var gui = require('gui');
var fs = require('fs');

    var rh = 14;
    var sp = 4;
    var y = sp;

function getAccounts(data) {
    const resultData = [];
    for (let i = 0; i < data.length; i++) {
        resultData.push(data[i].name);
    }
    return resultData
}

function toListViewEntries(entries, visibleCols) {
    let cols = visibleCols;
    return entries.map(e => {
        const amount = parseFloat(e.amount);
        const subject = ("" + e.subject).substr(0, cols - 20).padEnd(cols - 20, ' ');
        const sum = ((amount >= 0 ? "+" : "") + amount.toFixed(2)).substr(0, 10).padStart(10, ' ');
        const d = new Date(e.date);
        const date = d.getDay().toString().padStart(2, '0') + "-" + (d.getMonth() + 1).toString().padStart(2, '0') + "-" + d.getFullYear();
        let s = (date.substr(0, 10)) + " " + subject + " " + sum;
        return s;
    });
}

function getSummation(entries) {
    return entries.reduce((sum, e) => sum + parseFloat(e.amount), 0);
}

function toDateByComponents(s) {
    const parts = s.split("-");
    if (parts.length !== 3) return null;
    const day = parseInt(parts[0]);
    const month = parseInt(parts[1]) - 1;
    const year = parseInt(parts[2]);
    if (isNaN(day) || isNaN(month) || isNaN(year)) return null;
    return new Date(year, month, day).getTime();
}

function subWindow(data) {
    let gadgets = [];
    let removable = false;

    const innerData = {
        date: Date.now(),
        subject: '',
        amount: 0,
        targetAccount: null
    }

    if (data) {
        innerData.date = data.date;
        innerData.subject = data.subject;
        innerData.amount = data.amount;
        innerData.targetAccount = data.targetAccount;
        removable = true;
    }

    let d = new Date(innerData.date);
    let formattedDate = (""+d.getDay()).padStart(2, "0") + "-" + (""+(d.getMonth() + 1)).padStart(2, "0") + "-" + d.getFullYear();

    gadgets.push({
        kind: 'string', id: 1, label: 'Subject:',
        left: sp + 80, top: y, width: 400 - sp - 80 - sp, height: rh,
        value: innerData.subject
    });
    gadgets.push({
        kind: 'string', id: 2, label: 'Amount:',
        left: sp + 80, top: sp + rh + sp, width: 100, height: rh,
        value: innerData.amount.toFixed(2)
    });
    gadgets.push({
        kind: 'string', id: 3, label: 'Date:',
        left: sp + 80, top: sp + rh + sp + rh + sp, width: 150, height: rh,
        value: formattedDate
    });
    gadgets.push({ kind: 'checkbox', id: 6, label: "Account:", left: sp + 80, top: sp + rh + sp + rh + sp + rh + sp + 2, width: rh, height: rh, value: 0 });

    const accounts = getAccounts(projectData);

    gadgets.push({ kind: 'cycle', id: 7, left: sp + 160 + rh + sp, top: sp + rh + sp + rh + sp + rh + sp, width: 120, height: rh, items: accounts, value: 0 });

    gadgets.push({ kind: 'button', id: 4, left: sp + 80, top: sp + rh + sp + rh + sp + rh + sp + rh + sp, width: 80, label: "Save", height: rh });
    gadgets.push({ kind: 'button', id: 5, left: sp + 80 + sp + 80, top: sp + rh + sp + rh + sp + rh + sp + rh + sp, width: 80, label: "Remove", height: rh });

    let win = gui.createWindow({
        title: 'Entry Details',
        width: 400,
        height: sp + rh + sp + rh + sp + rh + sp + rh + sp + rh + sp,
        left: 30,
        top: 30,
        gadgets: gadgets
    });

    if (innerData.targetAccount) {
        gui.set(win, 6, 1);
        let i = -1;
        for (i = 0; i < accounts.length; i++) {
            if (accounts[i] === innerData.targetAccount) {
                break;
            }
        }
        gui.set(win, 7, i);
        gui.setDisabled(win, 7, false);
    } else {
        gui.setDisabled(win, 7, true);
    }

    gui.setDisabled(win, 5, !removable);

    while (true) {
        var evt = gui.waitEvent(win);
        if (!evt) continue;

        if (evt.type === 'close') {
            gui.closeWindow(win);
            return null;
        }
        if (evt.type === 'gadgetup') {
            if (evt.id === 6) {
                gui.setDisabled(win, 7, !gui.get(win, 6));
            }
            if (evt.id === 4) {
                innerData.subject = gui.get(win, 1);
                innerData.amount = parseFloat(gui.get(win, 2));
                innerData.date = toDateByComponents(gui.get(win, 3));

                if (gui.get(win, 6)) {
                    const targetAccountIndex = gui.get(win, 7);
                    if (targetAccountIndex !== null && targetAccountIndex !== undefined) {
                        innerData.targetAccount = data[targetAccountIndex].name;
                    }
                }

                gui.closeWindow(win);
                return innerData;
            }
            if (evt.id === 5) {
                gui.closeWindow(win);
                return -1;
            }
        }
    }
}

function mainWindow(projectData) {

    let internalProjectData = projectData;

    let invalidate = false;

    let gadgets = [];

    const cycleId = 1;
    const listViewId = 2;
    const balanceId = 3;
    const addButtonId = 4;

