/**
 * Tekton Nakama Server Runtime Module
 * 
 * This module provides secure admin operations via RPC calls.
 * Deploy this to your Nakama server's runtime directory.
 */

// Initialize RPC endpoints
function InitModule(ctx, logger, nk, initializer) {
    // Admin RPCs
    initializer.registerRpc("admin_kick_player", rpcAdminKickPlayer);
    initializer.registerRpc("admin_ban_player", rpcAdminBanPlayer);
    initializer.registerRpc("admin_unban_player", rpcAdminUnbanPlayer);
    initializer.registerRpc("admin_get_ban_list", rpcAdminGetBanList);
    initializer.registerRpc("admin_get_server_stats", rpcAdminGetServerStats);
    initializer.registerRpc("admin_get_player_list", rpcAdminGetPlayerList);
    initializer.registerRpc("admin_end_match", rpcAdminEndMatch);
    initializer.registerRpc("admin_set_user_role", rpcAdminSetUserRole);

    // User management RPCs
    initializer.registerRpc("get_user_profile", rpcGetUserProfile);
    initializer.registerRpc("update_user_profile", rpcUpdateUserProfile);
    
    // Leaderboard RPCs
    initializer.registerRpc("get_leaderboard_stats", rpcGetLeaderboardStats);

    logger.info("Tekton admin module loaded");
}

// =============================================================================
// Authorization Helpers
// =============================================================================

var ADMIN_ROLES = ["admin", "moderator", "owner"];

function isAdmin(ctx, nk) {
    if (!ctx.userId) return false;

    try {
        var account = nk.accountGetId(ctx.userId);
        var metadata = JSON.parse(account.user.metadata || "{}");
        return ADMIN_ROLES.indexOf(metadata.role || "") !== -1;
    } catch (e) {
        return false;
    }
}

function isMatchHost(ctx, nk, matchId) {
    if (!ctx.userId || !matchId) return false;

    try {
        // Get match state to check host
        var match = nk.matchGet(matchId);
        if (!match) return false;

        // The first user to join (presence) is typically the host
        // This logic may need adjustment based on your match handler
        var state = JSON.parse(match.state || "{}");
        return state.hostUserId === ctx.userId;
    } catch (e) {
        return false;
    }
}

function requireAdmin(ctx, nk) {
    if (!isAdmin(ctx, nk)) {
        throw new Error("Admin privileges required");
    }
}

function requireAdminOrHost(ctx, nk, matchId) {
    if (!isAdmin(ctx, nk) && !isMatchHost(ctx, nk, matchId)) {
        throw new Error("Admin or host privileges required");
    }
}

// =============================================================================
// Admin RPCs
// =============================================================================

function rpcAdminKickPlayer(ctx, logger, nk, payload) {
    var request = JSON.parse(payload);

    requireAdminOrHost(ctx, nk, request.match_id);

    // Can't kick yourself
    if (request.user_id === ctx.userId) {
        throw new Error("Cannot kick yourself");
    }

    try {
        // Signal the match to kick the player
        nk.matchSignal(request.match_id, JSON.stringify({
            action: "kick",
            user_id: request.user_id,
            reason: request.reason || "Kicked by admin"
        }));

        logger.info("Player " + request.user_id + " kicked from match " + request.match_id + " by " + ctx.userId);

        return JSON.stringify({ success: true });
    } catch (e) {
        logger.error("Failed to kick player: " + e);
        throw new Error("Failed to kick player");
    }
}

function rpcAdminBanPlayer(ctx, logger, nk, payload) {
    var request = JSON.parse(payload);

    // Only full admins can ban (not just match hosts)
    requireAdmin(ctx, nk);

    if (request.user_id === ctx.userId) {
        throw new Error("Cannot ban yourself");
    }

    try {
        // Get target user's account
        var targetAccount = nk.accountGetId(request.user_id);
        var metadata = JSON.parse(targetAccount.user.metadata || "{}");

        // Don't allow banning other admins
        if (ADMIN_ROLES.indexOf(metadata.role || "") !== -1) {
            throw new Error("Cannot ban an admin");
        }

        // Set ban in metadata
        var banExpires = request.duration_hours && request.duration_hours > 0
            ? new Date(Date.now() + request.duration_hours * 60 * 60 * 1000).toISOString()
            : null;

        metadata.banned = true;
        metadata.ban_reason = request.reason || "Banned by admin";
        if (banExpires) {
            metadata.ban_expires = banExpires;
        }

        nk.accountUpdateId(request.user_id, null, null, null, null, null, null, JSON.stringify(metadata));

        // Also kick from current match if specified
        if (request.match_id) {
            nk.matchSignal(request.match_id, JSON.stringify({
                action: "kick",
                user_id: request.user_id,
                reason: "Banned: " + (request.reason || "")
            }));
        }

