import { expect, test } from 'vitest';
import type { XOTemplate } from '@xo-cash/types';
import { p2pkhTemplate } from '@xo-cash/templates';
import { TemplateInvalidError, parseTemplate, serializeTemplate } from '../source/index.ts';

/**
 * Tests that parseTemplate accepts a valid XOTemplate object and returns it unchanged.
 */
const testParseTemplateAcceptsValidTemplate = (): void => {
    // Parse the template
    const parsedObjectTemplate: XOTemplate = parseTemplate(p2pkhTemplate);

    // Parse the template from a string
    const parsedStringTemplate = parseTemplate(serializeTemplate(p2pkhTemplate));

    // The parsed template should be equal to the original template
    expect(parsedObjectTemplate).toEqual(p2pkhTemplate);
    expect(parsedStringTemplate).toEqual(p2pkhTemplate);
};

/**
 * Tests that parseTemplate accepts a simple bigint value in a satoshi field and preserves it
 * through the serialize/deserialize round-trip.
 */
const testParseTemplateAcceptsBigintSatoshis = (): void => {
    // Get the first output key
    const firstOutputKey = Object.keys(p2pkhTemplate.outputs)[0];

    if (firstOutputKey === undefined) {
        throw new Error('p2pkhTemplate has no outputs, test fixture is invalid');
    }

    const firstOutput = p2pkhTemplate.outputs[firstOutputKey];

    if (firstOutput === undefined) {
        throw new Error('p2pkhTemplate first output is undefined, test fixture is invalid');
    }

    const templateWithBigint = {
        ...p2pkhTemplate,
        outputs: {
            ...p2pkhTemplate.outputs,
            [firstOutputKey]: { ...firstOutput, valueSatoshis: 1000n },
        },
    };

    // Parse the template
    const parsedTemplate = parseTemplate(templateWithBigint);

    // The parsed template should have the bigint value
    expect(parsedTemplate.outputs[firstOutputKey]!.valueSatoshis).toBe(1000n);
};

/**
 * Tests that parseTemplate preserves bigint precision for values exceeding Number.MAX_SAFE_INTEGER.
 * Uses 2^54 + 1,  so any naive Number conversion in the serialize/deserialize round-trip would produce the wrong value
 * but BigInt conversion would preserve the exact value.
 */
const testParseTemplatePreservesBigintPrecisionBeyondMaxSafeInteger = (): void => {
    // Get the first output key
    const firstOutputKey = Object.keys(p2pkhTemplate.outputs)[0];

    if (firstOutputKey === undefined) {
        throw new Error('p2pkhTemplate has no outputs, test fixture is invalid');
    }

    const firstOutput = p2pkhTemplate.outputs[firstOutputKey];

    if (firstOutput === undefined) {
        throw new Error('p2pkhTemplate first output is undefined, test fixture is invalid');
    }

    const templateWithBigint = {
        ...p2pkhTemplate,
        outputs: {
            ...p2pkhTemplate.outputs,
            [firstOutputKey]: { ...firstOutput, valueSatoshis: 18014398509481985n },
        },
    };

    // Parse the template
    const parsedTemplate = parseTemplate(templateWithBigint);

    // The parsed template should have the exact bigint value
    expect(parsedTemplate.outputs[firstOutputKey]!.valueSatoshis).toBe(18014398509481985n);
};

/**
 * Tests that parseTemplate throws TemplateInvalidError listing all missing required fields
 */
const testParseTemplateThrowsOnMissingRequiredFields = (): void => {
    let thrownError: unknown;

    try {
        parseTemplate({} as XOTemplate);
    } catch (caughtError) {
        thrownError = caughtError;
    }

    const isTemplateInvalidError = thrownError instanceof TemplateInvalidError;
    expect(isTemplateInvalidError).toBe(true);

    const expectedMessage =
        'Template invalid: \n'
        + '- name: expected string, received undefined\n'
        + '- description: expected string, received undefined\n'
        + '- $schema: expected string, received undefined\n'
        + '- supported: expected array, received undefined\n'
        + '- roles: expected record, received undefined\n'
        + '- start: expected array, received undefined\n'
        + '- actions: expected record, received undefined\n'
        + '- inputs: expected record, received undefined\n'
        + '- outputs: expected record, received undefined\n'
        + '- lockingScripts: expected record, received undefined\n'
        + '- scripts: expected record, received undefined';

    expect((thrownError as TemplateInvalidError).message).toBe(expectedMessage);
};

