<?php
header('Content-Type: application/json');

require_once __DIR__ . '/config.php';
require_once __DIR__ . '/auth.php';
require_once __DIR__ . '/sheet_helpers.php';

// ---------------------------------------------------------------
// PUBLIC ENDPOINT: create_session
// Must be handled BEFORE the auth guard
// ---------------------------------------------------------------
$action = $_GET['action'] ?? '';

if ($_SERVER['REQUEST_METHOD'] === 'POST' && $action === 'create_session') {
    $input = json_decode(file_get_contents('php://input'), true);
    $idToken = $input['id_token'] ?? '';

    if (empty($idToken)) {
        http_response_code(400);
        echo json_encode(['success' => false, 'message' => 'Missing id_token']);
        exit;
    }

    // Decode JWT payload (middle segment, base64url)
    $parts = explode('.', $idToken);
    if (count($parts) !== 3) {
        http_response_code(400);
        echo json_encode(['success' => false, 'message' => 'Malformed token']);
        exit;
    }

    $payloadJson = base64_decode(strtr($parts[1], '-_', '+/') . str_repeat('=', (4 - strlen($parts[1]) % 4) % 4));
    $payload = json_decode($payloadJson, true);

    if (!$payload) {
        http_response_code(400);
        echo json_encode(['success' => false, 'message' => 'Cannot decode token payload']);
        exit;
    }

    // Validate claims
    $iss = $payload['iss'] ?? '';
    $aud = $payload['aud'] ?? '';
    $exp = $payload['exp'] ?? 0;

    if (strpos($iss, AZURE_TENANT_ID) === false) {
        http_response_code(401);
        echo json_encode(['success' => false, 'message' => 'Invalid issuer']);
        exit;
    }
    if ($aud !== AZURE_CLIENT_ID) {
        http_response_code(401);
        echo json_encode(['success' => false, 'message' => 'Invalid audience']);
        exit;
    }
    if (time() > $exp) {
        http_response_code(401);
        echo json_encode(['success' => false, 'message' => 'Token expired']);
        exit;
    }

    $email = $payload['preferred_username'] ?? $payload['email'] ?? '';
    if (empty($email)) {
        http_response_code(401);
        echo json_encode(['success' => false, 'message' => 'No email claim in token']);
        exit;
    }

    session_regenerate_id(true);
    $_SESSION['user_email'] = strtolower(trim($email));

    echo json_encode(['success' => true]);
    exit;
}

// ---------------------------------------------------------------
// AUTH GUARD — all other actions require a valid session
// ---------------------------------------------------------------
if (empty($_SESSION['user_email'])) {
    http_response_code(401);
    echo json_encode(['success' => false, 'message' => 'Unauthorised']);
    exit;
}

$CURRENT_USER = $_SESSION['user_email'];
$dataFile     = getUserDataFile($CURRENT_USER);
$logFile      = 'activity.log';

// ---------------------------------------------------------------
// LOGOUT (server-side session destroy; client handles MSAL)
// ---------------------------------------------------------------
if ($_SERVER['REQUEST_METHOD'] === 'POST' && $action === 'logout') {
    $_SESSION = [];
    session_destroy();
    echo json_encode(['success' => true]);
    exit;
}

// Helper to log activity
function logActivity($message, $type = 'INFO') {
    global $logFile, $CURRENT_USER;
    $timestamp = date('Y-m-d H:i:s');
    $logEntry = "[$timestamp] [$type] [$CURRENT_USER] $message\n";
    file_put_contents($logFile, $logEntry, FILE_APPEND);
}

// Helper to read data
function getData() {
    global $dataFile;
    if (!file_exists($dataFile)) return [];
    $content = file_get_contents($dataFile);
    return json_decode($content, true) ?? [];
}

// Helper to save data
function saveData($data) {
    global $dataFile;
    file_put_contents($dataFile, json_encode($data, JSON_PRETTY_PRINT));
}

