// FILE: backend/src/db/sequelize.js
// “lazy-load” ตาม env ปลอดภัยกว่า และยังคง dbReady() ให้เรียกทดสอบได้
// ใช้ได้เมื่อจำเป็น (เช่น งาน admin tool เฉพาะกิจ)
// ตั้ง ENABLE_SEQUELIZE=1 เพื่อเปิดใช้ Model loader; ไม่งั้นจะเป็นโหมดเบา ๆ
import { Sequelize } from "sequelize";
import { config } from "../config.js";

export const sequelize = new Sequelize(config.DB.NAME, config.DB.USER, config.DB.PASS, {
    host: config.DB.HOST,
    port: config.DB.PORT,
    dialect: "mariadb",
    logging: false,
    dialectOptions: { timezone: "Z" },
    define: { freezeTableName: true, underscored: false, timestamps: false },
    pool: { max: 10, min: 0, idle: 10000 },
});

// --- 1. ประกาศตัวแปรสำหรับ Export Model ทั้งหมด ---
export let User, Role, Permission, Organization, Project, UserRole, RolePermission, 
    UserProjectRole, Correspondence, CorrespondenceVersion, Document, CorrDocumentMap, 
    Drawing, DrawingRevision, FileObject, RFA, RFARevision, RfaDrawingMap, 
    Transmittal, TransmittalItem, Volume, ContractDwg, SubCategory;

if (process.env.ENABLE_SEQUELIZE === "1") {
    // --- 2. สร้าง Object ของ Models ทั้งหมดที่จะโหลด ---
    const modelsToLoad = {
        User: await import("./models/User.js").catch(() => null),
        Role: await import("./models/Role.js").catch(() => null),
        Permission: await import("./models/Permission.js").catch(() => null),
        Organization: await import("./models/Organization.js").catch(() => null),
        Project: await import("./models/Project.js").catch(() => null),
        UserRole: await import("./models/UserRole.js").catch(() => null),
        RolePermission: await import("./models/RolePermission.js").catch(() => null),
        UserProjectRole: await import("./models/UserProjectRole.js").catch(() => null),
        Correspondence: await import("./models/Correspondence.js").catch(() => null),
        CorrespondenceVersion: await import("./models/CorrespondenceVersion.js").catch(() => null),
        Document: await import("./models/Document.js").catch(() => null),
        CorrDocumentMap: await import("./models/CorrDocumentMap.js").catch(() => null),
        Drawing: await import("./models/Drawing.js").catch(() => null),
        DrawingRevision: await import("./models/DrawingRevision.js").catch(() => null),
        FileObject: await import("./models/FileObject.js").catch(() => null),
        RFA: await import("./models/RFA.js").catch(() => null),
        RFARevision: await import("./models/RFARevision.js").catch(() => null),
        RfaDrawingMap: await import("./models/RfaDrawingMap.js").catch(() => null),
        Transmittal: await import("./models/Transmittal.js").catch(() => null),
        TransmittalItem: await import("./models/TransmittalItem.js").catch(() => null),
        Volume: await import("./models/Volume.js").catch(() => null),
        ContractDwg: await import("./models/ContractDwg.js").catch(() => null),
        SubCategory: await import("./models/SubCategory.js").catch(() => null),
    };

    // --- 3. Initialize Model ทั้งหมด ---
    User = modelsToLoad.User?.default ? modelsToLoad.User.default(sequelize) : null;
    Role = modelsToLoad.Role?.default ? modelsToLoad.Role.default(sequelize) : null;
    Permission = modelsToLoad.Permission?.default ? modelsToLoad.Permission.default(sequelize) : null;
    Organization = modelsToLoad.Organization?.default ? modelsToLoad.Organization.default(sequelize) : null;
    Project = modelsToLoad.Project?.default ? modelsToLoad.Project.default(sequelize) : null;
    UserRole = modelsToLoad.UserRole?.default ? modelsToLoad.UserRole.default(sequelize) : null;
    RolePermission = modelsToLoad.RolePermission?.default ? modelsToLoad.RolePermission.default(sequelize) : null;
    UserProjectRole = modelsToLoad.UserProjectRole?.default ? modelsToLoad.UserProjectRole.default(sequelize) : null;
    Correspondence = modelsToLoad.Correspondence?.default ? modelsToLoad.Correspondence.default(sequelize) : null;
    CorrespondenceVersion = modelsToLoad.CorrespondenceVersion?.default ? modelsToLoad.CorrespondenceVersion.default(sequelize) : null;
    Document = modelsToLoad.Document?.default ? modelsToLoad.Document.default(sequelize) : null;
    CorrDocumentMap = modelsToLoad.CorrDocumentMap?.default ? modelsToLoad.CorrDocumentMap.default(sequelize) : null;
    Drawing = modelsToLoad.Drawing?.default ? modelsToLoad.Drawing.default(sequelize) : null;
    DrawingRevision = modelsToLoad.DrawingRevision?.default ? modelsToLoad.DrawingRevision.default(sequelize) : null;
    FileObject = modelsToLoad.FileObject?.default ? modelsToLoad.FileObject.default(sequelize) : null;
    RFA = modelsToLoad.RFA?.default ? modelsToLoad.RFA.default(sequelize) : null;
    RFARevision = modelsToLoad.RFARevision?.default ? modelsToLoad.RFARevision.default(sequelize) : null;
    RfaDrawingMap = modelsToLoad.RfaDrawingMap?.default ? modelsToLoad.RfaDrawingMap.default(sequelize) : null;
    Transmittal = modelsToLoad.Transmittal?.default ? modelsToLoad.Transmittal.default(sequelize) : null;
    TransmittalItem = modelsToLoad.TransmittalItem?.default ? modelsToLoad.TransmittalItem.default(sequelize) : null;
    Volume = modelsToLoad.Volume?.default ? modelsToLoad.Volume.default(sequelize) : null;
    ContractDwg = modelsToLoad.ContractDwg?.default ? modelsToLoad.ContractDwg.default(sequelize) : null;
    SubCategory = modelsToLoad.SubCategory?.default ? modelsToLoad.SubCategory.default(sequelize) : null;


    // --- 4. สร้างความสัมพันธ์ (Associations) ---
    const loadedModels = { User, Role, Permission, Organization, Project, UserRole, RolePermission, 
        UserProjectRole, Correspondence, CorrespondenceVersion, Document, CorrDocumentMap, 
        Drawing, DrawingRevision, FileObject, RFA, RFARevision, RfaDrawingMap, 
        Transmittal, TransmittalItem, Volume, ContractDwg, SubCategory };
        
    for (const modelName in loadedModels) {
        if (loadedModels[modelName] && loadedModels[modelName].associate) {
            loadedModels[modelName].associate(loadedModels);
        }
    }
}

export async function dbReady() {
    if (process.env.ENABLE_SEQUELIZE !== "1") {
        console.log("Sequelize is disabled.");
        return Promise.resolve();
    }
    try {
        await sequelize.authenticate();
        console.log("Sequelize connection has been established successfully.");
    } catch (error) {
        console.error("Unable to connect to the database via Sequelize:", error);
        return Promise.reject(error);
    }
}