// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: https://codemirror.net/LICENSE

;(function (mod) {
    if (typeof exports == 'object' && typeof module == 'object')
        // CommonJS
        mod(require('../../lib/codemirror'))
    else if (typeof define == 'function' && define.amd)
        // AMD
        define(['../../lib/codemirror'], mod)
    // Plain browser env
    else mod(CodeMirror)
})(function (CodeMirror) {
    CodeMirror.defineExtension('addPanel', function (node, options) {
        options = options || {}

        if (!this.state.panels) initPanels(this)

        var info = this.state.panels
        var wrapper = info.wrapper
        var cmWrapper = this.getWrapperElement()
        var replace = options.replace instanceof Panel && !options.replace.cleared

        if (options.after instanceof Panel && !options.after.cleared) {
            wrapper.insertBefore(node, options.before.node.nextSibling)
        } else if (options.before instanceof Panel && !options.before.cleared) {
            wrapper.insertBefore(node, options.before.node)
        } else if (replace) {
            wrapper.insertBefore(node, options.replace.node)
            options.replace.clear(true)
        } else if (options.position == 'bottom') {
            wrapper.appendChild(node)
        } else if (options.position == 'before-bottom') {
            wrapper.insertBefore(node, cmWrapper.nextSibling)
        } else if (options.position == 'after-top') {
            wrapper.insertBefore(node, cmWrapper)
        } else {
            wrapper.insertBefore(node, wrapper.firstChild)
        }

        var height = (options && options.height) || node.offsetHeight

        var panel = new Panel(this, node, options, height)
        info.panels.push(panel)

        this.setSize()
        if (options.stable && isAtTop(this, node)) this.scrollTo(null, this.getScrollInfo().top + height)

        return panel
    })

    function Panel(cm, node, options, height) {
        this.cm = cm
        this.node = node
        this.options = options
        this.height = height
        this.cleared = false
    }

    /* when skipRemove is true, clear() was called from addPanel().
     * Thus removePanels() should not be called (issue 5518) */
    Panel.prototype.clear = function (skipRemove) {
        if (this.cleared) return
        this.cleared = true
        var info = this.cm.state.panels
        info.panels.splice(info.panels.indexOf(this), 1)
        this.cm.setSize()
        if (this.options.stable && isAtTop(this.cm, this.node)) this.cm.scrollTo(null, this.cm.getScrollInfo().top - this.height)
        info.wrapper.removeChild(this.node)
        if (info.panels.length == 0 && !skipRemove) removePanels(this.cm)
    }

    Panel.prototype.changed = function () {
        this.height = this.node.getBoundingClientRect().height
        this.cm.setSize()
    }

    function initPanels(cm) {
        var wrap = cm.getWrapperElement()
        var style = window.getComputedStyle ? window.getComputedStyle(wrap) : wrap.currentStyle
        var height = parseInt(style.height)
        var info = (cm.state.panels = {
            setHeight: wrap.style.height,
            panels: [],
            wrapper: document.createElement('div'),
        })
        var hasFocus = cm.hasFocus(),
            scrollPos = cm.getScrollInfo()
        wrap.parentNode.insertBefore(info.wrapper, wrap)
        info.wrapper.appendChild(wrap)
        cm.scrollTo(scrollPos.left, scrollPos.top)
        if (hasFocus) cm.focus()

        cm._setSize = cm.setSize
        if (height != null)
            cm.setSize = function (width, newHeight) {
                if (!newHeight) newHeight = info.wrapper.offsetHeight
                info.setHeight = newHeight
                if (typeof newHeight != 'number') {
                    var px = /^(\d+\.?\d*)px$/.exec(newHeight)
                    if (px) {
                        newHeight = Number(px[1])
                    } else {
                        info.wrapper.style.height = newHeight
                        newHeight = info.wrapper.offsetHeight
                    }
                }
                var editorheight =
                    newHeight -
                    info.panels
                        .map(function (p) {
                            return p.node.getBoundingClientRect().height
                        })
                        .reduce(function (a, b) {
                            return a + b
                        }, 0)
                cm._setSize(width, editorheight)
                height = newHeight
            }
    }

    function removePanels(cm) {
        var info = cm.state.panels
        cm.state.panels = null

        var wrap = cm.getWrapperElement()
        var hasFocus = cm.hasFocus(),
            scrollPos = cm.getScrollInfo()
        info.wrapper.parentNode.replaceChild(wrap, info.wrapper)
        cm.scrollTo(scrollPos.left, scrollPos.top)
        if (hasFocus) cm.focus()
        wrap.style.height = info.setHeight
        cm.setSize = cm._setSize
        cm.setSize()
    }

    function isAtTop(cm, dom) {
        for (var sibling = dom.nextSibling; sibling; sibling = sibling.nextSibling) if (sibling == cm.getWrapperElement()) return true
        return false
    }
})