/**
 * Browser-based UI tests using Puppeteer
 * Tests the actual browser rendering and JavaScript execution of pages
 */

const puppeteer = require('puppeteer');
const AuthHelper = require('./auth_helper');
const { getPuppeteerLaunchOptions } = require('./puppeteer_config');
const fs = require('fs');
const path = require('path');

const DEFAULT_TIMEOUT = 10000;  // Increased for pages with many network requests
const DEFAULT_WAIT = 3000;      // More time for JS to execute

class BrowserTester {
    constructor(baseUrl = 'http://127.0.0.1:5000') {
        this.baseUrl = baseUrl;
        this.browser = null;
        this.page = null;
    }

    async setup() {
        console.log('🚀 Starting browser test session...');
        this.browser = await puppeteer.launch(getPuppeteerLaunchOptions());

        this.page = await this.browser.newPage();
        this.authHelper = new AuthHelper(this.page, this.baseUrl);

        // Listen to console errors
        this.page.on('console', msg => {
            if (msg.type() === 'error') {
                console.log(`  Browser error: ${msg.text()}`);
            }
        });

        // Listen to JavaScript errors
        this.page.on('pageerror', error => {
            console.log(`❌ [JS ERROR] ${error.message}`);
        });

        // Listen to failed requests
        this.page.on('requestfailed', request => {
            const url = request.url();
            const failure = request.failure();
            const error = failure ? failure.errorText : 'Unknown error';
            // Only log for important resources, ignore favicon etc.
            if (!url.includes('favicon') && !url.includes('.ico')) {
                console.log(`🔴 [REQUEST FAILED] ${url} - ${error}`);
            }
        });

        // Listen to 404 responses to identify missing resources
        this.page.on('response', response => {
            if (response.status() === 404) {
                const url = response.url();
                if (!url.includes('favicon') && !url.includes('.ico')) {
                    console.log(`  [404 RESPONSE] ${url}`);
                }
            }
        });

        // Ensure authentication before running tests
        console.log('\n🔐 Ensuring authentication...');
        try {
            await this.authHelper.ensureAuthenticated();
        } catch (error) {
            console.error('❌ Authentication failed:', error.message);
            throw error;
        }
    }

    async teardown() {
        if (this.browser) {
            await this.browser.close();
            console.log('🏁 Browser test session ended');
        }
    }

    async testPage(path, testName, customTests = null) {
        const url = `${this.baseUrl}${path}`;
        console.log(`\n📄 Testing ${testName}: ${url}`);

        try {
            // Skip navigation if already on the target page (avoids ERR_ABORTED from double-navigation)
            const currentPath = new URL(this.page.url()).pathname;
            const targetPath = new URL(url).pathname;
            if (currentPath !== targetPath) {
                await this.page.goto(url, {
                    waitUntil: 'domcontentloaded',  // Don't wait for all network requests
                    timeout: DEFAULT_TIMEOUT
                });
            } else {
                console.log(`  Already on ${testName}, skipping navigation`);
            }

            console.log(`✅ ${testName} loaded successfully`);

            // Wait for JavaScript to execute
            await new Promise(resolve => setTimeout(resolve, DEFAULT_WAIT));

            // Basic checks for all pages
            const basicChecks = await this.page.evaluate(() => {
                return {
                    hasTitle: document.title.length > 0,
                    hasBody: document.body !== null,
                    hasNoJSErrors: !window.hasJavaScriptErrors, // This would need to be set by error handlers
                    bodyVisible: document.body && window.getComputedStyle(document.body).display !== 'none'
                };
            });

            console.log(`🔍 Basic checks for ${testName}:`);
            console.log(`   Has title: ${basicChecks.hasTitle}`);
            console.log(`   Has body: ${basicChecks.hasBody}`);
            console.log(`   Body visible: ${basicChecks.bodyVisible}`);

            // Run custom tests if provided and collect failures
            const failures = [];
            if (customTests) {
                const customFailures = await customTests(this.page);
                if (Array.isArray(customFailures)) {
                    failures.push(...customFailures);
                }
            }

            if (failures.length > 0) {
                return { success: false, error: failures.join('; ') };
            }

            return { success: true, checks: basicChecks };

        } catch (error) {
            console.log(`❌ Error testing ${testName}: ${error.message}`);
            return { success: false, error: error.message };
        }
    }
}

