RESPRenderableHelpers.swift

//
// This source file is part of the valkey-swift project
// Copyright (c) 2025 the valkey-swift project authors
//
// See LICENSE.txt for license information
// SPDX-License-Identifier: Apache-2.0
//
import NIOCore

/// Render token if boolean is true
@usableFromInline
package struct RESPPureToken: RESPRenderable {
    @usableFromInline
    let token: String?
    @inlinable
    package init(_ token: String, _ value: Bool) {
        if value {
            self.token = token
        } else {
            self.token = nil
        }
    }
    @inlinable
    package var respEntries: Int {
        self.token != nil ? 1 : 0
    }
    @inlinable
    package func encode(into commandEncoder: inout ValkeyCommandEncoder) {
        self.token.encode(into: &commandEncoder)
    }
}

/// Render token and value if value is not nil
@usableFromInline
package struct RESPWithToken<Value: RESPRenderable>: RESPRenderable {
    @usableFromInline
    let value: Value?
    @usableFromInline
    let token: String

    @inlinable
    package init(_ token: String, _ value: Value?) {
        self.value = value
        self.token = token
    }
    @inlinable
    package var respEntries: Int {
        guard let value = self.value, value.respEntries > 0 else { return 0 }
        return value.respEntries + 1
    }
    @inlinable
    package func encode(into commandEncoder: inout ValkeyCommandEncoder) {
        guard let value, value.respEntries > 0 else {
            return
        }

        self.token.encode(into: &commandEncoder)
        value.encode(into: &commandEncoder)
    }
}

/// Render array with token preceding each item
@usableFromInline
package struct RESPArrayWithToken<Element: RESPRenderable>: RESPRenderable {
    @usableFromInline
    let array: [Element]
    @usableFromInline
    let token: String

    @inlinable
    package init(_ token: String, _ array: [Element]) {
        self.array = array
        self.token = token
    }
    @inlinable
    package var respEntries: Int {
        self.array.respEntries + self.array.count
    }
    @inlinable
    package func encode(into commandEncoder: inout ValkeyCommandEncoder) {
        for element in self.array {
            token.encode(into: &commandEncoder)
            element.encode(into: &commandEncoder)
        }
    }
}

/// Render array item count and then array
@usableFromInline
package struct RESPArrayWithCount<Element: RESPRenderable>: RESPRenderable {
    @usableFromInline
    let array: [Element]

    @inlinable
    package init(_ array: [Element]) {
        self.array = array
    }
    @inlinable
    package var respEntries: Int {
        self.array.respEntries + 1
    }
    @inlinable
    package func encode(into commandEncoder: inout ValkeyCommandEncoder) {
        self.array.count.encode(into: &commandEncoder)
        self.array.encode(into: &commandEncoder)
    }
}

/// Render number of resp parameters array generates and then array
@usableFromInline
package struct RESPArrayWithParameterCount<Element: RESPRenderable>: RESPRenderable {
    @usableFromInline
    let array: [Element]

    @inlinable
    package init(_ array: [Element]) {
        self.array = array
    }
    @inlinable
    package var respEntries: Int {
        self.array.respEntries + 1
    }
    @inlinable
    package func encode(into commandEncoder: inout ValkeyCommandEncoder) {
        self.array.respEntries.encode(into: &commandEncoder)
        self.array.encode(into: &commandEncoder)
    }
}

/// Render token, count of items in array and array, but only if array is non-empty
@usableFromInline
package struct RESPArrayWithTokenAndCount<Element: RESPRenderable>: RESPRenderable {
    @usableFromInline
    let array: [Element]
    @usableFromInline
    let token: String

    @inlinable
    package init(_ token: String, _ array: [Element]) {
        self.token = token
        self.array = array
    }

    @inlinable
    package var respEntries: Int {
        guard self.array.count > 0 else { return 0 }
        return self.array.respEntries + 2
    }
    @inlinable
    package func encode(into commandEncoder: inout ValkeyCommandEncoder) {
        guard self.array.count > 0 else { return }
        self.token.encode(into: &commandEncoder)
        self.array.count.encode(into: &commandEncoder)
        self.array.encode(into: &commandEncoder)
    }
}

/// Render token, count of parameters generated by array and array, but only if array is non-empty
@usableFromInline
package struct RESPArrayWithTokenAndParameterCount<Element: RESPRenderable>: RESPRenderable {
    @usableFromInline
    let array: [Element]
    @usableFromInline
    let token: String

    @inlinable
    package init(_ token: String, _ array: [Element]) {
        self.token = token
        self.array = array
    }
    @inlinable
    package var respEntries: Int {
        let respEntries = self.array.respEntries
        guard respEntries > 0 else { return 0 }
        return respEntries + 2
    }
    @inlinable
    package func encode(into commandEncoder: inout ValkeyCommandEncoder) {
        let respEntries = self.array.respEntries
        guard respEntries > 0 else { return }
        self.token.encode(into: &commandEncoder)
        respEntries.encode(into: &commandEncoder)
        self.array.encode(into: &commandEncoder)
    }
}