### Dictionary Thread Navigation Enhancement - JavaScript

Source: https://context7.com/masteralice3104/nico_downloader/llms.txt

Enhances Niconico Dictionary (dic.nicovideo.jp) pages with features for loading more comments and bookmarking. It fetches and appends new comment threads, allows setting/removing bookmarks for specific comments, and provides navigation to bookmarked comments. This script is auto-initialized on dictionary pages.

```javascript
// Auto-initialized on dictionary pages
window.onload = function() {
    Start_Dic();
};

// Load next 30 comments
function next_30load() {
    document.getElementById("next_30").setAttribute("disabled", true);

    let kijiURL = kiji_URL_get(); // Get article URL
    let DL_URL = kijiURL + "/" + Number(end_res + 1) + "-";

    fetch(DL_URL, { method: "GET" })
        .then(response => response.text())
        .then(data => {
            const parser = new DOMParser();
            const doc = parser.parseFromString(data, "text/html");

            let res_head = doc.getElementsByClassName("st-bbs_reshead");
            let res_body = doc.getElementsByClassName("st-bbs_resbody");

            // Append elements to page
            for (let i = 0; i < res_body.length; i++) {
                let add_element = createElementFromHTML(res_head[i].outerHTML);
                document.getElementsByClassName("st-bbs_resbody")[document.getElementsByClassName("st-bbs_resbody").length - 1].after(add_element);

                add_element = createElementFromHTML(res_body[i].outerHTML);
                document.getElementsByClassName("st-bbs_reshead")[document.getElementsByClassName("st-bbs_reshead").length - 1].after(add_element);
            }

            refresh_resNo();
            resnumhead_plus();
        });
}

// Bookmark specific comment
function pin_dome(e) {
    let res_no = e.currentTarget.getAttribute("name");
    let kiji_URL = kiji_URL_get();

    if (e.currentTarget.innerText === "■") {
        // Remove bookmark
        Option_setWriting(kiji_URL, "0");
    } else {
        // Set bookmark
        Option_setWriting(kiji_URL, res_no);
    }
    resnumhead_plus();
}

// Jump to bookmarked comment
function threadpin_move() {
    let kiji_URL = kiji_URL_get();
    let id = Number(setOption(kiji_URL));

    if (id === 0) {
        location.href = kiji_URL + "/1-";
        return;
    }

    // Calculate page containing the comment
    let page = Math.floor(id / 30) * 30 + 1;
    let pageURL = kiji_URL + "/" + page;

    if (start_res > id || end_res < id) {
        location.href = pageURL + "#" + id.toString();
    } else {
        location.hash = id.toString();
    }
}

```

--------------------------------

### Manage User Settings with Chrome Storage and localStorage

Source: https://context7.com/masteralice3104/nico_downloader/llms.txt

This section details the handling of persistent user preferences using Chrome's storage API and localStorage. It includes functions for writing and reading various settings such as video download mode, HLS save behavior, debug logging, language preferences, and file format. It also covers initializing default settings and loading them on page load. Debug printing is conditional on the debug mode being enabled.

```javascript
// Write option to storage
Option_setWriting("video_downloading", "2"); // 0:smID, 1:title, 2:smID_title, 3:title_smID
Option_setWriting("video_hlssave", "1"); // 0:initial, 1:enabled
Option_setWriting("debug", "1"); // Enable debug logging
Option_setWriting("language_setting", "en"); // ja or en
Option_setWriting("downFile_setting", "mp4"); // mp4 or aac

// Read option from storage
const downloadMode = setOption("video_downloading");
const saveMode = setOption("video_hlssave");
const isDebug = setOption("debug");
const language = setOption("language_setting");
const fileFormat = setOption("downFile_setting");

// Debug printing (only outputs if debug mode enabled)
DebugPrint("Current download mode: " + downloadMode);

// Initialize default settings
defalt_dataWrite();

// Load options on page load
Options_onload();
```

--------------------------------

### Manage Download Button UI in Niconico Player

Source: https://context7.com/masteralice3104/nico_downloader/llms.txt

This snippet demonstrates how to create and update the download button interface within the Niconico video player. It covers initializing the downloader, updating button text with localization, creating a save button with event handlers, directly manipulating HTML content, and automatically opening system message dialogs. It relies on the NicoDownloaderClass.

```javascript
const downloader = new NicoDownloaderClass();

// Create initial button element
downloader.ButtonFirstMake();

// Update button text with localization
downloader.ButtonTextWrite("処理開始"); // "Processing start"
downloader.ButtonTextWrite("処理中"); // "Processing"
downloader.ButtonTextWrite("保存完了"); // "Save complete"

// Create save button with click handler
downloader.SaveButtonMake("sm12345_VideoTitle.mp4");

// Direct HTML update
const customHTML = '<button onclick="alert(\'test\')">Custom Button</button>';
downloader.ButtonInnerHTMLWrite(customHTML);

// Auto-open system message dialog
const autoOpenJS = downloader.SystemMessageAutoOpenToText();
// Returns properly escaped JavaScript for onclick attribute
```

