/*
fore.st is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

fore.st is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with fore.st. If not, see < http://www.gnu.org/licenses/ >.
(C) 2022- by rainbownapkin, <ourforest@420blaze.it>

Original cytube license:
MIT License

Copyright (c) 2013-2022 Calvin Montgomery

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

CyTube.tabCompleteMethods = {};

// Bash-style completion
// Only completes as far as it is possible to maintain uniqueness of the completion.
CyTube.tabCompleteMethods['Longest unique match'] = function (input, position, options, context) {
    var lower = input.toLowerCase();
    // First, backtrack to the nearest whitespace to find the
    // incomplete string that should be completed.
    var start;
    var incomplete = '';
    for (start = position - 1; start >= 0; start--) {
        if (/\s/.test(lower[start])) {
            break;
        }

        incomplete = lower[start] + incomplete;
    }
    start++;

    // Nothing to complete
    if (!incomplete.length) {
        return {
            text: input,
            newPosition: position
        };
    }

    var matches = options.filter(function (option) {
        return option.toLowerCase().indexOf(incomplete) === 0;
    });

    var completed;
    var isFullMatch = false;
    if (matches.length === 0) {
        return {
            text: input,
            newPosition: position
        };
    } else if (matches.length === 1) {
        // Unique match
        completed = matches[0];
        isFullMatch = true;
    } else {
        // There is not a unique match, find the longest possible prefix
        // that results in a unique completion
        // Do this by comparing each match to the next and trimming to the
        // first index where they differ.
        var currentPrefix = null;
        for (var i = 0; i < matches.length - 1; i++) {
            var first = matches[i];
            var second = matches[i+1];
            var nextPrefix = '';
            for (var j = 0; (currentPrefix === null || j < currentPrefix.length)
                    && j < first.length
                    && j < second.length; j++) {
                if (first[j].toLowerCase() === second[j].toLowerCase()) {
                    nextPrefix += first[j];
                } else {
                    break;
                }
            }

            if (currentPrefix === null || nextPrefix.length < currentPrefix.length) {
                currentPrefix = nextPrefix;
            }
        }

        completed = currentPrefix;
    }

    var space = isFullMatch ? ' ' : '';
    return {
        text: input.substring(0, start) + completed + space + input.substring(position),
        newPosition: start + completed.length + space.length
    };
};

// Zsh-style completion.
// Always complete a full option, and cycle through available options on successive tabs
CyTube.tabCompleteMethods['Cycle options'] = function (input, position, options, context) {
    if (typeof context.start !== 'undefined') {
        var currentCompletion = input.substring(context.start, position - 1);
        if (currentCompletion === context.matches[context.tabIndex]) {
            context.tabIndex = (context.tabIndex + 1) % context.matches.length;
            var completed = context.matches[context.tabIndex];
            return {
                text: input.substring(0, context.start) + completed + ' ' + input.substring(position),
                newPosition: context.start + completed.length + 1
            };
        } else {
            delete context.matches;
            delete context.tabIndex;
            delete context.start;
        }
    }

    var lower = input.toLowerCase();
    // First, backtrack to the nearest whitespace to find the
    // incomplete string that should be completed.
    var start;
    var incomplete = '';
    for (start = position - 1; start >= 0; start--) {
        if (/\s/.test(lower[start])) {
            break;
        }

        incomplete = lower[start] + incomplete;
    }
    start++;

    // Nothing to complete
    if (!incomplete.length) {
        return {
            text: input,
            newPosition: position
        };
    }

    var matches = options.filter(function (option) {
        return option.toLowerCase().indexOf(incomplete) === 0;
    }).sort(function (a, b) {
        var aLower = a.toLowerCase();
        var bLower = b.toLowerCase();

        if (aLower > bLower) {
            return 1;
        } else if (aLower < bLower) {
            return -1;
        } else {
            return 0;
        }
    });

    if (matches.length === 0) {
        return {
            text: input,
            newPosition: position
        };
    }

    context.start = start;
    context.matches = matches;
    context.tabIndex = 0;
    return {
        text: input.substring(0, start) + matches[0] + input.substring(position),
        newPosition: start + matches[0].length + 1
    };
};