers.TrimTo(request.YoutubeUrl, 2048);
            suggestion.GameUrl = EndpointHelpers.TrimTo(request.GameUrl, 2048);
            suggestion.MinPlayers = request.MinPlayers;
            suggestion.MaxPlayers = request.MaxPlayers;

            await db.SaveChangesAsync();

            return Results.Ok(new
            {
                suggestion.Id,
                suggestion.Name,
                suggestion.Genre,
                suggestion.Description,
                suggestion.ScreenshotUrl,
                suggestion.YoutubeUrl,
                suggestion.GameUrl,
                suggestion.MinPlayers,
                suggestion.MaxPlayers
            });
        });

        app.MapGet("/api/suggestions/all", async (HttpContext ctx, AppDbContext db) =>
        {
            var player = await EndpointHelpers.GetAuthenticatedPlayer(ctx, db);
            if (player is null) return Results.Unauthorized();
            var phase = await EndpointHelpers.GetPhase(db, player.Id);
            if (phase < Phase.Vote)
                return EndpointHelpers.PhaseMismatch(Phase.Vote, phase);

            var all = await db.Suggestions.AsNoTracking()
                .Include(s => s.Player)
                .Select(s => new
                {
                    s.Id,
                    s.PlayerId,
                    s.Name,
                    s.Genre,
                    s.Description,
                    s.ScreenshotUrl,
                    s.YoutubeUrl,
                    s.GameUrl,
                    s.MinPlayers,
                    s.MaxPlayers,
                    Author = s.Player!.DisplayName,
                    s.CreatedAt,
                    s.ParentSuggestionId
                })
                .ToListAsync();

            var rootIndex = EndpointHelpers.BuildLinkRoots(all.Select(s => (s.Id, s.ParentSuggestionId)));
            var nameLookup = all.ToDictionary(s => s.Id, s => s.Name);

            var ordered = all
                .OrderBy(s => s.CreatedAt)
                .Select(s =>
                {
                    var linkedIds = EndpointHelpers.LinkedIdsFor(s.Id, rootIndex)
                        .Where(id => id != s.Id)
                        .ToList();

                    return new
                    {
                        s.Id,
                        s.PlayerId,
                        s.Name,
                        s.Genre,
                        s.Description,
                        s.ScreenshotUrl,
                        s.YoutubeUrl,
                        s.GameUrl,
                        s.MinPlayers,
                        s.MaxPlayers,
                        s.Author,
                        s.ParentSuggestionId,
                        LinkedIds = linkedIds,
                        LinkedTitles = linkedIds
                            .Where(id => nameLookup.ContainsKey(id))
                            .Select(id => nameLookup[id])
                            .ToList()
                    };
                });

            return Results.Ok(ordered);
        });
    }

    private static bool ValidatePlayers(int? minPlayers, int? maxPlayers, out string? error)
    {
        error = null;
        if (minPlayers is null && maxPlayers is null) return true;

        if (minPlayers is not null && (minPlayers < 1 || minPlayers > 32))
        {
            error = "Min players must be between 1 and 32.";
            return false;
        }

        if (maxPlayers is not null && (maxPlayers < 1 || maxPlayers > 32))
        {
            error = "Max players must be between 1 and 32.";
            return false;
        }

        if (minPlayers is null || maxPlayers is null)
        {
            error = "Provide both min and max players.";
            return false;
        }

        if (minPlayers > maxPlayers)
        {
            error = "Min players cannot exceed max players.";
            return false;
        }

        return true;
    }
}