/* jslint node: true */
'use strict';

//  ENiGMA½
const MenuView      = require('./menu_view.js').MenuView;
const ansi          = require('./ansi_term.js');
const strUtil       = require('./string_util.js');
const formatString  = require('./string_format');
const pipeToAnsi    = require('./color_codes.js').pipeToAnsi;

//  deps
const util          = require('util');
const _             = require('lodash');

exports.VerticalMenuView        = VerticalMenuView;

function VerticalMenuView(options) {
    options.cursor          = options.cursor || 'hide';
    options.justify         = options.justify || 'left';

    MenuView.call(this, options);

    this.initDefaultWidth();

    const self = this;

    //  we want page up/page down by default
    if(!_.isObject(options.specialKeyMap)) {
        Object.assign(this.specialKeyMap, {
            'page up'       : [ 'page up' ],
            'page down'     : [ 'page down' ],
        });
    }

    this.autoAdjustHeightIfEnabled = function() {
        if(this.autoAdjustHeight) {
            this.dimens.height = (this.items.length * (this.itemSpacing + 1)) - (this.itemSpacing);
            this.dimens.height = Math.min(this.dimens.height, this.client.term.termHeight - this.position.row);
        }
    };

    this.autoAdjustHeightIfEnabled();

    this.updateViewVisibleItems = function() {
        self.maxVisibleItems = Math.ceil(self.dimens.height / (self.itemSpacing + 1));

        self.viewWindow = {
            top     : self.focusedItemIndex,
            bottom  : Math.min(self.focusedItemIndex + self.maxVisibleItems, self.items.length) - 1,
        };
    };

    this.drawItem = function(index) {
        const item = self.items[index];
        if(!item) {
            return;
        }

        const cached = this.getRenderCacheItem(index, item.focused);
        if(cached) {
            return self.client.term.write(`${ansi.goto(item.row, self.position.col)}${cached}`);
        }

        let text;
        let sgr;
        if(item.focused && self.hasFocusItems()) {
            const focusItem = self.focusItems[index];
            text = focusItem ? focusItem.text : item.text;
            sgr = '';
        } else if(this.complexItems) {
            text = pipeToAnsi(formatString(item.focused && this.focusItemFormat ? this.focusItemFormat : this.itemFormat, item));
            sgr = this.focusItemFormat ? '' : (index === self.focusedItemIndex ? self.getFocusSGR() : self.getSGR());
        } else {
            text = strUtil.stylizeString(item.text, item.focused ? self.focusTextStyle : self.textStyle);
            sgr = (index === self.focusedItemIndex ? self.getFocusSGR() : self.getSGR());
        }

        text = `${sgr}${strUtil.pad(text, this.dimens.width, this.fillChar, this.justify)}`;
        self.client.term.write(`${ansi.goto(item.row, self.position.col)}${text}`);
        this.setRenderCacheItem(index, text, item.focused);
    };
}

util.inherits(VerticalMenuView, MenuView);

VerticalMenuView.prototype.redraw = function() {
    VerticalMenuView.super_.prototype.redraw.call(this);

    //  :TODO: rename positionCacheExpired to something that makese sense; combine methods for such
    if(this.positionCacheExpired) {
        this.autoAdjustHeightIfEnabled();
        this.updateViewVisibleItems();

        this.positionCacheExpired = false;
    }

    //  erase old items
    //  :TODO: optimize this: only needed if a item is removed or new max width < old.
    if(this.oldDimens) {
        const blank     = new Array(Math.max(this.oldDimens.width, this.dimens.width)).join(' ');
        let seq         = ansi.goto(this.position.row, this.position.col) + this.getSGR() + blank;
        let row         = this.position.row + 1;
        const endRow    = (row + this.oldDimens.height) - 2;

        while(row <= endRow) {
            seq += ansi.goto(row, this.position.col) + blank;
            row += 1;
        }
        this.client.term.write(seq);
        delete this.oldDimens;
    }

    if(this.items.length) {
        let row = this.position.row;
        for(let i = this.viewWindow.top; i <= this.viewWindow.bottom; ++i) {
            this.items[i].row = row;
            row += this.itemSpacing + 1;
            this.items[i].focused = this.focusedItemIndex === i;
            this.drawItem(i);
        }
    }
};

VerticalMenuView.prototype.setHeight = function(height) {
    VerticalMenuView.super_.prototype.setHeight.call(this, height);

    this.positionCacheExpired = true;
    this.autoAdjustHeight = false;
};

VerticalMenuView.prototype.setPosition = function(pos) {
    VerticalMenuView.super_.prototype.setPosition.call(this, pos);

    this.positionCacheExpired = true;
};

VerticalMenuView.prototype.setFocus = function(focused) {
    VerticalMenuView.super_.prototype.setFocus.call(this, focused);

    this.redraw();
};

VerticalMenuView.prototype.setFocusItemIndex = function(index) {
    VerticalMenuView.super_.prototype.setFocusItemIndex.call(this, index);  //  sets this.focusedItemIndex

    const remainAfterFocus = this.items.length - index;
    if(remainAfterFocus >= this.maxVisibleItems) {
        this.viewWindow = {
            top     : this.focusedItemIndex,
            bottom  : Math.min(this.focusedItemIndex + this.maxVisibleItems, this.items.length) - 1
        };

        this.positionCacheExpired = false;  //  skip standard behavior
        this.autoAdjustHeightIfEnabled();
    }

    this.redraw();
};

