// https://gomakethings.com/finding-the-next-and-previous-sibling-elements-that-match-a-selector-with-vanilla-js/
function getNextSibling(elem, selector) {
	// Get the next sibling element
	var sibling = elem.nextElementSibling

	// If there's no selector, return the first sibling
	if (!selector) return sibling

	// If the sibling matches our selector, use it
	// If not, jump to the next sibling and continue the loop
	while (sibling) {
		if (sibling.matches(selector)) return sibling
		sibling = sibling.nextElementSibling
	}
}

function createCollapsibles(node) {
    if (!node) {
        node = document
    }

    let collapsibles = node.querySelectorAll(".collapsible")
    collapsibles.forEach(function(c) {
        let handle = document.createElement('span')
        handle.className = 'collapsible-handle'

        if (c.className.indexOf('active') !== -1) {
            handle.innerHTML = '➖' // minus
        } else {
            handle.innerHTML = '➕' // plus
        }
        c.insertBefore(handle, c.firstChild)

        c.addEventListener('click', function() {
            this.classList.toggle("active")
            let content = getNextSibling(this, '.collapsible-content')
            if (content.style.display === "block") {
                content.style.display = "none"
                handle.innerHTML = '➕' // plus
            } else {
                content.style.display = "block"
                handle.innerHTML = '➖' // minus
            }

            if (this == advancedPanelHandle) {
                let state = (content.style.display === 'block' ? 'true' : 'false')
                localStorage.setItem(ADVANCED_PANEL_OPEN_KEY, state)
            } else if (this == modifiersPanelHandle) {
                let state = (content.style.display === 'block' ? 'true' : 'false')
                localStorage.setItem(MODIFIERS_PANEL_OPEN_KEY, state)
            } else if (this == negativePromptPanelHandle) {
                let state = (content.style.display === 'block' ? 'true' : 'false')
                localStorage.setItem(NEGATIVE_PROMPT_PANEL_OPEN_KEY, state)
            }
        })
    })
}

function permute(arr) {
    let permutations = []
    let n = arr.length
    let n_permutations = Math.pow(2, n)
    for (let i = 0; i < n_permutations; i++) {
        let perm = []
        let mask = Number(i).toString(2).padStart(n, '0')

        for (let idx = 0; idx < mask.length; idx++) {
            if (mask[idx] === '1' && arr[idx].trim() !== '') {
                perm.push(arr[idx])
            }
        }

        if (perm.length > 0) {
            permutations.push(perm)
        }
    }

    return permutations
}

// https://stackoverflow.com/a/8212878
function millisecondsToStr(milliseconds) {
    function numberEnding (number) {
        return (number > 1) ? 's' : ''
    }

    var temp = Math.floor(milliseconds / 1000)
    var hours = Math.floor((temp %= 86400) / 3600)
    var s = ''
    if (hours) {
        s += hours + ' hour' + numberEnding(hours) + ' '
    }
    var minutes = Math.floor((temp %= 3600) / 60)
    if (minutes) {
        s += minutes + ' minute' + numberEnding(minutes) + ' '
    }
    var seconds = temp % 60
    if (!hours && minutes < 4 && seconds) {
        s += seconds + ' second' + numberEnding(seconds)
    }

    return s
}

// https://rosettacode.org/wiki/Brace_expansion#JavaScript
function BraceExpander() {
    'use strict'

    // Index of any closing brace matching the opening
    // brace at iPosn,
    // with the indices of any immediately-enclosed commas.
    function bracePair(tkns, iPosn, iNest, lstCommas) {
        if (iPosn >= tkns.length || iPosn < 0) return null;

        var t = tkns[iPosn],
            n = (t === '{') ? (
                iNest + 1
            ) : (t === '}' ? (
                iNest - 1
            ) : iNest),
            lst = (t === ',' && iNest === 1) ? (
                lstCommas.concat(iPosn)
            ) : lstCommas;

        return n ? bracePair(tkns, iPosn + 1, n, lst) : {
            close: iPosn,
            commas: lst
        };
    }