--------------------------------

### Manage Video Download State and Progress

Source: https://context7.com/masteralice3104/nico_downloader/llms.txt

This snippet focuses on managing the state of video downloads to prevent concurrent operations and track loaded videos. It includes methods to check if a download is already in progress, set and reset the downloading state, verify if a video has already been processed, mark videos as loaded, track download progress percentage, and manage download failure counts. It utilizes the NicoDownloaderClass and logs output to the console.

```javascript
const downloader = new NicoDownloaderClass();

// Check if already downloading
if (downloader.VideoDownloadingCheck()) {
    console.log("Download in progress, exiting");
    return false;
}

// Start download process
downloader.VideoDownloadingSet(); // Sets downloading = true

// Check if video already loaded
const videoSM = "sm12345";
if (downloader.VideoLoadedCheck(videoSM)) {
    console.log("Video already processed");
} else {
    // Mark as loaded
    downloader.VideoLoadedSMIDSet(videoSM);

    // Perform download operations...

    // Reset when complete
    downloader.VideoDownloadingReset(); // Sets downloading = false
}

// Track download progress
downloader.DownloadPercentageSet(45); // Set to 45%
console.log("Progress:", downloader.DownloadPercentageGet() + "% ");

// Track download failures
downloader.DownloadFaultNumAdd(); // Increment failure count
if (downloader.DownloadFaultNumCheck() > 5) {
    console.error("Too many failures");
    downloader.DownloadFaultNumReset();
}
```

--------------------------------

### Automatic Video Download Workflow - JavaScript

Source: https://context7.com/masteralice3104/nico_downloader/llms.txt

Implements a periodic workflow to detect and download Niconico videos. It checks for valid URLs, prevents concurrent downloads, retrieves video metadata, generates filenames, and initiates the download process. Dependencies include Chrome Storage API and potentially other Niconico-related classes.

```javascript
// Main download function
async function VideoDown() {
    const NicoDownloader = new NicoDownloaderClass();
    const Nicovideo = new NicovideoClass();

    // Verify URL matches
    if (!Nicovideo.CheckNicovideoWatchURL()) return false;

    // Prevent concurrent downloads
    if (NicoDownloader.VideoDownloadingCheck()) return false;

    // Get video ID and metadata
    Nicovideo.video_sm = Nicovideo.VideoSmGet(NicoDownloader.MatchingSMIDArray);
    await Nicovideo.SetAllFromVideoSm(Nicovideo.video_sm);

    if (Nicovideo.video_sm === "" || Nicovideo.video_title === "") {
        throw new Error("video_sm or video_title is null");
    }

    // Generate filename
    let downFile_setting = await new Promise((resolve, reject) => {
        chrome.storage.local.get("downFile_setting", function(value) {
            if (chrome.runtime.lastError) {
                reject(chrome.runtime.lastError);
            } else {
                resolve(value.downFile_setting);
            }
        });
    });

    let video_name = NicoDownloader.VideoDownloadNameMake(
        Nicovideo.video_sm,
        Nicovideo.video_title,
        downFile_setting
    );
    Nicovideo.video_name = video_name;

    // Create UI button if not already loaded
    if (!NicoDownloader.VideoLoadedCheck(Nicovideo.video_sm)) {
        NicoDownloader.ButtonFirstMake();
        NicoDownloader.ButtonTextWrite("処理開始");
        NicoDownloader.SaveButtonMake(Nicovideo.video_name);

        if (!NicoDownloader.CheckBeforeDownload()) {
            throw new Error("CheckBeforeDownload ERROR");
        }

        // Extract master URL and download
        const masterURL = NicoDownloader.MasterURLGet();
        if (masterURL && masterURL.indexOf("delivery.domand.nicovideo.jp") !== -1) {
            await MovieDownload_domand(Nicovideo, NicoDownloader);
            NicoDownloader.VideoDownloadingReset();
            NicoDownloader.VideoLoadedSMIDSet(Nicovideo.video_sm);
        }
    }

    return true;
}

// Run every 2 seconds
let intervalId = setInterval(() => {
    try {
        VideoDown();
    } catch (e) {
        console.log(e);
    }
}, 2000);

