import { tokenize, nonWhitespace } from '../parser/lexer';
import { parse } from '../parser/parser';
import { locate } from '../parser/locate';
import type { Situation } from '../parser/types';

// ─── Helper ───────────────────────────────────────────────────────

function situationAt(input: string, offset: number): Situation {
  const rawTokens = tokenize(input);
  const tokens = nonWhitespace(rawTokens);
  const ast = parse(input);
  return locate(offset, tokens);
}

describe('Loki locate', () => {
  // ── IN_SELECTOR_LABEL ──
  it('returns IN_SELECTOR_LABEL for empty {}', () => {
    const s = situationAt('{}', 1);
    expect(s.kind).toBe('IN_SELECTOR_LABEL');
  });

  it('returns IN_SELECTOR_LABEL after opening brace', () => {
    const s = situationAt('{', 1);
    expect(s.kind).toBe('IN_SELECTOR_LABEL');
  });

  it('returns IN_SELECTOR_LABEL after comma in multi-matcher', () => {
    const s = situationAt('{job="nginx", }', 13);
    expect(s.kind).toBe('IN_SELECTOR_LABEL');
  });

  it('returns IN_SELECTOR_LABEL when typing label name', () => {
    const s = situationAt('{j', 2);
    expect(s.kind).toBe('IN_SELECTOR_LABEL');
  });

  // ── IN_SELECTOR_VALUE ──
  it('returns IN_SELECTOR_VALUE after operator', () => {
    const s = situationAt('{job=', 5);
    expect(s.kind).toBe('IN_SELECTOR_VALUE');
    expect(s.labelName).toBe('job');
  });

  it('returns IN_SELECTOR_VALUE after != operator', () => {
    const s = situationAt('{job!=', 6);
    expect(s.kind).toBe('IN_SELECTOR_VALUE');
    expect(s.labelName).toBe('job');
  });

  it('returns IN_SELECTOR_VALUE inside string value', () => {
    const s = situationAt('{job="', 6);
    expect(s.kind).toBe('IN_SELECTOR_VALUE');
    expect(s.labelName).toBe('job');
    expect(s.insideString).toBe(true);
  });

  it('returns IN_SELECTOR_VALUE between quotes', () => {
    const s = situationAt('{job=""}', 6);
    expect(s.kind).toBe('IN_SELECTOR_VALUE');
    expect(s.labelName).toBe('job');
    expect(s.insideString).toBe(true);
  });

  it('returns IN_SELECTOR_VALUE for =~ operator', () => {
    const s = situationAt('{job=~', 6);
    expect(s.kind).toBe('IN_SELECTOR_VALUE');
    expect(s.labelName).toBe('job');
  });

  // ── AFTER_PIPE ──
  it('returns AFTER_PIPE after pipe', () => {
    const s = situationAt('{job="nginx"} | ', 16);
    expect(s.kind).toBe('AFTER_PIPE');
  });

  it('returns IN_SELECTOR_LABEL inside {}', () => {
    const s = situationAt('{}', 1);
    expect(s.kind).toBe('IN_SELECTOR_LABEL');
  });

  // ── IN_FUNCTION_PARENS ──
  it('returns IN_FUNCTION_PARENS inside rate()', () => {
    const s = situationAt('rate(', 5);
    expect(s.kind).toBe('IN_FUNCTION_PARENS');
  });

  it('returns IN_FUNCTION_PARENS inside count_over_time()', () => {
    const s = situationAt('count_over_time(', 16);
    expect(s.kind).toBe('IN_FUNCTION_PARENS');
  });

  it('returns IN_FUNCTION_PARENS at root level', () => {
    const s = situationAt('', 0);
    expect(s.kind).toBe('IN_FUNCTION_PARENS');
  });

  // ── NONE inside range brackets ──
  it('returns NONE inside [5m]', () => {
    const s = situationAt('{job="nginx"}[5m]', 15);
    expect(s.kind).not.toBe('IN_FUNCTION_PARENS');
  });

  it('returns NONE inside []', () => {
    const s = situationAt('rate({job="nginx"}[', 19);
    expect(s.kind).not.toBe('IN_FUNCTION_PARENS');
  });

  it('returns NONE typing range inside brackets', () => {
    const s = situationAt('rate({job="nginx"}[1m', 21);
    expect(s.kind).not.toBe('IN_FUNCTION_PARENS');
  });

  // ── matcherIndex ──
  it('sets matcherIndex for first matcher', () => {
    const s = situationAt('{job=', 5);
    expect(s.matcherIndex).toBe(0);
  });

  it('sets matcherIndex for second matcher', () => {
    const s = situationAt('{job="nginx", app=', 18);
    expect(s.matcherIndex).toBe(1);
  });

  it('sets matcherIndex inside string of second matcher', () => {
    const s = situationAt('{job="nginx", app="', 19);
    expect(s.matcherIndex).toBe(1);
  });

  // ── Prefix ──
  it('uses full identifier as prefix at end of word', () => {
    const s = situationAt('count', 5);
    expect(s.prefix).toBe('count');
  });

  it('uses partial identifier as prefix', () => {
    const s = situationAt('cou', 3);
    expect(s.prefix).toBe('cou');
  });

  // ── RCurly boundary (cursor at `}`) ──
  it('returns IN_SELECTOR_LABEL at RCurly in empty selector { }', () => {
    // { }  — cursor is at `}` but no matcher exists yet
    const s = situationAt('{ }', 2);
    expect(s.kind).toBe('IN_SELECTOR_LABEL');
  });

  it('returns IN_SELECTOR_LABEL at RCurly when label has no operator {job}', () => {
    // {job}  — cursor is at `}`, label name without operator → still building selector
    const s = situationAt('{job}', 4);
    expect(s.kind).toBe('IN_SELECTOR_LABEL');
  });

  it('returns AFTER_PIPE at RCurly with complete matcher {job!="" }', () => {
    // {job!="" }  — space before `}` so RCurly doesn't share String's boundary
    const s = situationAt('{job!="" }', 9);
    expect(s.kind).toBe('AFTER_PIPE');
  });

  it('returns IN_SELECTOR_LABEL at RCurly with incomplete second matcher', () => {
    // {job="nginx", app}  — second matcher has no operator yet
    const s = situationAt('{job="nginx", app}', 17);
    expect(s.kind).toBe('IN_SELECTOR_LABEL');
  });

  it('returns AFTER_PIPE at RCurly with operator present {job!="nginx" }', () => {
    // {job!="nginx" }  — space before `}` avoids boundary conflict; has operator → AFTER_PIPE
    const s = situationAt('{job!="nginx" }', 14);
    expect(s.kind).toBe('AFTER_PIPE');
  });

  it('returns IN_SELECTOR_LABEL at RCurly with only comma separators', () => {
    // {job, app}  — only idents and commas, no operator → still building selector
    const s = situationAt('{job, app}', 9);
    expect(s.kind).toBe('IN_SELECTOR_LABEL');
  });

  // ── Label filter ──
  it('returns IN_LABEL_FILTER after label value comparison', () => {
    const s = situationAt('{job="nginx"} | status >', 24);
    expect(s.kind).toBe('IN_LABEL_FILTER');
  });
});