        // Store in ban list (for quick lookup)
        var banRecord = {
            user_id: request.user_id,
            username: targetAccount.user.username,
            banned_by: ctx.userId,
            banned_at: new Date().toISOString(),
            reason: request.reason,
            expires: banExpires
        };

        nk.storageWrite([{
            collection: "bans",
            key: request.user_id,
            userId: "00000000-0000-0000-0000-000000000000", // System-owned
            value: banRecord,
            permissionRead: 2, // Public read
            permissionWrite: 0 // No one can write (except server)
        }]);

        logger.warn("Player " + request.user_id + " banned by " + ctx.userId + ". Reason: " + request.reason);

        return JSON.stringify({ success: true, ban: banRecord });
    } catch (e) {
        logger.error("Failed to ban player: " + e);
        throw new Error("Failed to ban player: " + e);
    }
}

function rpcAdminUnbanPlayer(ctx, logger, nk, payload) {
    var request = JSON.parse(payload);

    requireAdmin(ctx, nk);

    try {
        // Get target user's account
        var targetAccount = nk.accountGetId(request.user_id);
        var metadata = JSON.parse(targetAccount.user.metadata || "{}");

        // Remove ban
        delete metadata.banned;
        delete metadata.ban_reason;
        delete metadata.ban_expires;

        nk.accountUpdateId(request.user_id, null, null, null, null, null, null, JSON.stringify(metadata));

        // Remove from ban list
        nk.storageDelete([{
            collection: "bans",
            key: request.user_id,
            userId: "00000000-0000-0000-0000-000000000000"
        }]);

        logger.info("Player " + request.user_id + " unbanned by " + ctx.userId);

        return JSON.stringify({ success: true });
    } catch (e) {
        logger.error("Failed to unban player: " + e);
        throw new Error("Failed to unban player");
    }
}

function rpcAdminGetBanList(ctx, logger, nk, payload) {
    requireAdmin(ctx, nk);

    try {
        var result = nk.storageList(
            "00000000-0000-0000-0000-000000000000",
            "bans",
            100,
            ""
        );

        var bans = result.objects ? result.objects.map(function(obj) { return obj.value; }) : [];

        return JSON.stringify({ bans: bans });
    } catch (e) {
        logger.error("Failed to get ban list: " + e);
        return JSON.stringify({ bans: [] });
    }
}

function rpcAdminGetServerStats(ctx, logger, nk, payload) {
    var request = JSON.parse(payload || "{}");

    if (request.match_id) {
        requireAdminOrHost(ctx, nk, request.match_id);
    } else {
        requireAdmin(ctx, nk);
    }

    try {
        // Get server-wide stats
        var matches = nk.matchList(100, true, null, null, null, null);
        var activeMatchCount = matches ? matches.length : 0;

        var totalPlayers = 0;
        if (matches) {
            for (var i = 0; i < matches.length; i++) {
                totalPlayers += matches[i].size || 0;
            }
        }

        var stats = {
            active_matches: activeMatchCount,
            total_players: totalPlayers,
            server_time: new Date().toISOString()
        };

        // If specific match requested, include match details
        if (request.match_id) {
            try {
                var match = nk.matchGet(request.match_id);
                if (match) {
                    stats.match = {
                        id: match.matchId,
                        size: match.size,
                        tick_rate: match.tickRate,
                        authoritative: match.authoritative
                    };
                }
            } catch (e) {
                // Match not found
            }
        }

        return JSON.stringify(stats);
    } catch (e) {
        logger.error("Failed to get server stats: " + e);
        throw new Error("Failed to get server stats");
    }
}

function rpcAdminGetPlayerList(ctx, logger, nk, payload) {
    var request = JSON.parse(payload);

    requireAdminOrHost(ctx, nk, request.match_id);

    try {
        var match = nk.matchGet(request.match_id);
        if (!match) {
            throw new Error("Match not found");
        }

        // Get player details
        var players = [];

        // Note: In actual implementation, you'd need to track presences
        // This is a simplified version - adjust based on your match handler

        return JSON.stringify({ players: players });
    } catch (e) {
        logger.error("Failed to get player list: " + e);
        throw new Error("Failed to get player list");
    }
}

function rpcAdminEndMatch(ctx, logger, nk, payload) {
    var request = JSON.parse(payload);

    requireAdminOrHost(ctx, nk, request.match_id);

    try {
        // Signal match to end
        nk.matchSignal(request.match_id, JSON.stringify({
            action: "end_match",
            reason: request.reason || "Ended by admin"
        }));

        logger.info("Match " + request.match_id + " ended by " + ctx.userId);

        return JSON.stringify({ success: true });
    } catch (e) {
        logger.error("Failed to end match: " + e);
        throw new Error("Failed to end match");
    }
}

function rpcAdminSetUserRole(ctx, logger, nk, payload) {
    var request = JSON.parse(payload);

