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.getDate().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 closeAccount(data, selectedAccount) {
    let gadgets = [];

    const accountNameId = 301;
    const remainingId = 302;
    const transferCheckboxId = 303;
    const targetAccountId = 304;
    const executeButtonId = 305;

    gadgets.push({ kind: 'text', id: accountNameId, label: "Account:", left: sp+128, top: y, width: 200, height: rh, value: selectedAccount.name});
    const openStanding = getSummation(selectedAccount.entries);
    gadgets.push({ kind: 'text', id: remainingId, label: "Remaining " + (openStanding>0? "funds": "debt"), left: sp+128, top: y+rh+sp, width: 100, height: rh})
    gadgets.push({ kind: 'checkbox', id: transferCheckboxId, label: "Transfer to:", left: sp, top: y+rh+sp+rh+sp, height: rh, value: 0});
    let accounts = [];
    for (let i = 0; i < data.length; ++i) {
        if (data[i].name != selectedAccount.name) {
            accounts.push(data[i].name);
        }
    }
    gadgets.push({ kind: 'cycle', id: targetAccountId, left: sp+128, top: y+rh+sp+rh+sp, width: 120, height: rh, items: accounts, value: 0 });
    gadgets.push({ kind: 'button', id: executeButtonId, left: sp+128, top: y+rh+sp+rh+sp+rh+sp, height: rh, width: 120, label: "Close Account"})

    let win = gui.createWindow({
        title: "Close Account '" + selectedAccount.name + "'",
        width: sp+128+240+sp,
        height: y+rh+sp+rh+sp+rh+sp+rh+sp,
        left: 30,
        top: 30,
        gadgets: gadgets
    });

    gui.setDisabled(win, targetAccountId, true);
    gui.set(win, remainingId, openStanding.toFixed(2));

     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 === transferCheckboxId) {
                 gui.setDisabled(win, targetAccountId, !gui.get(win, transferCheckboxId));
            }
            if (evt.id === executeButtonId) {
                if (gui.get(win, transferCheckboxId)) {
                    let otherAccount;
                    let target = accounts[gui.get(win, targetAccountId)];
                    for (let i = 0; data.length;++i) {
                        if (data[i].name === target) {
                            otherAccount = data[i];
                            break;
                        }
                    }
                    if (otherAccount) {
                        otherAccount.entries.push({
                            date: Date.now(),
                            subject: '('+ selectedAccount.name + ') Closing Statement',
                            amount: -openStanding,
                            targetAccount: null
                        })
                    }
                    gui.closeWindow(win);
                    return -1;
                }
            }
        }
    }
}

function addAccount(data) {
    let gadgets = [];
    
    gadgets.push({ kind: 'string', id: 201, label: "Name:", left: sp + 80, top: y, width: 300, height: rh});
    gadgets.push({ kind: 'button', id: 202, label: "Open Account", left: sp+80, top: y + rh + sp, width: 100, height: rh});

    let win = gui.createWindow({
        title: "New Account",
        width: sp+80+300+sp,
        height: y + rh+ sp+ rh + sp,
        left: 30,
        top: 30,
        gadgets: gadgets
    });

    let indexOfNewAccount = -1;
    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 === 202) {
                const newAccountName = gui.get(win, 201);

                if (newAccountName.trim() != '') {
                    data.push(
                        {
                            name: newAccountName,
                            entries: []
                        }
                    )
                    indexOfNewAccount = data.findIndex( p => p.name == newAccountName);
                    console.log(indexOfNewAccount);
                    gui.closeWindow(win);
                    break;
                }
            }
        }
    }
    return indexOfNewAccount;
}

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

    const subjectInputId = 401;
    const amountInputId = 402;
    const dateInputId = 403;
    const transferCheckboxId = 404;
    const transferAccountInputId = 405;
    const executeButtonId = 406;
    const deleteButtonId = 407;