    cols = 56;

    gadgets.push({
        kind: 'cycle', id: cycleId,
        left: sp, top: y, width: 120, height: rh, border: false,
        items: getAccounts(internalProjectData), value: 0
    });

    gadgets.push({ kind: 'button', id: addButtonId, left: 500 - 80 - sp, top: y, width: 80, label: "+Transfer", height: rh });

    gadgets.push({
        kind: 'listview', id: listViewId, left: sp, top: y + rh + sp, width: 500 - sp - sp, height: 186,
        flex: true,
        items: toListViewEntries(internalProjectData[0].entries, cols), value: 0
    });

    gadgets.push({
        kind: 'text', id: balanceId, label: 'Balance:',
        left: 100, top: y + rh + sp + 186, width: 400 - sp, height: rh,
        value: getSummation(internalProjectData[0].entries).toFixed(2)
    });



    let win = gui.createWindow({
        title: 'Budget',
        width: 500,
        height: 14 + 4 + 4 + 200 + 4,
        left: 20,
        top: 15,
        gadgets: gadgets
    });

    /* Set up menu bar */
    gui.setMenu(win, [
        {
            title: 'Project',
            items: [
                { label: 'New...', id: 101, key: 'N' },
                { label: 'Open...', id: 102, key: 'O' },
                { label: 'Save...', id: 103, key: 'S' },
                { label: '---' },
                { label: 'Quit', id: 199, key: 'Q' }
            ]
        },
    ]);

    let currentAccountIndex = 0;

    let updateView = (g, w, accountIndex, data) => {
        g.set(w, 2, toListViewEntries(data[accountIndex].entries, cols));
        g.set(w, 3, getSummation(data[accountIndex].entries).toFixed(2));
    }

    let doNew = () => {
        invalidate = true;
        return [
            {
                name: "Current",
                entries: []
            }
        ];
    }

    let doOpen = () => {
        var r = gui.fileRequest({ title: 'Open File', pattern: '#?.json' });
        if (r) {
            return JSON.parse(fs.readFileSync(r.file));
        }
        invalidate = false;
    }

    function doSave() {
        var r = gui.fileRequest({ title: 'Save File', pattern: '#?.json', save: true });
        if (r) {
            fs.writeFileSync(r.file, JSON.stringify(internalProjectData));
        }
    }



    while (!invalidate) {
        var evt = gui.waitEvent(win);
        if (!evt) continue;

        if (evt.type === 'close') {
            invalidate = true;
            internalProjectData = null;
        }

        if (evt.type === 'menu') {
            if (evt.id === 101) {
                internalProjectData = doNew();
                break;
            }
            else if (evt.id === 102) {
                internalProjectData = doOpen();
                break;
            }
            else if (evt.id === 103) doSave();
            else if (evt.id === 199) { 
                invalidate = true;
                internalProjectData = null;
            }
        }

        if (evt.type === 'gadgetup') {

            if (evt.id === cycleId) {
                currentAccountIndex = evt.code;
                updateView(gui, win, currentAccountIndex, internalProjectData);
            } else if (evt.id === listViewId) {
                const entry = subWindow(internalProjectData[currentAccountIndex].entries[evt.code]);
                if (entry != null) {
                    if (entry === -1) {
                        internalProjectData[currentAccountIndex].entries.splice(evt.code, 1);
                    } else {
                        internalProjectData[currentAccountIndex].entries[evt.code] = entry;
                    }
                    if (entry.targetAccount) {
                        const targetAccount = internalProjectData.find(d => d.name === entry.targetAccount);
                        if (targetAccount) {
                            targetAccount.entries.push({
                                date: entry.date,
                                subject: "(" + internalProjectData[currentAccountIndex].name + ")" + entry.subject,
                                amount: -entry.amount
                            });
                        }
                    }
                    updateView(gui, win, currentAccountIndex, internalProjectData);
                }
            } else if (evt.id === addButtonId) {
                const entry = subWindow();
                if (entry != null) {
                    internalProjectData[currentAccountIndex].entries.push(entry);

                    if (entry.targetAccount) {
                        const targetAccount = internalProjectData.find(d => d.name === entry.targetAccount);
                        if (targetAccount) {
                            targetAccount.entries.push({
                                date: entry.date,
                                subject: "(" + internalProjectData[currentAccountIndex].name + ")" + entry.subject,
                                amount: -entry.amount
                            });
                        }
                    }
                    updateView(gui, win, currentAccountIndex, internalProjectData);
                }
            }
        }
    };


    gui.closeWindow(win);
    return internalProjectData;
}


    let projectData = [
        {
            name: "Current",
            entries: [
                {
                    date: 1704067200000,
                    subject: '(Savings) Initial Deposit',
                    amount: -500,
                    targetAccount: "Savings"
                },
                {
                    date: 1704067200000,
                    subject: 'Salary',
                    amount: 2182.15
                },
                {
                    date: 1704153600000,
                    subject: 'Rent',
                    amount: -800
                },
                {
                    date: 1704240000000,
                    subject: 'Groceries',
                    amount: -24.19
                }
            ],
        },
        {
            name: "Savings",
            entries: [
                {
                    date: 1704067200000,
                    subject: 'Initial Deposit',
                    amount: 500
                }
            ],
        }

    ];


do {
    projectData = mainWindow(projectData);
} while(projectData != null);
console.log("bye!");