/**
 * Title:           GRIDS Basic Page Script
 * Description:     Page Script for /grids-basic.html
 * Author:          Peter Harpending <peterharpending@qpq.swiss>
 * Date:            2025-12-29
 * Last-Updated:    2025-12-29
 *
 * @module
 */

main();


/**
 * Runs on page load
 */
async function
main
    ()
{
    let n_input    = document.getElementById('grids-n')      as HTMLInputElement;
    let r_input    = document.getElementById('grids-r')      as HTMLInputElement;
    let a_input    = document.getElementById('grids-a')      as HTMLInputElement;
    let p_input    = document.getElementById('grids-p')      as HTMLInputElement;
    let submit_btn = document.getElementById('grids-submit') as HTMLInputElement;

    let grids_url_elt = document.getElementById('grids-url') as HTMLTextAreaElement;
    let grids_png_elt = document.getElementById('grids-png') as HTMLImageElement;

    // Page initialization
    submit_btn.addEventListener(
        'click',
        async function(e) {
            await on_submit(n_input, r_input, a_input, p_input, grids_url_elt, grids_png_elt)
        }
    );

    // enable buttons
    submit_btn.disabled = false;
}

async function
on_submit
    (n_input       : HTMLInputElement,
     r_input       : HTMLInputElement,
     a_input       : HTMLInputElement,
     p_input       : HTMLInputElement,
     grids_url_elt : HTMLTextAreaElement,
     grids_png_elt : HTMLImageElement)
    : Promise<void>
{
    // pull out values
    let network_id : string = n_input.value;
    let recipient  : string = r_input.value;
    let amount     : number = parseInt(a_input.value);
    let payload    : string = p_input.value;

    let result: Safe<GridsResult> = await grids_request(network_id, recipient, amount, payload);

    // show url field and png
    if (result.ok) {
        let url        : string = result.result.url;
        let png_base64 : string = result.result.png_base64;

        let src_prefix : string = 'data:image/png;base64,'

        let src = src_prefix + png_base64;

        grids_url_elt.innerText = url;
        grids_png_elt.src       = src;

        grids_url_elt.hidden = false;
        grids_png_elt.hidden = false;
    }
    else {
        alert('ERROR: ' + result.error);
    }
}


type Safe<t> = {ok: true,  result: t}
             | {ok: false, error: string};

type GridsResult = {url       : string,
                    png_base64: string};

/**
 * gets the grids url
 */
async function
grids_request
    (net_id    : string,
     recipient : string,
     amount    : number,
     payload   : string)
    : Promise<Safe<GridsResult>>
{
    // format for network transmission
    let obj      : object = {'network_id' : net_id,
                             'recipient'  : recipient,
                             'amount'     : amount,
                             'payload'    : payload};
    let obj_text : string = JSON.stringify(obj, undefined, 4);


    let url = '/grids-spend';
    let req_options  = {method:  'POST',
                        headers: {'content-type': 'application/json'},
                        body:    obj_text};


    let result: Safe<GridsResult> =
            {ok    : false,
             error : 'IT DO BE LIKE THAT MISTA STANCIL'};

    try {
        let response : Response = await fetch(url, req_options);
        if (response.ok)
            result = await response.json() as Safe<GridsResult>;
        else {
            console.log('bad http response:', response);
            result = {ok: false, error: 'BAD HTTP RESPONSE'};
        }
    }
    catch (x: any) {
        console.log('network error:', x);
        result = {ok: false, error: 'NETWORK ERROR'};
    }

    return result;
}