// Helper to generate filename from a row
function generateFilename($item) {
    $omgid = trim($item['OMGID'] ?? '');
    $domain = trim($item['Domain'] ?? '');
    $subteam = trim($item['Subteam'] ?? '');
    $brand = trim($item['Brand'] ?? '');
    $event = trim($item['Event'] ?? '');
    $initiative = trim($item['Initiative'] ?? '');
    $yy = trim($item['YY'] ?? '');
    $seq = trim($item['Sequence'] ?? '');
    $assetName = trim($item['AssetName'] ?? '');
    $version = trim($item['Version'] ?? '');

    if ($domain === 'EVNT') {
        $parts = ['EVNT'];
        if ($event) $parts[] = $event;
        if ($yy) $parts[] = $yy;
        if ($seq) $parts[] = $seq;
        $middle = implode('-', $parts);
    } else {
        $parts = [];
        if ($domain) $parts[] = $domain;
        if ($subteam) $parts[] = $subteam;
        if ($brand) $parts[] = $brand;
        if ($initiative) $parts[] = $initiative;
        if ($yy) $parts[] = $yy;
        if ($seq) $parts[] = $seq;
        $middle = implode('-', $parts);
    }

    $suffix = '';
    if ($assetName) $suffix .= '_' . $assetName;
    if ($version) $suffix .= '_v' . $version;

    if (empty($omgid) && empty($middle)) return '';
    return ($omgid ? $omgid . ' - ' : '') . $middle . $suffix;
}

if ($_SERVER['REQUEST_METHOD'] === 'GET') {
    if ($action === 'load') {
        echo json_encode(getData());
        exit;
    }

    // Sheet Management Endpoints
    if ($action === 'list_sheets') {
        $sheets = getUserSheets($CURRENT_USER);
        echo json_encode(['success' => true, 'sheets' => $sheets]);
        exit;
    }

    if ($action === 'load_sheet') {
        $sheetId = $_GET['id'] ?? '';
        $data = loadSheetData($CURRENT_USER, $sheetId);
        if ($data !== null) {
            echo json_encode(['success' => true, 'data' => $data]);
        } else {
            echo json_encode(['success' => false, 'message' => 'Sheet not found']);
        }
        exit;
    }

    // Load Campaign
    if ($action === 'load_campaign') {
        $name = $_GET['name'] ?? '';
        $file = __DIR__ . '/campaigns/' . preg_replace('/[^a-z0-9_-]/i', '', $name) . '.json';
        if (file_exists($file)) {
            $data = json_decode(file_get_contents($file), true);
            echo json_encode(['success' => true, 'data' => $data]);
        } else {
            echo json_encode(['success' => false, 'message' => 'Campaign not found']);
        }
        exit;
    }
}

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $input = json_decode(file_get_contents('php://input'), true);

    if ($action === 'save') {
        if (isset($input['data']) && is_array($input['data'])) {
            saveData($input['data']);
            echo json_encode(['success' => true]);
        } else {
            echo json_encode(['success' => false, 'message' => 'Invalid data format']);
        }
        exit;
    }

    // Save Campaign
    if ($action === 'save_campaign') {
        $name = preg_replace('/[^a-z0-9_-]/i', '', $input['name'] ?? 'untitled');
        $data = $input['data'] ?? [];
        $file = __DIR__ . '/campaigns/' . $name . '.json';
        if (!is_dir(__DIR__ . '/campaigns/')) {
            mkdir(__DIR__ . '/campaigns/', 0755, true);
        }
        file_put_contents($file, json_encode($data, JSON_PRETTY_PRINT));
        echo json_encode(['success' => true]);
        exit;
    }

    // Sheet Management POST Endpoints
    if ($action === 'save_sheet') {
        $name = $input['name'] ?? '';
        $data = getData();
        $sheet = createSheet($CURRENT_USER, $name, $data);
        echo json_encode(['success' => true, 'sheet' => $sheet]);
        exit;
    }

    if ($action === 'duplicate_sheet') {
        $sheetId = $input['id'] ?? '';
        $sheet = duplicateSheet($CURRENT_USER, $sheetId);
        if ($sheet) {
            echo json_encode(['success' => true, 'sheet' => $sheet]);
        } else {
            echo json_encode(['success' => false, 'message' => 'Failed to duplicate sheet']);
        }
        exit;
    }

    if ($action === 'delete_sheet') {
        $sheetId = $input['id'] ?? '';
        deleteSheet($CURRENT_USER, $sheetId);
        echo json_encode(['success' => true]);
        exit;
    }

    if ($action === 'rename_sheet') {
        $sheetId = $input['id'] ?? '';
        $newName = $input['name'] ?? '';
        $success = renameSheet($CURRENT_USER, $sheetId, $newName);
        echo json_encode(['success' => $success]);
        exit;
    }

    if ($action === 'update_sheet') {
        $data = $input['data'] ?? [];
        saveData($data);
        echo json_encode(['success' => true]);
        exit;
    }

    if ($action === 'command') {
        $data = getData() ?? [];
        $command = trim($input['command']);

        logActivity("Command received: $command", 'COMMAND');

