| 11 | } |
| 12 | |
| 13 | function parse( |
| 14 | raw: string, |
| 15 | preferences: readonly string[] | undefined, |
| 16 | options: Options |
| 17 | ) { |
| 18 | const lowers = new Map<string, { orig: string; pos: number }>() |
| 19 | const header = raw.replace(/[ \t]/g, '') |
| 20 | |
| 21 | if (preferences) { |
| 22 | let pos = 0 |
| 23 | for (const preference of preferences) { |
| 24 | const lower = preference.toLowerCase() |
| 25 | lowers.set(lower, { orig: preference, pos: pos++ }) |
| 26 | if (options.prefixMatch) { |
| 27 | const parts = lower.split('-') |
| 28 | while ((parts.pop(), parts.length > 0)) { |
| 29 | const joined = parts.join('-') |
| 30 | if (!lowers.has(joined)) { |
| 31 | lowers.set(joined, { orig: preference, pos: pos++ }) |
| 32 | } |
| 33 | } |
| 34 | } |
| 35 | } |
| 36 | } |
| 37 | |
| 38 | const parts = header.split(',') |
| 39 | const selections: Selection[] = [] |
| 40 | const map = new Set<string>() |
| 41 | |
| 42 | for (let i = 0; i < parts.length; ++i) { |
| 43 | const part = parts[i] |
| 44 | if (!part) { |
| 45 | continue |
| 46 | } |
| 47 | |
| 48 | const params = part.split(';') |
| 49 | if (params.length > 2) { |
| 50 | throw new Error(`Invalid ${options.type} header`) |
| 51 | } |
| 52 | |
| 53 | let token = params[0].toLowerCase() |
| 54 | if (!token) { |
| 55 | throw new Error(`Invalid ${options.type} header`) |
| 56 | } |
| 57 | |
| 58 | const selection: Selection = { token, pos: i, q: 1 } |
| 59 | if (preferences && lowers.has(token)) { |
| 60 | selection.pref = lowers.get(token)!.pos |
| 61 | } |
| 62 | |
| 63 | map.add(selection.token) |
| 64 | |
| 65 | if (params.length === 2) { |
| 66 | const q = params[1] |
| 67 | const [key, value] = q.split('=') |
| 68 | |
| 69 | if (!value || (key !== 'q' && key !== 'Q')) { |
| 70 | throw new Error(`Invalid ${options.type} header`) |