export interface ParseJSONResult<T> {
    parsedObjects: Array<T>
    remainingBuffer: Buffer<ArrayBuffer>
}

export function tryParseJSON<T>(buffer: Buffer<ArrayBuffer>): ParseJSONResult<T> {
    const parsedObjects: Array<T> = []
    let braceCount = 0
    let inString = false
    let escaped = false

    let objectStart = -1

    for (let i = 0; i < buffer.length; i++) {
        const ch = buffer[i]

        if (inString) {
            if (escaped) {
                escaped = false
                // backslash '\'
            } else if (ch === 0x5c) {
                escaped = true
                // double quote '"'
            } else if (ch === 0x22) {
                inString = false
            }
            // double quote '"'
        } else if (ch === 0x22) {
            inString = true
            // opening brace '{'
        } else if (ch === 0x7b) {
            if (braceCount === 0) {
                objectStart = i
            }
            braceCount++
            // closing brace '}'
        } else if (ch === 0x7d) {
            braceCount--
            if (braceCount === 0 && objectStart !== -1) {
                // full object from objectStart..i
                parsedObjects.push(JSON.parse(buffer.subarray(objectStart, i + 1).toString('utf-8')) as T)
                objectStart = -1
            }
        }
    }

    // any leftover (partial) object
    const remainingBuffer = objectStart >= 0 ? buffer.subarray(objectStart) : Buffer.alloc(0)
    return { parsedObjects, remainingBuffer }
}