```

--------------------------------

### NicoDownloaderClass: Orchestrate Video Download Workflow

Source: https://context7.com/masteralice3104/nico_downloader/llms.txt

The `NicoDownloaderClass` handles the core download logic, including button creation, video metadata fetching, HLS playlist processing, and segment extraction. It requires instances of `NicovideoClass` and `NicovideoM3u8` for full functionality. The output is a processed video file.

```javascript
const NicoDownloader = new NicoDownloaderClass();
const Nicovideo = new NicovideoClass();

// Check if URL matches Niconico watch page
if (Nicovideo.CheckNicovideoWatchURL()) {
    // Get video SM ID from URL
    Nicovideo.video_sm = Nicovideo.VideoSmGet(NicoDownloader.MatchingSMIDArray);

    // Fetch all video metadata
    await Nicovideo.SetAllFromVideoSm(Nicovideo.video_sm);

    // Create download filename
    let downFile_setting = "mp4"; // or "aac"
    let video_name = NicoDownloader.VideoDownloadNameMake(
        Nicovideo.video_sm,
        Nicovideo.video_title,
        downFile_setting
    );

    // Extract master M3U8 URL from system messages
    const masterURL = NicoDownloader.MasterURLGet();

    // Process M3U8 playlists
    await NicoDownloader.URLToM3u8Set("First", masterURL);
    NicoDownloader.M3u8ToAudioAndVideoUrlSet();
    await NicoDownloader.URLToM3u8Set("Audio", NicoDownloader.M3u8.AudioM3u8URL);
    await NicoDownloader.URLToM3u8Set("Video", NicoDownloader.M3u8.VideoM3u8URL);

    // Extract TS segment URLs
    NicoDownloader.TSURLs = NicoDownloader.M3u8Class.MakeURLListToTSURLs(NicoDownloader);
    NicoDownloader.TSFilenames = NicoDownloader.M3u8Class.MakeTSFileNameListtoArray(NicoDownloader);

    // Update UI
    NicoDownloader.ButtonTextWrite("処理中");
}
```

--------------------------------

### M3U8 Parsing and TS Segment URL Extraction

Source: https://context7.com/masteralice3104/nico_downloader/llms.txt

This snippet demonstrates how to parse M3U8 playlist content into a structured format and extract individual transport stream (TS) segment URLs. It involves using `NicoDownloaderClass` for parsing and `NicovideoM3u8` for generating TS filenames and URL lists. This is crucial for downloading fragmented video streams.

```javascript
const downloader = new NicoDownloaderClass();

// Parse M3U8 text to JSON structure
const m3u8Text = `#EXTM3U
#EXT-X-STREAM-INF:BANDWIDTH=1280000
https://example.com/video.m3u8
#EXT-X-MEDIA:URI="https://example.com/audio.m3u8"`;

const parsed = downloader.Parsem3u8(m3u8Text);
console.log(parsed);
// Returns: { "EXT-X-STREAM-INF": [...], "EXT-X-MEDIA": [...] }

// Download M3U8 with cookies
const m3u8Content = await downloader.DownloadTextWithCookie("https://delivery.domand.nicovideo.jp/hls/xxx/master.m3u8");

// Extract TS filenames from URLs
const m3u8Class = new NicovideoM3u8();
const filename = m3u8Class.MakeTSFilename("https://asset.domand.nicovideo.jp/video/segment001.ts?ht2_nicovideo=xxx");
console.log(filename); // "segment001.ts"

// Generate complete TS URL list
const tsUrls = m3u8Class.MakeURLListToTSURLs(downloader);
// Returns array: [audioMapURL, audioKeyURL, ...audioSegments, videoMapURL, videoKeyURL, ...videoSegments]
```

--------------------------------

### NicovideoClass: Fetch and Parse Niconico Video Metadata

Source: https://context7.com/masteralice3104/nico_downloader/llms.txt

The `NicovideoClass` is responsible for fetching detailed video metadata from Niconico's API endpoints. It allows retrieval of information such as title, view counts, comments, likes, and descriptions. This class can parse JSON data directly or be fed parsed JSON for processing.

```javascript
// Create instance and fetch video data
const nicovideo = new NicovideoClass();

// Fetch all metadata for a video
await nicovideo.SetAllFromVideoSm('sm9');

// Access video properties
console.log("Title:", nicovideo.video_title);
console.log("Views:", nicovideo.view_count);
console.log("Comments:", nicovideo.comment_count);
console.log("Mylists:", nicovideo.mylist_count);
console.log("Likes:", nicovideo.like_count);
console.log("Owner:", nicovideo.video_owner);
console.log("Registered:", nicovideo.video_registeredAt);
console.log("Description:", nicovideo.video_description);
console.log("Tags:", nicovideo.video_tags);
console.log("Genre:", nicovideo.video_genre);
console.log("Series:", nicovideo.video_series);

// Manual JSON download and parsing
const json = await nicovideo.DownloadJson('sm12345');
nicovideo.SetJson(json);
nicovideo.SetAll();
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.