    // Only owner/super-admin can set roles
    var callerAccount = nk.accountGetId(ctx.userId);
    var callerMetadata = JSON.parse(callerAccount.user.metadata || "{}");

    if (callerMetadata.role !== "owner") {
        throw new Error("Only owners can modify user roles");
    }

    var validRoles = ["player", "moderator", "admin"];
    if (validRoles.indexOf(request.role) === -1) {
        throw new Error("Invalid role");
    }

    try {
        var targetAccount = nk.accountGetId(request.user_id);
        var metadata = JSON.parse(targetAccount.user.metadata || "{}");

        metadata.role = request.role;

        nk.accountUpdateId(request.user_id, null, null, null, null, null, null, JSON.stringify(metadata));

        logger.info("User " + request.user_id + " role set to " + request.role + " by " + ctx.userId);

        return JSON.stringify({ success: true, role: request.role });
    } catch (e) {
        logger.error("Failed to set user role: " + e);
        throw new Error("Failed to set user role");
    }
}

// =============================================================================
// User Profile RPCs
// =============================================================================

function rpcGetUserProfile(ctx, logger, nk, payload) {
    var request = JSON.parse(payload || "{}");
    var targetUserId = request.user_id || ctx.userId;

    try {
        var account = nk.accountGetId(targetUserId);
        var metadata = JSON.parse(account.user.metadata || "{}");

        // Check if banned
        if (metadata.banned && targetUserId === ctx.userId) {
            // Check if ban expired
            if (metadata.ban_expires) {
                var expiresAt = new Date(metadata.ban_expires);
                if (expiresAt <= new Date()) {
                    // Ban expired, remove it
                    delete metadata.banned;
                    delete metadata.ban_reason;
                    delete metadata.ban_expires;
                    nk.accountUpdateId(targetUserId, null, null, null, null, null, null, JSON.stringify(metadata));
                } else {
                    throw new Error("Account banned until " + metadata.ban_expires + ". Reason: " + metadata.ban_reason);
                }
            } else {
                throw new Error("Account permanently banned. Reason: " + metadata.ban_reason);
            }
        }

        return JSON.stringify({
            user_id: account.user.id,
            username: account.user.username,
            display_name: account.user.displayName,
            avatar_url: account.user.avatarUrl,
            create_time: account.user.createTime,
            role: metadata.role || "player"
        });
    } catch (e) {
        throw e;
    }
}

function rpcUpdateUserProfile(ctx, logger, nk, payload) {
    if (!ctx.userId) {
        throw new Error("Not authenticated");
    }

    var request = JSON.parse(payload);

    try {
        nk.accountUpdateId(
            ctx.userId,
            null, // username
            request.display_name || null,
            null, // timezone
            null, // location
            null, // lang
            request.avatar_url || null,
            null // metadata
        );

        return JSON.stringify({ success: true });
    } catch (e) {
        logger.error("Failed to update profile: " + e);
        throw new Error("Failed to update profile");
    }
}

// =============================================================================
// Leaderboard RPCs
// =============================================================================

function rpcGetLeaderboardStats(ctx, logger, nk, payload) {
    try {
        // Query the "stats" collection to get all user stats
        // Warning: For a large production game this should be indexed using Nakama's actual Leaderboard system, 
        // but this works for listing all users' custom storage stats.
        var limit = 100;
        var result = nk.storageList(null, "stats", limit, "");
        
        var statsObjects = result.objects || [];
        var leaderboardData = [];
        
        for (var i = 0; i < statsObjects.length; i++) {
            var obj = statsObjects[i];
            try {
                var stats = JSON.parse(obj.value);
                var userId = obj.userId;
                
                // Get the user's profile to retrieve their display name
                var displayName = "Unknown";
                var avatarUrl = "";
                try {
                    var account = nk.accountGetId(userId);
                    displayName = account.user.displayName || account.user.username;
                    avatarUrl = account.user.avatarUrl;
                } catch (e) {
                    // Ignore if account fetch fails
                }
                
                leaderboardData.push({
                    user_id: userId,
                    display_name: displayName,
                    avatar_url: avatarUrl,
                    games_played: stats.games_played || 0,
                    games_won: stats.games_won || 0,
                    high_score: stats.high_score || 0
                });
            } catch (e) {
                logger.error("Error parsing stats for object: " + obj.key);
            }
        }
        
        return JSON.stringify({ leaderboard: leaderboardData });
    } catch (e) {
        logger.error("Failed to get leaderboard stats: " + e);
        throw new Error("Failed to get leaderboard stats");
    }
}

// Before login hook to check ban status
function beforeAuthenticateEmail(ctx, logger, nk, data) {
    // Can't check ban before auth, so we check in afterAuthenticate
    return data;
}