zig/lib/std/http.zig

const std = @import("std.zig");

pub const Client = @import("http/Client.zig");
pub const Server = @import("http/Server.zig");
pub const protocol = @import("http/protocol.zig");
const headers = @import("http/Headers.zig");

pub const Headers = headers.Headers;
pub const Field = headers.Field;

pub const Version = enum {
    @"HTTP/1.0",
    @"HTTP/1.1",
};

/// https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods
///
/// https://datatracker.ietf.org/doc/html/rfc7231#section-4 Initial definition
///
/// https://datatracker.ietf.org/doc/html/rfc5789#section-2 PATCH
pub const Method = enum(u64) { // TODO: should be u192 or u256, but neither is supported by the C backend, and therefore cannot pass CI
    GET = parse("GET"),
    HEAD = parse("HEAD"),
    POST = parse("POST"),
    PUT = parse("PUT"),
    DELETE = parse("DELETE"),
    CONNECT = parse("CONNECT"),
    OPTIONS = parse("OPTIONS"),
    TRACE = parse("TRACE"),
    PATCH = parse("PATCH"),

    _,

    /// Converts `s` into a type that may be used as a `Method` field.
    /// Asserts that `s` is 24 or fewer bytes.
    pub fn parse(s: []const u8) u64 {
        var x: u64 = 0;
        @memcpy(std.mem.asBytes(&x)[0..s.len], s);
        return x;
    }

    pub fn write(self: Method, w: anytype) !void {
        const bytes = std.mem.asBytes(&@intFromEnum(self));
        const str = std.mem.sliceTo(bytes, 0);
        try w.writeAll(str);
    }

    pub fn format(value: Method, comptime _: []const u8, _: std.fmt.FormatOptions, writer: anytype) @TypeOf(writer).Error!void {
        return try value.write(writer);
    }

    /// Returns true if a request of this method is allowed to have a body
    /// Actual behavior from servers may vary and should still be checked
    pub fn requestHasBody(self: Method) bool {
        return switch (self) {
            .POST, .PUT, .PATCH => true,
            .GET, .HEAD, .DELETE, .CONNECT, .OPTIONS, .TRACE => false,
            else => true,
        };
    }

    /// Returns true if a response to this method is allowed to have a body
    /// Actual behavior from clients may vary and should still be checked
    pub fn responseHasBody(self: Method) bool {
        return switch (self) {
            .GET, .POST, .DELETE, .CONNECT, .OPTIONS, .PATCH => true,
            .HEAD, .PUT, .TRACE => false,
            else => true,
        };
    }

    /// An HTTP method is safe if it doesn't alter the state of the server.
    ///
    /// https://developer.mozilla.org/en-US/docs/Glossary/Safe/HTTP
    ///
    /// https://datatracker.ietf.org/doc/html/rfc7231#section-4.2.1
    pub fn safe(self: Method) bool {
        return switch (self) {
            .GET, .HEAD, .OPTIONS, .TRACE => true,
            .POST, .PUT, .DELETE, .CONNECT, .PATCH => false,
            else => false,
        };
    }

    /// An HTTP method is idempotent if an identical request can be made once or several times in a row with the same effect while leaving the server in the same state.
    ///
    /// https://developer.mozilla.org/en-US/docs/Glossary/Idempotent
    ///
    /// https://datatracker.ietf.org/doc/html/rfc7231#section-4.2.2
    pub fn idempotent(self: Method) bool {
        return switch (self) {
            .GET, .HEAD, .PUT, .DELETE, .OPTIONS, .TRACE => true,
            .CONNECT, .POST, .PATCH => false,
            else => false,
        };
    }

    /// A cacheable response is an HTTP response that can be cached, that is stored to be retrieved and used later, saving a new request to the server.
    ///
    /// https://developer.mozilla.org/en-US/docs/Glossary/cacheable
    ///
    /// https://datatracker.ietf.org/doc/html/rfc7231#section-4.2.3
    pub fn cacheable(self: Method) bool {
        return switch (self) {
            .GET, .HEAD => true,
            .POST, .PUT, .DELETE, .CONNECT, .OPTIONS, .TRACE, .PATCH => false,
            else => false,
        };
    }
};