VerticalMenuView.prototype.onKeyPress = function(ch, key) {
    if(key) {
        if(this.isKeyMapped('up', key.name)) {
            this.focusPrevious();
        } else if(this.isKeyMapped('down', key.name)) {
            this.focusNext();
        } else if(this.isKeyMapped('page up', key.name)) {
            this.focusPreviousPageItem();
        } else if(this.isKeyMapped('page down', key.name)) {
            this.focusNextPageItem();
        } else if(this.isKeyMapped('home', key.name)) {
            this.focusFirst();
        } else if(this.isKeyMapped('end', key.name)) {
            this.focusLast();
        }
    }

    VerticalMenuView.super_.prototype.onKeyPress.call(this, ch, key);
};

VerticalMenuView.prototype.getData = function() {
    const item = this.getItem(this.focusedItemIndex);
    return _.isString(item.data) ? item.data : this.focusedItemIndex;
};

VerticalMenuView.prototype.setItems = function(items) {
    //  if we have items already, save off their drawing area so we don't leave fragments at redraw
    if(this.items && this.items.length) {
        this.oldDimens = Object.assign({}, this.dimens);
    }

    VerticalMenuView.super_.prototype.setItems.call(this, items);

    this.positionCacheExpired = true;
};

VerticalMenuView.prototype.removeItem = function(index) {
    if(this.items && this.items.length) {
        this.oldDimens = Object.assign({}, this.dimens);
    }

    VerticalMenuView.super_.prototype.removeItem.call(this, index);
};

//  :TODO: Apply draw optimizaitons when only two items need drawn vs entire view!

VerticalMenuView.prototype.focusNext = function() {
    if(this.items.length - 1 === this.focusedItemIndex) {
        this.focusedItemIndex = 0;

        this.viewWindow = {
            top     : 0,
            bottom  : Math.min(this.maxVisibleItems, this.items.length) - 1
        };
    } else {
        this.focusedItemIndex++;

        if(this.focusedItemIndex > this.viewWindow.bottom) {
            this.viewWindow.top++;
            this.viewWindow.bottom++;
        }
    }

    this.redraw();

    VerticalMenuView.super_.prototype.focusNext.call(this);
};

VerticalMenuView.prototype.focusPrevious = function() {
    if(0 === this.focusedItemIndex) {
        this.focusedItemIndex = this.items.length - 1;

        this.viewWindow = {
            //top       : this.items.length - this.maxVisibleItems,
            top     : Math.max(this.items.length - this.maxVisibleItems, 0),
            bottom  : this.items.length - 1
        };

    } else {
        this.focusedItemIndex--;

        if(this.focusedItemIndex < this.viewWindow.top) {
            this.viewWindow.top--;
            this.viewWindow.bottom--;

            //  adjust for focus index being set & window needing expansion as we scroll up
            const rem = (this.viewWindow.bottom - this.viewWindow.top) + 1;
            if(rem < this.maxVisibleItems && (this.items.length - 1) > this.focusedItemIndex) {
                this.viewWindow.bottom = this.items.length - 1;
            }
        }
    }

    this.redraw();

    VerticalMenuView.super_.prototype.focusPrevious.call(this);
};

VerticalMenuView.prototype.focusPreviousPageItem = function() {
    //
    //  Jump to current - up to page size or top
    //  If already at the top, jump to bottom
    //
    if(0 === this.focusedItemIndex) {
        return this.focusPrevious();    //  will jump to bottom
    }

    const index = Math.max(this.focusedItemIndex - this.dimens.height, 0);

    if(index < this.viewWindow.top) {
        this.oldDimens = Object.assign({}, this.dimens);
    }

    this.setFocusItemIndex(index);

    return VerticalMenuView.super_.prototype.focusPreviousPageItem.call(this);
};

VerticalMenuView.prototype.focusNextPageItem = function() {
    //
    //  Jump to current + up to page size or bottom
    //  If already at the bottom, jump to top
    //
    if(this.items.length - 1 === this.focusedItemIndex) {
        return this.focusNext();    //  will jump to top
    }

    const index = Math.min(this.focusedItemIndex + this.maxVisibleItems, this.items.length - 1);

    if(index > this.viewWindow.bottom) {
        this.oldDimens = Object.assign({}, this.dimens);

        this.focusedItemIndex = index;

        this.viewWindow = {
            top     : this.focusedItemIndex,
            bottom  : Math.min(this.focusedItemIndex + this.maxVisibleItems, this.items.length) - 1
        };

        this.redraw();
    } else {
        this.setFocusItemIndex(index);
    }

    return VerticalMenuView.super_.prototype.focusNextPageItem.call(this);
};

VerticalMenuView.prototype.focusFirst = function() {
    if(0 < this.viewWindow.top) {
        this.oldDimens = Object.assign({}, this.dimens);
    }
    this.setFocusItemIndex(0);
    return VerticalMenuView.super_.prototype.focusFirst.call(this);
};

VerticalMenuView.prototype.focusLast = function() {
    const index = this.items.length - 1;

    if(index > this.viewWindow.bottom) {
        this.oldDimens = Object.assign({}, this.dimens);

        this.focusedItemIndex = index;

        this.viewWindow = {
            top     : this.focusedItemIndex,
            bottom  : Math.min(this.focusedItemIndex + this.maxVisibleItems, this.items.length) - 1
        };

        this.redraw();
    } else {
        this.setFocusItemIndex(index);
    }

    return VerticalMenuView.super_.prototype.focusLast.call(this);
};

VerticalMenuView.prototype.setFocusItems = function(items) {
    VerticalMenuView.super_.prototype.setFocusItems.call(this, items);

    this.positionCacheExpired = true;
};

VerticalMenuView.prototype.setItemSpacing = function(itemSpacing) {
    VerticalMenuView.super_.prototype.setItemSpacing.call(this, itemSpacing);

    this.positionCacheExpired = true;
};