import { CHAR_BACKWARD_SLASH } from "./_constants.ts";import { assertPath, isPosixPathSeparator } from "./_util.ts";import { posixResolve, windowsResolve } from "./_resolve.ts";
function assertArgs(from: string, to: string) { assertPath(from); assertPath(to); if (from === to) return "";}
export function posixRelative(from: string, to: string): string { assertArgs(from, to);
from = posixResolve(from); to = posixResolve(to);
if (from === to) return "";
let fromStart = 1; const fromEnd = from.length; for (; fromStart < fromEnd; ++fromStart) { if (!isPosixPathSeparator(from.charCodeAt(fromStart))) break; } const fromLen = fromEnd - fromStart;
let toStart = 1; const toEnd = to.length; for (; toStart < toEnd; ++toStart) { if (!isPosixPathSeparator(to.charCodeAt(toStart))) break; } const toLen = toEnd - toStart;
const length = fromLen < toLen ? fromLen : toLen; let lastCommonSep = -1; let i = 0; for (; i <= length; ++i) { if (i === length) { if (toLen > length) { if (isPosixPathSeparator(to.charCodeAt(toStart + i))) { return to.slice(toStart + i + 1); } else if (i === 0) { return to.slice(toStart + i); } } else if (fromLen > length) { if (isPosixPathSeparator(from.charCodeAt(fromStart + i))) { lastCommonSep = i; } else if (i === 0) { lastCommonSep = 0; } } break; } const fromCode = from.charCodeAt(fromStart + i); const toCode = to.charCodeAt(toStart + i); if (fromCode !== toCode) break; else if (isPosixPathSeparator(fromCode)) lastCommonSep = i; }
let out = ""; for (i = fromStart + lastCommonSep + 1; i <= fromEnd; ++i) { if (i === fromEnd || isPosixPathSeparator(from.charCodeAt(i))) { if (out.length === 0) out += ".."; else out += "/.."; } }
if (out.length > 0) return out + to.slice(toStart + lastCommonSep); else { toStart += lastCommonSep; if (isPosixPathSeparator(to.charCodeAt(toStart))) ++toStart; return to.slice(toStart); }}
export function windowsRelative(from: string, to: string): string { assertArgs(from, to);
const fromOrig = windowsResolve(from); const toOrig = windowsResolve(to);
if (fromOrig === toOrig) return "";
from = fromOrig.toLowerCase(); to = toOrig.toLowerCase();
if (from === to) return "";
let fromStart = 0; let fromEnd = from.length; for (; fromStart < fromEnd; ++fromStart) { if (from.charCodeAt(fromStart) !== CHAR_BACKWARD_SLASH) break; } for (; fromEnd - 1 > fromStart; --fromEnd) { if (from.charCodeAt(fromEnd - 1) !== CHAR_BACKWARD_SLASH) break; } const fromLen = fromEnd - fromStart;
let toStart = 0; let toEnd = to.length; for (; toStart < toEnd; ++toStart) { if (to.charCodeAt(toStart) !== CHAR_BACKWARD_SLASH) break; } for (; toEnd - 1 > toStart; --toEnd) { if (to.charCodeAt(toEnd - 1) !== CHAR_BACKWARD_SLASH) break; } const toLen = toEnd - toStart;
const length = fromLen < toLen ? fromLen : toLen; let lastCommonSep = -1; let i = 0; for (; i <= length; ++i) { if (i === length) { if (toLen > length) { if (to.charCodeAt(toStart + i) === CHAR_BACKWARD_SLASH) { return toOrig.slice(toStart + i + 1); } else if (i === 2) { return toOrig.slice(toStart + i); } } if (fromLen > length) { if (from.charCodeAt(fromStart + i) === CHAR_BACKWARD_SLASH) { lastCommonSep = i; } else if (i === 2) { lastCommonSep = 3; } } break; } const fromCode = from.charCodeAt(fromStart + i); const toCode = to.charCodeAt(toStart + i); if (fromCode !== toCode) break; else if (fromCode === CHAR_BACKWARD_SLASH) lastCommonSep = i; }
if (i !== length && lastCommonSep === -1) { return toOrig; }
let out = ""; if (lastCommonSep === -1) lastCommonSep = 0; for (i = fromStart + lastCommonSep + 1; i <= fromEnd; ++i) { if (i === fromEnd || from.charCodeAt(i) === CHAR_BACKWARD_SLASH) { if (out.length === 0) out += ".."; else out += "\\.."; } }
if (out.length > 0) { return out + toOrig.slice(toStart + lastCommonSep, toEnd); } else { toStart += lastCommonSep; if (toOrig.charCodeAt(toStart) === CHAR_BACKWARD_SLASH) ++toStart; return toOrig.slice(toStart, toEnd); }}