        $commandLower = strtolower($command);

        // Pre-processing: Convert number words to digits
        $numberMap = [
            'one' => '1', 'two' => '2', 'three' => '3', 'four' => '4', 'five' => '5',
            'six' => '6', 'seven' => '7', 'eight' => '8', 'nine' => '9', 'ten' => '10',
            'eleven' => '11', 'twelve' => '12', 'twenty' => '20', 'thirty' => '30'
        ];
        foreach ($numberMap as $word => $digit) {
            $commandLower = preg_replace('/\b' . $word . '\b/', $digit, $commandLower);
        }

        if (isset($GEMINI_API_KEY) && $GEMINI_API_KEY !== 'YOUR_API_KEY_HERE') {

            $currentDate = date('Y-m-d');
            $currentYear2Digit = date('y');
            $dataContext = json_encode($data);
            $yoloMode = isset($input['yolo_mode']) && $input['yolo_mode'] ? 'TRUE' : 'FALSE';
            $conversationHistory = isset($input['history']) ? $input['history'] : '';
            $campaignName = isset($input['campaign_name']) ? trim($input['campaign_name']) : '';

            $globalContext = '';
            if (!empty($campaignName)) {
                $globalContext .= "\nGLOBAL CAMPAIGN NAME: $campaignName";
            }

            $prompt = "
            You are an intelligent assistant managing a JOB NAMING TOOL for Dow Jones.
            Current Date: $currentDate
            YOLO MODE: $yoloMode
            $globalContext

            CONVERSATION HISTORY:
            $conversationHistory

            CURRENT DATA (Context for your actions):
            $dataContext

            === DOW JONES JOB NAMING CONVENTION ===

            FORMAT: [OMGID] - [Domain]-[Subteam]-[Brand]-[Initiative]-[YY]-[Sequence]_[AssetName]_v[Version]
            EVENT FORMAT: [OMGID] - EVNT-[EventAbbrev]-[YY]-[Sequence]_[AssetName]_v[Version]

            EXAMPLES:
            - 000000 - PMKT-ACQ-WSJ-BIC-26-01_MetaBanner_v1
            - 000001 - PMKT-ENGRT-WSJ-BIC-26-01_Email_v1
            - 000002 - EVNT-GFF-26-02_Agenda_v3

            === VALID VALUES ===

            DOMAIN options: PMKT (Performance Marketing), BRND (Brand), EVNT (Event), B2B

            SUBTEAM options (used when Domain is NOT EVNT):
            - ACQ (Acquisition), B2B, CMKT (Content Marketing), ENGRT (Engagement/Retention), ENT (Enterprise)

            BRAND options (used when Domain is NOT EVNT):
            - WSJ (Wall Street Journal), WSJ+ (Wall Street Journal+), BAR (Barron's), MW (MarketWatch)
            - DF (Dragonfly), DJE (Dow Jones Energy), FAC (Factiva), FE (Free Expression)
            - GRI (Global Risk Insights), NWS (Newswires), OA (Oxford Analytica), RSK (Risk), RSKC (Risk Center)
            - DJRJ (Risk Journal), R&C (Risk & Compliance), WECR (World ECR)

            EVENT options (used ONLY when Domain is EVNT, replaces Subteam+Brand):
            - GH (Global Horizons), DJRJS (Risk Journal Summit), WECR (World ECR)
            - FEOE (Free Expressions Opinion Event), FOH (Future of Health), GFF (Global Food Forum)
            - JH (Journal House), TL (TechLive), TLQ (TechLive Qatar), TLCYB (TechLive Cyber), FOE (The Future of Everything)
            - WSJIL (WSJ Invest Live), BODC (Board of Directors Council)
            - CCOC (CCO Council), CEOC (CEO Council), CFOC (CFO Council), CMOC (CMO Council)
            - CPOC (CPO Council), TECC (Technology Council), WSJLI (WSJ Leadership Institute)

            OMGID: 6-digit numeric string (e.g., 000000, 000001)
            YY: 2-digit year (e.g., 26 for 2026). Default to current year: $currentYear2Digit
            Sequence: 2-digit sequence number (e.g., 01, 02, 03)
            Initiative: Free text abbreviation (e.g., BIC, DEMO, LAUNCH)
            AssetName: Descriptive name with no spaces (e.g., MetaBanner, Email, Agenda, LinkedInAd)
            Version: Integer version number (e.g., 1, 2, 3)

