import { normalize } from "path";
import { Node, TypeNode } from 'typescript';

export class ResolverError extends Error {
    constructor(message?: string, node?: Node | TypeNode, onlyCurrent = false) {
        super(message);
        
        if (node) {
            this.message = `${message!}\n${prettyLocationOfNode(node)}\n${prettyTroubleCause(node, onlyCurrent)}`;
        }
    }
}

export function prettyLocationOfNode(node: Node | TypeNode) {
    const sourceFile = node.getSourceFile();
    const token = node.getFirstToken() || node.parent.getFirstToken();
    const start = token ? `:${sourceFile.getLineAndCharacterOfPosition(token.getStart()).line + 1}` : '';
    const end = token ? `:${sourceFile.getLineAndCharacterOfPosition(token.getEnd()).line + 1}` : '';
    const normalizedPath = normalize(`${sourceFile.fileName}${start}${end}`);
    return `At: ${normalizedPath}.`;
}

export function prettyTroubleCause(node: Node | TypeNode, onlyCurrent = false) {
    let name: string;
    if (onlyCurrent || !node.parent) {
        name = node.pos !== -1 ? node.getText() : (node as any).name.text;
    } else {
        name = node.parent.pos !== -1 ? node.parent.getText() : (node as any).parent.name.text;
    }
    return `This was caused by '${name}'`;
}