class ErrorHandler {
    constructor(options) {
        if (!options) throw new Error("Options not provided");
        if (!options.url) throw new Error("URL is required");
        if (!options.apikey) throw new Error("API key is required");

        this.url = options.url;
        this.apikey = options.apikey;
        this.catchError();
    }

    getSourceCode(lineNumber) {
        return this.getInlineSourceCode(lineNumber) || this.getFullSourceWithHighlight(lineNumber);
    }

    getInlineSourceCode(lineNumber) {
        const scripts = document.querySelectorAll('script');
        for (let script of scripts) {
            if (!script.src) { 
                const scriptLines = script.textContent.split("\n");
                const scriptPosition = this.getErrorPosition(script);
                if (lineNumber >= scriptPosition.startLine && lineNumber <= scriptPosition.endLine) {
                    return this.highlightSource(scriptLines, lineNumber - scriptPosition.startLine);
                }
            }
        }
        return null;
    }

    getFullSourceWithHighlight(lineNumber) {
        const lines = document.documentElement.outerHTML.split("\n");
        return this.highlightSource(lines, lineNumber - 1);
    }

    highlightSource(lines, lineNumber) {
        const start = Math.max(lineNumber - 2, 0);
        const end = Math.min(lineNumber + 2, lines.length - 1);
        lines[lineNumber] = '>> ' + lines[lineNumber] + ' <<'; 
        return lines.slice(start, end + 1).join("\n");
    }

    getErrorPosition(script) {
        let totalLines = 0;
        let element = script.previousElementSibling;
        while (element) {
            totalLines += (element.outerHTML || element.textContent).split("\n").length;
            element = element.previousElementSibling;
        }
        return {
            startLine: totalLines + 1,
            endLine: totalLines + script.textContent.split("\n").length
        };
    }

    catchError() {
        window.onerror = (message, url, lineNumber, column, error) => {
            this.reportError(message, url, lineNumber, column, error.stack, 'JavaScript Error');
            return false;
        };

        window.addEventListener('unhandledrejection', event => {
            this.reportError(event.reason.toString(), document.location.href, 0, 0, event.reason.stack, 'Promise Rejection');
        });
    }

    reportError(message, url, lineNumber, column, stack, type = 'JavaScript Error') {
        fetch(this.url ? `${location.protocol}//${this.url}/${this.apikey}` : window.location.href, {
            method: "post",
            headers: {
                'Accept': "application/json",
                'Content-Type': "application/json"
            },
            body: JSON.stringify({
                type,
                message,
                url,
                lineNumber,
                column,
                stack,
                location: window.location.href,
                source: this.getSourceCode(lineNumber)
            })
        }).then(response => response.json()).then(console.info);
    }
}