/**
 * Tests for utils/value-helpers.js
 *
 * These helpers back the settings page's "did the user change this?"
 * detection and its "old → new" change notifications. Broken equality
 * rules cause settings to look unchanged (silent drops) or cause
 * spurious save notifications — both surfaced as real bugs before.
 */

import '@js/utils/value-helpers.js';

const {
    areValuesEqual,
    areObjectsEqual,
    formatPropertyName,
    formatValueForDisplay,
} = window.LdrValueHelpers;

describe('areValuesEqual', () => {
    it('treats null and undefined as interchangeable (symmetric)', () => {
        expect(areValuesEqual(null, null)).toBe(true);
        expect(areValuesEqual(undefined, undefined)).toBe(true);
        expect(areValuesEqual(null, undefined)).toBe(true);
        expect(areValuesEqual(undefined, null)).toBe(true);
    });

    it('returns false when only one side is null/undefined', () => {
        expect(areValuesEqual(null, 0)).toBe(false);
        expect(areValuesEqual(0, null)).toBe(false);
        expect(areValuesEqual(undefined, '')).toBe(false);
        expect(areValuesEqual('', undefined)).toBe(false);
        expect(areValuesEqual(null, false)).toBe(false);
    });

    it('handles primitive equality', () => {
        expect(areValuesEqual(1, 1)).toBe(true);
        expect(areValuesEqual('a', 'a')).toBe(true);
        expect(areValuesEqual(true, true)).toBe(true);
        expect(areValuesEqual(1, 2)).toBe(false);
        expect(areValuesEqual('a', 'b')).toBe(false);
    });

    it('coerces numeric strings to numbers for comparison', () => {
        expect(areValuesEqual(1000, '1000')).toBe(true);
        expect(areValuesEqual('1000', 1000)).toBe(true);
        expect(areValuesEqual(1.5, '1.5')).toBe(true);
        expect(areValuesEqual(1000, '1001')).toBe(false);
    });

    it('returns false for mismatched types other than number/string', () => {
        expect(areValuesEqual(true, 1)).toBe(false);
        expect(areValuesEqual(false, 0)).toBe(false);
        expect(areValuesEqual({}, 'object')).toBe(false);
    });

    it('compares arrays by length then deep equality', () => {
        expect(areValuesEqual([1, 2, 3], [1, 2, 3])).toBe(true);
        expect(areValuesEqual([], [])).toBe(true);
        expect(areValuesEqual([1, 2], [1, 2, 3])).toBe(false);
        expect(areValuesEqual([1, 2, 3], [1, 3, 2])).toBe(false); // order matters
        expect(areValuesEqual([{a: 1}], [{a: 1}])).toBe(true);
    });

    it('compares objects by JSON stringification', () => {
        expect(areValuesEqual({a: 1, b: 2}, {a: 1, b: 2})).toBe(true);
        expect(areValuesEqual({a: 1}, {a: 2})).toBe(false);
        expect(areValuesEqual({}, {})).toBe(true);
    });

    it('does not confuse an array with an equivalent object', () => {
        // [] stringifies as "[]" and {} as "{}", so these differ
        expect(areValuesEqual([], {})).toBe(false);
    });
});

describe('areObjectsEqual', () => {
    it('treats empty objects as equal', () => {
        expect(areObjectsEqual({}, {})).toBe(true);
    });

    it('returns false when key counts differ', () => {
        expect(areObjectsEqual({a: 1}, {a: 1, b: 2})).toBe(false);
        expect(areObjectsEqual({a: 1, b: 2}, {a: 1})).toBe(false);
    });

    it('returns false when a key is missing on the other side', () => {
        expect(areObjectsEqual({a: 1}, {b: 1})).toBe(false);
    });

    it('delegates value comparison to areValuesEqual', () => {
        // Numeric string coercion works via areValuesEqual
        expect(areObjectsEqual({port: 8080}, {port: '8080'})).toBe(true);
    });

    it('recurses through nested objects via areValuesEqual', () => {
        expect(areObjectsEqual(
            {nested: {a: 1, b: [2, 3]}},
            {nested: {a: 1, b: [2, 3]}}
        )).toBe(true);
        expect(areObjectsEqual(
            {nested: {a: 1}},
            {nested: {a: 2}}
        )).toBe(false);
    });
});

describe('formatPropertyName', () => {
    it('converts snake_case to Title Case', () => {
        expect(formatPropertyName('llm_provider')).toBe('Llm Provider');
        expect(formatPropertyName('max_output_tokens')).toBe('Max Output Tokens');
    });

    it('handles a single word', () => {
        expect(formatPropertyName('provider')).toBe('Provider');
    });

    it('handles an already-capitalized word', () => {
        expect(formatPropertyName('Provider')).toBe('Provider');
    });
});

describe('formatValueForDisplay', () => {
    it('returns "empty" for null and undefined', () => {
        expect(formatValueForDisplay(null)).toBe('empty');
        expect(formatValueForDisplay(undefined)).toBe('empty');
    });

    it('returns "enabled"/"disabled" for booleans', () => {
        expect(formatValueForDisplay(true)).toBe('enabled');
        expect(formatValueForDisplay(false)).toBe('disabled');
    });

    it('wraps short strings in quotes', () => {
        expect(formatValueForDisplay('hello')).toBe('"hello"');
        expect(formatValueForDisplay('')).toBe('""');
    });

    it('truncates strings longer than 20 chars', () => {
        const long = 'a'.repeat(25);
        const result = formatValueForDisplay(long);
        expect(result).toBe('"' + 'a'.repeat(18) + '..."');
        expect(result.length).toBeLessThan(long.length + 2);
    });

    it('keeps 20-char strings as-is (boundary)', () => {
        const twenty = 'a'.repeat(20);
        expect(formatValueForDisplay(twenty)).toBe(`"${twenty}"`);
    });

    it('truncates 21-char strings (off-by-one boundary)', () => {
        const twentyOne = 'a'.repeat(21);
        expect(formatValueForDisplay(twentyOne)).toBe('"' + 'a'.repeat(18) + '..."');
    });

    it('shows objects as "{...}"', () => {
        expect(formatValueForDisplay({a: 1})).toBe('{...}');
    });

    it('coerces numbers to their string form', () => {
        expect(formatValueForDisplay(42)).toBe('42');
        expect(formatValueForDisplay(0)).toBe('0');
        expect(formatValueForDisplay(3.14)).toBe('3.14');
    });
});