/**
 * Tests that parseTemplate throws TemplateInvalidError naming the exact field path when a
 * single required field is removed from a valid template.
 */
const testParseTemplateThrowsOnMissingScriptsField = (): void => {
    // Set scripts to undefined to test the field path for a missing record
    const templateWithoutScripts = { ...p2pkhTemplate, scripts: undefined };

    let thrownError: unknown;

    try {
        parseTemplate(templateWithoutScripts);
    } catch (caughtError) {
        thrownError = caughtError;
    }

    const isTemplateInvalidError = thrownError instanceof TemplateInvalidError;
    expect(isTemplateInvalidError).toBe(true);

    const expectedMessage = 'Template invalid: \n' + '- scripts: expected record, received undefined';

    expect((thrownError as TemplateInvalidError).message).toBe(expectedMessage);
};

/**
 * Tests that parseTemplate throws TemplateInvalidError reporting both field paths for type violations
 */
const testParseTemplateThrowsOnFieldTypeViolations = (): void => {
    // Replace version with a number and name with a number to produce two simultaneous type errors.

    // @ts-expect-error - version and name are intentionally wrong types for this test case
    const templateWithWrongFieldTypes: XOTemplate = { ...p2pkhTemplate, version: 42, name: 42 };

    let thrownError: unknown;

    try {
        parseTemplate(templateWithWrongFieldTypes);
    } catch (caughtError) {
        thrownError = caughtError;
    }

    const isTemplateInvalidError = thrownError instanceof TemplateInvalidError;
    expect(isTemplateInvalidError).toBe(true);

    const expectedMessage = 'Template invalid: \n' + '- name: expected string, received number\n' + '- version: expected string, received number';

    expect((thrownError as TemplateInvalidError).message).toBe(expectedMessage);
};

/**
 * Tests that parseTemplate throws TemplateInvalidError with the unknown key path for an unrecognized property at the top level
 */
const testParseTemplateThrowsOnUnknownProperties = (): void => {
    const templateWithUnknownProperty = { ...p2pkhTemplate, unknownProperty: 'unexpected' };

    let thrownError: unknown;

    try {
        parseTemplate(templateWithUnknownProperty);
    } catch (caughtError) {
        thrownError = caughtError;
    }

    const isTemplateInvalidError = thrownError instanceof TemplateInvalidError;
    expect(isTemplateInvalidError).toBe(true);

    const expectedMessage = 'Template invalid: \n' + '- (root): Unrecognized key: "unknownProperty"';

    expect((thrownError as TemplateInvalidError).message).toBe(expectedMessage);
};

/**
 * Tests that parseTemplate throws TemplateInvalidError reporting both unrecognized keys for unknown properties nested inside an action definition
 */
const testParseTemplateThrowsOnDeepUnknownProperties = (): void => {
    if (p2pkhTemplate.actions.receive === undefined) {
        throw new Error('p2pkhTemplate has no "receive" action, test fixture is invalid');
    }

    const templateWithDeepUnknown = {
        ...p2pkhTemplate,
        actions: {
            ...p2pkhTemplate.actions,
            receive: { ...p2pkhTemplate.actions.receive, new: 42, new2: 'test' },
        },
    };

    let thrownError: unknown;

    try {
        parseTemplate(templateWithDeepUnknown);
    } catch (caughtError) {
        thrownError = caughtError;
    }

    const isTemplateInvalidError = thrownError instanceof TemplateInvalidError;
    expect(isTemplateInvalidError).toBe(true);

    const expectedMessage = 'Template invalid: \n' + '- actions.receive: Unrecognized keys: "new", "new2"';

    expect((thrownError as TemplateInvalidError).message).toBe(expectedMessage);
};

const runTests = async (): Promise<void> => {
    test('parseTemplate: accepts a valid template', testParseTemplateAcceptsValidTemplate);
    test('parseTemplate: accepts native bigint in satoshi fields', testParseTemplateAcceptsBigintSatoshis);
    test('parseTemplate: preserves bigint precision beyond Number.MAX_SAFE_INTEGER', testParseTemplatePreservesBigintPrecisionBeyondMaxSafeInteger);
    test('parseTemplate: throws TemplateInvalidError on missing required fields', testParseTemplateThrowsOnMissingRequiredFields);
    test('parseTemplate: throws TemplateInvalidError on missing scripts field', testParseTemplateThrowsOnMissingScriptsField);
    test('parseTemplate: throws TemplateInvalidError on field type violations', testParseTemplateThrowsOnFieldTypeViolations);
    test('parseTemplate: throws TemplateInvalidError on unknown top-level property', testParseTemplateThrowsOnUnknownProperties);
    test('parseTemplate: throws TemplateInvalidError on deep unknown properties', testParseTemplateThrowsOnDeepUnknownProperties);
};

await runTests();