    // Parse of a SYNTAGM subtree
    function andTree(dctSofar, tkns) {
        if (!tkns.length) return [dctSofar, []];

        var dctParse = dctSofar ? dctSofar : {
                fn: and,
                args: []
            },

            head = tkns[0],
            tail = head ? tkns.slice(1) : [],

            dctBrace = head === '{' ? bracePair(
                tkns, 0, 0, []
            ) : null,

            lstOR = dctBrace && (
                dctBrace.close
            ) && dctBrace.commas.length ? (
                splitAt(dctBrace.close + 1, tkns)
            ) : null;

        return andTree({
            fn: and,
            args: dctParse.args.concat(
                lstOR ? (
                    orTree(dctParse, lstOR[0], dctBrace.commas)
                ) : head
            )
        }, lstOR ? (
            lstOR[1]
        ) : tail);
    }

    // Parse of a PARADIGM subtree
    function orTree(dctSofar, tkns, lstCommas) {
        if (!tkns.length) return [dctSofar, []];
        var iLast = lstCommas.length;

        return {
            fn: or,
            args: splitsAt(
                lstCommas, tkns
            ).map(function (x, i) {
                var ts = x.slice(
                    1, i === iLast ? (
                        -1
                    ) : void 0
                );

                return ts.length ? ts : [''];
            }).map(function (ts) {
                return ts.length > 1 ? (
                    andTree(null, ts)[0]
                ) : ts[0];
            })
        };
    }

    // List of unescaped braces and commas, and remaining strings
    function tokens(str) {
        // Filter function excludes empty splitting artefacts
        var toS = function (x) {
            return x.toString();
        };

        return str.split(/(\\\\)/).filter(toS).reduce(function (a, s) {
            return a.concat(s.charAt(0) === '\\' ? s : s.split(
                /(\\*[{,}])/
            ).filter(toS));
        }, []);
    }

    // PARSE TREE OPERATOR (1 of 2)
    // Each possible head * each possible tail
    function and(args) {
        var lng = args.length,
            head = lng ? args[0] : null,
            lstHead = "string" === typeof head ? (
                [head]
            ) : head;

        return lng ? (
            1 < lng ? lstHead.reduce(function (a, h) {
                return a.concat(
                    and(args.slice(1)).map(function (t) {
                        return h + t;
                    })
                );
            }, []) : lstHead
        ) : [];
    }

    // PARSE TREE OPERATOR (2 of 2)
    // Each option flattened
    function or(args) {
        return args.reduce(function (a, b) {
            return a.concat(b);
        }, []);
    }

    // One list split into two (first sublist length n)
    function splitAt(n, lst) {
        return n < lst.length + 1 ? [
            lst.slice(0, n), lst.slice(n)
        ] : [lst, []];
    }

    // One list split into several (sublist lengths [n])
    function splitsAt(lstN, lst) {
        return lstN.reduceRight(function (a, x) {
            return splitAt(x, a[0]).concat(a.slice(1));
        }, [lst]);
    }

    // Value of the parse tree
    function evaluated(e) {
        return typeof e === 'string' ? e :
            e.fn(e.args.map(evaluated));
    }

    // JSON prettyprint (for parse tree, token list etc)
    function pp(e) {
        return JSON.stringify(e, function (k, v) {
            return typeof v === 'function' ? (
                '[function ' + v.name + ']'
            ) : v;
        }, 2)
    }


    // ----------------------- MAIN ------------------------

    // s -> [s]
    this.expand = function(s) {
        // BRACE EXPRESSION PARSED
        var dctParse = andTree(null, tokens(s))[0];

        // ABSTRACT SYNTAX TREE LOGGED
        // console.log(pp(dctParse));

        // AST EVALUATED TO LIST OF STRINGS
        return evaluated(dctParse);
    }

}