import { and, eq } from 'drizzle-orm';
import * as z from 'zod';
import { settings } from '~~/drizzle/schema';
import { db } from '~~/server/lib/db';

const appearanceSchema = z.object({
    colorScheme: z.enum(['light', 'dark', 'system']).optional(),
    accent: z.string().optional(),
    neutral: z.string().optional(),
    hinting: z.number().min(0).max(100).optional(),
    fontSize: z.string().optional(),
});

const updateSettingsSchema = z.object({
    systemAssistants: z.object({
        rename: z.object({
            enabled: z.boolean(),
            modelId: z.string().nullable(),
        }).partial().optional(),
    }).optional(),
    appearance: appearanceSchema.optional(),
});

export default defineEventHandler(async (event) => {
    await protectRoute(event);
    const userId = event.context.user!.id as string;

    const body = await readBody(event);
    const parseResult = updateSettingsSchema.safeParse(body);

    if (!parseResult.success) {
        throw createError({
            statusCode: 400,
            message: parseResult.error.issues[0]!.message,
        });
    }

    const updates = parseResult.data;
    const existing = await db.query.settings.findFirst({
        where: { userId },
    });

    if (!existing) {
        throw createError({
            statusCode: 404,
            statusMessage: 'Settings not found',
        });
    }

    const existingId: string = existing.id;

    const mergeAppearance = (
        existingAppearance: Record<string, unknown> | null,
        incoming: typeof updates.appearance,
    ): Record<string, unknown> => {
        const base = existingAppearance || {};
        if (!incoming) return base;
        return { ...base, ...incoming };
    };

    const newSystemAssistants = {
        rename: {
            enabled: updates.systemAssistants?.rename?.enabled ?? existing.systemAssistants.rename?.enabled ?? false,
            modelId: updates.systemAssistants?.rename?.modelId !== undefined
                ? updates.systemAssistants.rename.modelId
                : existing.systemAssistants.rename?.modelId ?? null,
        },
    };

    const newAppearance = mergeAppearance(
        existing.appearance as Record<string, unknown> | null,
        updates.appearance,
    );
    await db.update(settings)
        .set({
            appearance: newAppearance,
            systemAssistants: newSystemAssistants,
        })
        .where(and(eq(settings.id, existingId)));

    const updated = await db.select()
        .from(settings)
        .where(and(eq(settings.id, existingId)))
        .limit(1);

    return updated[0];
});