            === DATA SCHEMA ===

            Each item has these fields:
            - OMGID (String, 6 digits with leading zeros)
            - Domain (String, one of: PMKT, BRND, EVNT, B2B)
            - Subteam (String, one of: ACQ, B2B, CMKT, ENGRT, ENT) - leave empty for EVNT domain
            - Brand (String, one of the brand abbreviations above) - leave empty for EVNT domain
            - Event (String, one of the event abbreviations above) - ONLY used for EVNT domain, leave empty otherwise
            - Initiative (String, free text)
            - YY (String, 2 digits)
            - Sequence (String, 2 digits with leading zero)
            - AssetName (String, no spaces, PascalCase)
            - Version (String, integer)
            - Filename (Auto-generated, READ-ONLY - DO NOT create this field)

            === SUPPORTED OPERATIONS ===

            1. 'create': Create new job name entries
               Output: { \"operation\": \"create\", \"items\": [ { \"OMGID\": \"000000\", \"Domain\": \"PMKT\", \"Subteam\": \"ACQ\", \"Brand\": \"WSJ\", \"Event\": \"\", \"Initiative\": \"BIC\", \"YY\": \"26\", \"Sequence\": \"01\", \"AssetName\": \"MetaBanner\", \"Version\": \"1\" } ] }

            2. 'update': Update existing entries by OMGID
               Output: { \"operation\": \"update\", \"target_ids\": [\"000000\"], \"values\": { \"Version\": \"2\" } }

            3. 'batch_update': Update multiple items with DIFFERENT values
               Output: { \"operation\": \"batch_update\", \"updates\": [ { \"OMGID\": \"000000\", \"values\": { \"AssetName\": \"LinkedInAd\" } } ] }

            4. 'question': Ask for clarification (ONLY if YOLO MODE is FALSE)
               Output: { \"operation\": \"question\", \"text\": \"What domain is this for?\" }

            === CRITICAL RULES ===

            1. **MULTIPLE ITEMS**: When user says 'create 5 jobs', create 5 separate items in the array. Auto-increment Sequence (01, 02, 03...) and OMGID for each.

            2. **EVENT DOMAIN**: When Domain is EVNT, do NOT populate Subteam or Brand. Use the Event field instead. The user might say the full event name - map it to the abbreviation.

            3. **NON-EVENT DOMAINS**: When Domain is PMKT, BRND, or B2B, populate Subteam and Brand. Leave Event empty.

            4. **OMGID AUTO-INCREMENT**: If user doesn't specify OMGID, look at existing data and auto-increment from the highest existing OMGID. If no data exists, start at 000000.

            5. **SEQUENCE AUTO-INCREMENT**: Within a batch of items sharing the same Domain+Subteam+Brand+Initiative+YY (or Domain+Event+YY for events), auto-increment sequence starting from 01.

            6. **ASSET NAME**: Should be PascalCase with no spaces (e.g., MetaBanner, LinkedInAd, EmailHeader). If user gives a name with spaces, convert it.

            7. **NAME RESOLUTION**: When user says full names, map to abbreviations:
               - 'Performance Marketing' -> PMKT, 'Acquisition' -> ACQ, 'Wall Street Journal' -> WSJ
               - 'Global Food Forum' -> GFF, 'Tech Live' -> TECL, etc.

            8. **YOLO MODE**: If TRUE, NEVER ask questions. Guess missing info:
               - Missing Domain -> PMKT
               - Missing Subteam -> ACQ
               - Missing Brand -> WSJ
               - Missing Initiative -> GEN
               - Missing YY -> $currentYear2Digit
               - Missing AssetName -> Asset
               - Missing Version -> 1

            9. **CLARIFICATION RECOVERY**: User's input may be answering a previous question. Combine with conversation history and EXECUTE.

            10. **CONTEXT**: Use CURRENT DATA to resolve references like 'change all version numbers to 2' or 'update the GFF events'.

            CRITICAL: Respond with ONLY valid JSON. No explanations, no markdown, no conversational text.
            Your response must be a single JSON object starting with { and ending with }.

