// loaders.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors
import { ArrowLikeField } from "./arrow-like-field.js";
export class ArrowLikeSchema {
    fields;
    metadata;
    constructor(fields, metadata = new Map()) {
        // checkNames(fields);
        // For kepler fields, create arrow compatible `Fields` that have kepler fields as `metadata`
        this.fields = fields.map((field) => new ArrowLikeField(field.name, field.type, field.nullable, field.metadata));
        this.metadata =
            metadata instanceof Map ? metadata : new Map(Object.entries(metadata));
    }
    // TODO - arrow only seems to compare fields, not metadata
    compareTo(other) {
        if (this.metadata !== other.metadata) {
            return false;
        }
        if (this.fields.length !== other.fields.length) {
            return false;
        }
        for (let i = 0; i < this.fields.length; ++i) {
            if (!this.fields[i].compareTo(other.fields[i])) {
                return false;
            }
        }
        return true;
    }
    select(...columnNames) {
        // Ensure column names reference valid fields
        const nameMap = Object.create(null);
        for (const name of columnNames) {
            nameMap[name] = true;
        }
        const selectedFields = this.fields.filter((field) => nameMap[field.name]);
        return new ArrowLikeSchema(selectedFields, this.metadata);
    }
    selectAt(...columnIndices) {
        // Ensure column indices reference valid fields
        const selectedFields = columnIndices.map((index) => this.fields[index]).filter(Boolean);
        return new ArrowLikeSchema(selectedFields, this.metadata);
    }
    assign(schemaOrFields) {
        let fields;
        let metadata = this.metadata;
        if (schemaOrFields instanceof ArrowLikeSchema) {
            const otherArrowLikeSchema = schemaOrFields;
            fields = otherArrowLikeSchema.fields;
            metadata = mergeMaps(mergeMaps(new Map(), this.metadata), otherArrowLikeSchema.metadata);
        }
        else {
            fields = schemaOrFields;
        }
        // Create a merged list of fields, overwrite fields in place, new fields at end
        const fieldMap = Object.create(null);
        for (const field of this.fields) {
            fieldMap[field.name] = field;
        }
        for (const field of fields) {
            fieldMap[field.name] = field;
        }
        const mergedFields = Object.values(fieldMap);
        return new ArrowLikeSchema(mergedFields, metadata);
    }
}
// Warn if any duplicated field names
// function checkNames(fields: Field[]): void {
//   const usedNames: Record<string, boolean> = {};
//   for (const field of fields) {
//     if (usedNames[field.name]) {
//       // eslint-disable-next-line
//       console.warn('ArrowLikeSchema: duplicated field name', field.name, field);
//     }
//     usedNames[field.name] = true;
//   }
// }
function mergeMaps(m1, m2) {
    // @ts-ignore
    return new Map([...(m1 || new Map()), ...(m2 || new Map())]);
}