import * as Convict from "convict";
import { isSchemaObject, primitiveConstructors } from "./utils";

const defaultOrder = ['name', 'default', 'arg', 'env', 'format', 'nullable', 'sensitive', 'doc'];

export function renderField(fieldName: keyof Convict.SchemaObj<unknown> | 'name', name: string, obj: Convict.SchemaObj<unknown>): string {
    switch (fieldName) {
        case 'arg':
            return `${obj.arg ?? '-'}`;
        case 'doc':
            return `${obj.doc ?? '-'}`;
        case 'default':
            return `${JSON.stringify(obj.default)}`;
        case 'format':
            return renderFormat(obj);
        case 'nullable':
            return renderNullable(obj);
        case 'sensitive':
            return renderSensitive(obj);
        case 'env':
            return `${obj.env ?? '-'}`;
        case 'name':
            return name;
        default:
            return `unknown`
    }
}

export function renderDoc<T = any>(schema: Convict.Schema<T>, order: string[] = defaultOrder): string {
    const header = renderHeader(order);
    return renderSchema(schema, "", order, header);
}

export function renderSchemaObj(
    name: string,
    obj: Convict.SchemaObj<unknown>,
    order: string[] = defaultOrder
): string {
    return `|${order.map(fieldName => renderField(fieldName, name, obj)).join('|')}|\n`
}

export function renderSchema<T>(
    schema: Convict.Schema<T>,
    namePrefix: string = "",
    order: string[] = defaultOrder,
    render = ""
): string {
    let res = render;

    for (let [key, value] of Object.entries(schema)) {
        if (isSchemaObject(value as any)) {
            res += renderSchemaObj(
                `${namePrefix ? namePrefix + "." + key : key}`,
                value as any,
                order
            );
        } else {
            res += renderSchema(value as any, key, order);
        }
    }
    return res;
}

function renderHeader(order: string[] = defaultOrder): string {
    return `
# Configuration Parameters

|${order.join("|")}|
|${order.map(s => s.replaceAll(/./g, "-")).join("|")}|\n`;
}

export function renderNullable(obj: Convict.SchemaObj<unknown>): string {
    return `${obj.nullable ?? false}`;
}

export function renderSensitive(obj: Convict.SchemaObj<unknown>): string {
    return `${obj.sensitive ?? false}`;
}

export function renderFormat(obj: Convict.SchemaObj<unknown>): string {
    if (Array.isArray(obj.format)) {
        return obj.format.join(" &#124; ");
    }

    if (primitiveConstructors.includes(obj.format as any)) {
        return `${(obj.format as Function).name}`;
    }

    switch (typeof obj.format) {
        case "function":
            return `${(obj as any).format.name ?? "unknown format function"}`;
        case "string":
            return `${obj.format}`;
        case undefined:
            return "any";
        default:
            return "unknown";
    }
}