            User Command: \"$command\"
            ";

            // Call Gemini API
            $url = "https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:generateContent?key=" . $GEMINI_API_KEY;
            $dataPayload = [
                "contents" => [
                    [
                        "parts" => [
                            ["text" => $prompt]
                        ]
                    ]
                ]
            ];

            $ch = curl_init($url);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
            curl_setopt($ch, CURLOPT_POST, true);
            curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($dataPayload));
            curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
            curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

            $response = curl_exec($ch);

            if (curl_errno($ch)) {
                echo json_encode(['success' => false, 'message' => 'Curl error: ' . curl_error($ch)]);
                exit;
            }

            curl_close($ch);

            $responseObj = json_decode($response, true);

            if (isset($responseObj['error'])) {
                $errorMsg = $responseObj['error']['message'] ?? 'Unknown Error';
                logActivity("Gemini API Error: $errorMsg", 'ERROR');
                echo json_encode([
                    'success' => false,
                    'message' => "Gemini API Error: " . $errorMsg,
                    'debug_raw' => $response
                ]);
                exit;
            }

            $llmText = $responseObj['candidates'][0]['content']['parts'][0]['text'] ?? '';

            if (empty($llmText)) {
                 echo json_encode([
                     'success' => false,
                     'message' => "AI returned an empty response.",
                     'debug_raw' => $response
                 ]);
                 exit;
            }

            // Robust JSON Extraction
            $start = strpos($llmText, '{');
            $end = strrpos($llmText, '}');

            if ($start !== false && $end !== false) {
                $responseText = substr($llmText, $start, $end - $start + 1);
            } else {
                $responseText = $llmText;
            }

            $llmAction = json_decode($responseText, true);

            $debugInfo = [
                'debug_llm' => $llmText,
                'debug_extracted' => $responseText,
                'debug_json_error' => json_last_error_msg()
            ];

            if (json_last_error() !== JSON_ERROR_NONE || !$llmAction) {
                 echo json_encode(array_merge([
                     'success' => false,
                     'message' => "Invalid JSON from AI",
                 ], $debugInfo));
                 exit;
            }

            // Execute Action
            if ($llmAction['operation'] === 'create') {
                $newItems = $llmAction['items'];
                $count = 0;
                foreach ($newItems as $item) {
                    if (isset($item['AssetName'])) {
                        $item['AssetName'] = str_replace(' ', '', $item['AssetName']);
                    }
                    $item['Filename'] = generateFilename($item);
                    $data[] = $item;
                    $count++;
                }
                saveData($data);
                logActivity("Created $count job names via AI", 'SUCCESS');
                echo json_encode(array_merge(['success' => true, 'message' => "Created $count job names.", 'count' => $count], $debugInfo));

            } elseif ($llmAction['operation'] === 'update') {
                $updates = $llmAction['values'];
                $targetIds = $llmAction['target_ids'] ?? [];

                $count = 0;
                foreach ($data as &$row) {
                    $match = false;
                    if (!empty($targetIds)) {
                        if (in_array($row['OMGID'] ?? '', $targetIds)) {
                            $match = true;
                        }
                    } else {
                        $match = true;
                    }

                    if ($match) {
                        foreach ($updates as $key => $val) {
                            $row[$key] = $val;
                        }
                        $row['Filename'] = generateFilename($row);
                        $count++;
                    }
                }
                saveData($data);
                logActivity("Updated $count items via AI", 'SUCCESS');
                echo json_encode(array_merge(['success' => true, 'message' => "Updated $count items.", 'count' => $count], $debugInfo));

            } elseif ($llmAction['operation'] === 'batch_update') {
                $updates = $llmAction['updates'];
                $count = 0;
                foreach ($updates as $update) {
                    $id = $update['OMGID'];
                    $values = $update['values'];
                    foreach ($data as &$row) {
                        if (($row['OMGID'] ?? '') === $id) {
                            foreach ($values as $key => $val) {
                                $row[$key] = $val;
                            }
                            $row['Filename'] = generateFilename($row);
                            $count++;
                            break;
                        }
                    }
                }
                saveData($data);
                logActivity("Batch updated $count items via AI", 'SUCCESS');
                echo json_encode(array_merge(['success' => true, 'message' => "Batch updated $count items.", 'count' => $count], $debugInfo));

            } elseif ($llmAction['operation'] === 'question') {
                logActivity("AI asked question: " . $llmAction['text'], 'QUESTION');
                echo json_encode(array_merge(['success' => true, 'question' => $llmAction['text']], $debugInfo));
            } else {
                echo json_encode(array_merge(['success' => false, 'message' => 'Unknown operation: ' . $llmAction['operation']], $debugInfo));
            }
            exit;
        }
    }
}
?>