// Custom test functions for specific pages
// Each returns an array of failure strings (empty = all passed)

const metricsPageTests = async (page) => {
    console.log('🧪 Running metrics-specific tests...');
    const failures = [];

    // Check if metrics elements are present
    const metricsChecks = await page.evaluate(() => {
        const loading = document.getElementById('loading');
        const content = document.getElementById('metrics-content');
        const error = document.getElementById('error');
        const totalTokens = document.getElementById('total-tokens');
        const totalResearches = document.getElementById('total-researches');

        return {
            hasLoadingElement: !!loading,
            hasContentElement: !!content,
            hasErrorElement: !!error,
            hasTotalTokens: !!totalTokens,
            hasTotalResearches: !!totalResearches,
            loadingVisible: loading ? window.getComputedStyle(loading).display !== 'none' : false,
            contentVisible: content ? window.getComputedStyle(content).display !== 'none' : false,
            errorVisible: error ? window.getComputedStyle(error).display !== 'none' : false,
            tokenValue: totalTokens ? totalTokens.textContent : 'NOT FOUND',
            researchValue: totalResearches ? totalResearches.textContent : 'NOT FOUND'
        };
    });

    console.log('📊 Metrics page checks:');
    console.log(`   Loading visible: ${metricsChecks.loadingVisible}`);
    console.log(`   Content visible: ${metricsChecks.contentVisible}`);
    console.log(`   Error visible: ${metricsChecks.errorVisible}`);
    console.log(`   Total tokens: ${metricsChecks.tokenValue}`);
    console.log(`   Total researches: ${metricsChecks.researchValue}`);

    // Either content or error element must exist (error state is valid in CI with no data)
    if (!metricsChecks.hasContentElement && !metricsChecks.hasErrorElement) {
        failures.push('Missing both #metrics-content and #error elements');
    }
    if (!metricsChecks.hasTotalTokens) failures.push('Missing #total-tokens element');
    if (!metricsChecks.hasTotalResearches) failures.push('Missing #total-researches element');

    // Take screenshot for debugging
    try {
        const screenshotPath = path.join(__dirname, 'screenshots', 'metrics-test.png');
        await page.screenshot({ path: screenshotPath });
        console.log(`📸 Screenshot saved: ${screenshotPath}`);
    } catch (err) {
        console.log('⚠️ Could not save screenshot:', err.message);
    }

    return failures;
};

const researchPageTests = async (page) => {
    console.log('🧪 Running research page tests...');
    const failures = [];

    const researchChecks = await page.evaluate(() => {
        const queryInput = document.getElementById('query');
        const submitButton = document.querySelector('button[type="submit"]');
        const modeSelection = document.querySelector('.ldr-mode-selection');
        const modeRadios = document.querySelectorAll('input[name="research_mode"]');

        return {
            hasQueryInput: !!queryInput,
            hasSubmitButton: !!submitButton,
            hasModeSelection: !!modeSelection,
            modeRadioCount: modeRadios.length,
            queryInputEnabled: queryInput ? !queryInput.disabled : false,
            submitButtonEnabled: submitButton ? !submitButton.disabled : false
        };
    });

    console.log('🔍 Research page checks:');
    console.log(`   Has query input: ${researchChecks.hasQueryInput}`);
    console.log(`   Has submit button: ${researchChecks.hasSubmitButton}`);
    console.log(`   Has mode selection: ${researchChecks.hasModeSelection}`);
    console.log(`   Mode radio count: ${researchChecks.modeRadioCount}`);
    console.log(`   Query input enabled: ${researchChecks.queryInputEnabled}`);
    console.log(`   Submit button enabled: ${researchChecks.submitButtonEnabled}`);

    if (!researchChecks.hasQueryInput) failures.push('Missing query input (#query)');
    if (!researchChecks.hasSubmitButton) failures.push('Missing submit button');
    if (!researchChecks.hasModeSelection) failures.push('Missing mode selection (.ldr-mode-selection)');