    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.getDate()).padStart(2, "0") + "-" + (""+(d.getMonth() + 1)).padStart(2, "0") + "-" + d.getFullYear();

    gadgets.push({
        kind: 'string', id: subjectInputId, label: 'Subject:',
        left: sp + 80, top: y, width: 400 - sp - 80 - sp, height: rh,
        value: innerData.subject
    });
    gadgets.push({
        kind: 'string', id: amountInputId, label: 'Amount:',
        left: sp + 80, top: sp + rh + sp, width: 100, height: rh,
        value: innerData.amount.toFixed(2)
    });
    gadgets.push({
        kind: 'string', id: dateInputId, label: 'Date:',
        left: sp + 80, top: sp + rh + sp + rh + sp, width: 150, height: rh,
        value: formattedDate
    });
    gadgets.push({ kind: 'checkbox', id: transferCheckboxId, 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: transferAccountInputId, 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: executeButtonId, left: sp + 80, top: sp + rh + sp + rh + sp + rh + sp + rh + sp, width: 80, label: "Save", height: rh });
    gadgets.push({ kind: 'button', id: deleteButtonId, 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, transferCheckboxId, 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, transferAccountInputId, false);
    } else {
        gui.setDisabled(win, transferAccountInputId, true);
    }

    gui.setDisabled(win, deleteButtonId, !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 === transferCheckboxId) {
                gui.setDisabled(win, transferAccountInputId, !gui.get(win, transferAccountInputId));
            }
            if (evt.id === executeButtonId) {
                innerData.subject = gui.get(win, subjectInputId);
                innerData.amount = parseFloat(gui.get(win, amountInputId));
                innerData.date = toDateByComponents(gui.get(win, dateInputId));

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

                gui.closeWindow(win);
                return innerData;
            }
            if (evt.id === deleteButtonId) {
                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' }
            ]
        },
        {
            title: 'Accounts',
            items: [
                { label: "Add...", id:104, key: 'A'},
                { label: "Close...", id:105, key: 'C'}
            ]
        }
    ]);

    let currentAccountIndex = 0;

    let updateView = (accountIndex, data) => {
        if (accountIndex!=null) {
            gui.set(win, cycleId, getAccounts(data));
            gui.set(win, cycleId, accountIndex);
        }else {
            accountIndex = gui.get(win, cycleId);
        }
        gui.set(win, 2, toListViewEntries(data[accountIndex].entries, cols));
        gui.set(win, 3, getSummation(data[accountIndex].entries).toFixed(2));    
    }

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

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

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

    gui.setMenuItem(win, 105, {disabled: internalProjectData.length<=1});


    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();
                updateView(0, internalProjectData);
            }
            else if (evt.id === 102) {
                internalProjectData = doOpen();
                updateView(0, internalProjectData);
            }
            else if (evt.id === 103) {
                doSave();
            }
            else if (evt.id === 104) {
                let indexOfNewAccount = addAccount(internalProjectData);
                if (indexOfNewAccount > -1) {
                    currentAccountIndex = indexOfNewAccount;
                }
                updateView(currentAccountIndex, internalProjectData);
            }
            else if (evt.id === 105) {
                if (internalProjectData.length > 1) {
                    const rValue = closeAccount(internalProjectData, internalProjectData[currentAccountIndex]);
                    if (rValue === -1) {
                        internalProjectData.splice(currentAccountIndex, 1);
                        updateView(0, internalProjectData);
                    }
                } else {
                    gui.alert("Cannot close last remaining Account");
                }
                
            }
            else if (evt.id === 199) { 
                invalidate = true;
                internalProjectData = null;
            }
        }

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

            if (evt.id === cycleId) {
                currentAccountIndex = evt.code;
                updateView(null, 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(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(currentAccountIndex, internalProjectData);
                }
            }
        }
    };


    gui.closeWindow(win);
}


    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
                }
            ],
        }

    ];


mainWindow(projectData);