Extensive work on building, wearables, assets, inventory, attachments, serialization, etc.

Resolves #36

lib/classes/LLLindenText.ts

@@ -0,0 +1,182 @@
+import { InventoryItem } from './InventoryItem';
+
+export class LLLindenText
+{
+    version: number = 2;
+
+    private lineObj: {
+        lines: string[],
+        lineNum: number
+    } = {
+        lines: [],
+        lineNum: 0
+    };
+
+    body = '';
+    embeddedItems: {[key: number]: InventoryItem} = {};
+
+    constructor(data?: Buffer)
+    {
+        if (data !== undefined)
+        {
+            const initial = data.toString('ascii');
+            this.lineObj.lines = initial.replace(/\r\n/g, '\n').split('\n');
+
+            let line = this.getLine();
+            if (!line.startsWith('Linden text version'))
+            {
+                throw new Error('Invalid Linden Text header');
+            }
+            this.version = parseInt(this.getLastToken(line), 10);
+            if (this.version < 1 || this.version > 2)
+            {
+                throw new Error('Unsupported Linden Text version');
+            }
+            if (this.version === 2)
+            {
+                const v2 = data.toString('utf-8');
+                this.lineObj.lines = v2.replace(/\r\n/g, '\n').split('\n');
+            }
+            line = this.getLine();
+            if (line !== '{')
+            {
+                throw new Error('Error parsing Linden Text file');
+            }
+            line = this.getLine();
+            if (line.startsWith('LLEmbeddedItems'))
+            {
+                this.parseEmbeddedItems();
+                line = this.getLine();
+            }
+            if (!line.startsWith('Text length'))
+            {
+                throw new Error('Error parsing Linden Text file: ' + line);
+            }
+            let textLength = parseInt(this.getLastToken(line), 10);
+            do
+            {
+                line = this.getLine();
+                textLength -= Buffer.byteLength(line);
+                if (textLength < 0)
+                {
+                    const extraChars = 0 - textLength;
+                    const rest = line.substr(line.length - extraChars);
+                    line = line.substr(0, line.length - extraChars);
+                    this.lineObj.lines.splice(this.lineObj.lineNum, 0, rest);
+                    textLength = 0;
+                    this.body += line;
+                }
+                else
+                {
+                    this.body += line;
+                    if (textLength > 0)
+                    {
+                        this.body += '\n';
+                        textLength--;
+                    }
+                }
+            }
+            while (textLength > 0);
+            line = this.getLine();
+            if (line !== '}')
+            {
+                throw new Error('Error parsing Linden Text file');
+            }
+        }
+    }
+
+    toAsset(): Buffer
+    {
+        const lines: string[] = [];
+        lines.push('Linden text version ' + this.version);
+        lines.push('{');
+        const count = Object.keys(this.embeddedItems).length;
+        if (count > 0)
+        {
+            lines.push('LLEmbeddedItems version 1');
+            lines.push('{');
+            lines.push('count ' + String(count));
+            for (const key of Object.keys(this.embeddedItems))
+            {
+                lines.push('{');
+                lines.push('ext char index ' + key);
+                lines.push('\tinv_item\t0');
+                lines.push(this.embeddedItems[parseInt(key, 10)].toAsset('\t'));
+                lines.push('}');
+            }
+            lines.push('}');
+        }
+        lines.push('Text length ' + String(Buffer.byteLength(this.body)));
+        lines.push(this.body + '}\n\0');
+        if (this.version === 1)
+        {
+            return Buffer.from(lines.join('\n'), 'ascii');
+        }
+        return Buffer.from(lines.join('\n'), 'utf-8');
+    }
+
+    private parseEmbeddedItems()
+    {
+        let line = this.getLine();
+        if (line !== '{')
+        {
+            throw new Error('Invalid LLEmbeddedItems format (no opening brace)');
+        }
+        line = this.getLine();
+        if (!line.startsWith('count'))
+        {
+            throw new Error('Invalid LLEmbeddedItems format (no count)');
+        }
+        const itemCount = parseInt(this.getLastToken(line), 10);
+        for (let x = 0; x < itemCount; x++)
+        {
+            line = this.getLine();
+            if (line !== '{')
+            {
+                throw new Error('Invalid LLEmbeddedItems format (no item opening brace)');
+            }
+            line = this.getLine();
+            if (!line.startsWith('ext char index'))
+            {
+                throw new Error('Invalid LLEmbeddedItems format (no ext char index)');
+            }
+            const index = parseInt(this.getLastToken(line), 10);
+            line = this.getLine();
+            if (!line.startsWith('inv_item'))
+            {
+                throw new Error('Invalid LLEmbeddedItems format (no inv_item)');
+            }
+            const item = InventoryItem.fromAsset(this.lineObj);
+            this.embeddedItems[index] = item;
+            line = this.getLine();
+            if (line !== '}')
+            {
+                throw new Error('Invalid LLEmbeddedItems format (no closing brace)');
+            }
+        }
+        line = this.getLine();
+        if (line !== '}')
+        {
+            throw new Error('Error parsing Linden Text file');
+        }
+    }
+
+    private getLastToken(input: string): string
+    {
+        const index = input.lastIndexOf(' ');
+        if (index === -1)
+        {
+            return input;
+        }
+        else
+        {
+            return input.substr(index + 1);
+        }
+    }
+
+    private getLine(): string
+    {
+        return this.lineObj.lines[this.lineObj.lineNum++].trim().replace(/[\t ]+/g, ' ');
+    }
+
+}