    // If --search flag is provided, run a test search
    if (process.argv.includes('--search') && researchChecks.hasQueryInput && researchChecks.hasSubmitButton) {
        console.log('\n🔎 Running test search...');
        await page.type('#query', 'Test search query for UI testing');
        console.log('✅ Entered test query');
    }

    return failures;
};

const historyPageTests = async (page) => {
    console.log('🧪 Running history page tests...');
    const failures = [];

    const historyChecks = await page.evaluate(() => {
        const historyContainer = document.getElementById('history-container') ||
                               document.querySelector('.ldr-history-list') ||
                               document.querySelector('[data-testid="history"]');
        const searchInput = document.getElementById('history-search');

        return {
            hasHistoryContainer: !!historyContainer,
            hasSearchInput: !!searchInput,
            historyContainerVisible: historyContainer ? window.getComputedStyle(historyContainer).display !== 'none' : false
        };
    });

    console.log('📜 History page checks:');
    console.log(`   Has history container: ${historyChecks.hasHistoryContainer}`);
    console.log(`   Has search input: ${historyChecks.hasSearchInput}`);
    console.log(`   History container visible: ${historyChecks.historyContainerVisible}`);

    if (!historyChecks.hasHistoryContainer) failures.push('Missing history container');
    if (!historyChecks.hasSearchInput) failures.push('Missing search input (#history-search)');

    return failures;
};

const settingsPageTests = async (page) => {
    console.log('🧪 Running settings page tests...');
    const failures = [];

    const settingsChecks = await page.evaluate(() => {
        const forms = document.querySelectorAll('form');
        const inputs = document.querySelectorAll('input, select, textarea');
        const saveButtons = document.querySelectorAll('button[type="submit"]');
        // Also look for buttons with Save text
        const allButtons = document.querySelectorAll('button');
        const saveTextButtons = Array.from(allButtons).filter(btn =>
            btn.textContent.toLowerCase().includes('save')
        );

        return {
            hasForm: forms.length > 0,
            hasInputs: inputs.length > 0,
            hasSaveButtons: saveButtons.length > 0 || saveTextButtons.length > 0,
            inputCount: inputs.length,
            formCount: forms.length
        };
    });

    console.log('⚙️ Settings page checks:');
    console.log(`   Has forms: ${settingsChecks.hasForm} (${settingsChecks.formCount} forms)`);
    console.log(`   Has inputs: ${settingsChecks.hasInputs} (${settingsChecks.inputCount} inputs)`);
    console.log(`   Has save buttons: ${settingsChecks.hasSaveButtons}`);

    if (!settingsChecks.hasInputs) failures.push('Missing input elements');
    if (!settingsChecks.hasSaveButtons) failures.push('Missing save buttons');

    return failures;
};

// Main test runner
async function runAllTests() {
    const tester = new BrowserTester();

    try {
        await tester.setup();
    } catch (error) {
        console.error('❌ Failed to setup browser:', error.message);
        process.exit(1);
    }

    // Ensure screenshots directory exists
    const screenshotsDir = path.join(__dirname, 'screenshots');
    fs.mkdirSync(screenshotsDir, { recursive: true });

    const results = [];

    // Test main pages
    const testCases = [
        { path: '/', name: 'Home/Research Page', tests: researchPageTests },
        { path: '/metrics/', name: 'Metrics Dashboard', tests: metricsPageTests },
        { path: '/history/', name: 'History Page', tests: historyPageTests },
        { path: '/settings/', name: 'Settings Page', tests: settingsPageTests }
    ];

    for (const testCase of testCases) {
        const result = await tester.testPage(testCase.path, testCase.name, testCase.tests);
        results.push({ ...testCase, result });
    }

    await tester.teardown();

    // Print summary
    console.log('\n' + '='.repeat(50));
    console.log('📋 TEST SUMMARY');
    console.log('='.repeat(50));

    let passCount = 0;
    let failCount = 0;

    results.forEach(({ name, result }) => {
        const status = result.success ? '✅ PASS' : '❌ FAIL';
        console.log(`${status} ${name}`);
        if (!result.success) {
            console.log(`     Error: ${result.error}`);
            failCount++;
        } else {
            passCount++;
        }
    });

    console.log('\n' + '-'.repeat(30));
    console.log(`Total: ${results.length} tests`);
    console.log(`Passed: ${passCount}`);
    console.log(`Failed: ${failCount}`);

    if (failCount === 0) {
        console.log('🎉 All tests passed!');
        process.exit(0);
    } else {
        console.log('💥 Some tests failed!');
        process.exit(1);
    }
}

// Run tests if this file is executed directly
if (require.main === module) {
    runAllTests().catch(error => {
        console.error('💥 Test runner crashed:', error);
        process.exit(1);
    });
}

module.exports = { BrowserTester, runAllTests };