/// https://developer.mozilla.org/en-US/docs/Web/HTTP/Status
pub const Status = enum(u10) {
    @"continue" = 100, // RFC7231, Section 6.2.1
    switching_protocols = 101, // RFC7231, Section 6.2.2
    processing = 102, // RFC2518
    early_hints = 103, // RFC8297

    ok = 200, // RFC7231, Section 6.3.1
    created = 201, // RFC7231, Section 6.3.2
    accepted = 202, // RFC7231, Section 6.3.3
    non_authoritative_info = 203, // RFC7231, Section 6.3.4
    no_content = 204, // RFC7231, Section 6.3.5
    reset_content = 205, // RFC7231, Section 6.3.6
    partial_content = 206, // RFC7233, Section 4.1
    multi_status = 207, // RFC4918
    already_reported = 208, // RFC5842
    im_used = 226, // RFC3229

    multiple_choice = 300, // RFC7231, Section 6.4.1
    moved_permanently = 301, // RFC7231, Section 6.4.2
    found = 302, // RFC7231, Section 6.4.3
    see_other = 303, // RFC7231, Section 6.4.4
    not_modified = 304, // RFC7232, Section 4.1
    use_proxy = 305, // RFC7231, Section 6.4.5
    temporary_redirect = 307, // RFC7231, Section 6.4.7
    permanent_redirect = 308, // RFC7538

    bad_request = 400, // RFC7231, Section 6.5.1
    unauthorized = 401, // RFC7235, Section 3.1
    payment_required = 402, // RFC7231, Section 6.5.2
    forbidden = 403, // RFC7231, Section 6.5.3
    not_found = 404, // RFC7231, Section 6.5.4
    method_not_allowed = 405, // RFC7231, Section 6.5.5
    not_acceptable = 406, // RFC7231, Section 6.5.6
    proxy_auth_required = 407, // RFC7235, Section 3.2
    request_timeout = 408, // RFC7231, Section 6.5.7
    conflict = 409, // RFC7231, Section 6.5.8
    gone = 410, // RFC7231, Section 6.5.9
    length_required = 411, // RFC7231, Section 6.5.10
    precondition_failed = 412, // RFC7232, Section 4.2][RFC8144, Section 3.2
    payload_too_large = 413, // RFC7231, Section 6.5.11
    uri_too_long = 414, // RFC7231, Section 6.5.12
    unsupported_media_type = 415, // RFC7231, Section 6.5.13][RFC7694, Section 3
    range_not_satisfiable = 416, // RFC7233, Section 4.4
    expectation_failed = 417, // RFC7231, Section 6.5.14
    teapot = 418, // RFC 7168, 2.3.3
    misdirected_request = 421, // RFC7540, Section 9.1.2
    unprocessable_entity = 422, // RFC4918
    locked = 423, // RFC4918
    failed_dependency = 424, // RFC4918
    too_early = 425, // RFC8470
    upgrade_required = 426, // RFC7231, Section 6.5.15
    precondition_required = 428, // RFC6585
    too_many_requests = 429, // RFC6585
    request_header_fields_too_large = 431, // RFC6585
    unavailable_for_legal_reasons = 451, // RFC7725

    internal_server_error = 500, // RFC7231, Section 6.6.1
    not_implemented = 501, // RFC7231, Section 6.6.2
    bad_gateway = 502, // RFC7231, Section 6.6.3
    service_unavailable = 503, // RFC7231, Section 6.6.4
    gateway_timeout = 504, // RFC7231, Section 6.6.5
    http_version_not_supported = 505, // RFC7231, Section 6.6.6
    variant_also_negotiates = 506, // RFC2295
    insufficient_storage = 507, // RFC4918
    loop_detected = 508, // RFC5842
    not_extended = 510, // RFC2774
    network_authentication_required = 511, // RFC6585

    _,

    pub fn phrase(self: Status) ?[]const u8 {
        return switch (self) {
            // 1xx statuses
            .@"continue" => "Continue",
            .switching_protocols => "Switching Protocols",
            .processing => "Processing",
            .early_hints => "Early Hints",

            // 2xx statuses
            .ok => "OK",
            .created => "Created",
            .accepted => "Accepted",
            .non_authoritative_info => "Non-Authoritative Information",
            .no_content => "No Content",
            .reset_content => "Reset Content",
            .partial_content => "Partial Content",
            .multi_status => "Multi-Status",
            .already_reported => "Already Reported",
            .im_used => "IM Used",

            // 3xx statuses
            .multiple_choice => "Multiple Choice",
            .moved_permanently => "Moved Permanently",
            .found => "Found",
            .see_other => "See Other",
            .not_modified => "Not Modified",
            .use_proxy => "Use Proxy",
            .temporary_redirect => "Temporary Redirect",
            .permanent_redirect => "Permanent Redirect",

            // 4xx statuses
            .bad_request => "Bad Request",
            .unauthorized => "Unauthorized",
            .payment_required => "Payment Required",
            .forbidden => "Forbidden",
            .not_found => "Not Found",
            .method_not_allowed => "Method Not Allowed",
            .not_acceptable => "Not Acceptable",
            .proxy_auth_required => "Proxy Authentication Required",
            .request_timeout => "Request Timeout",
            .conflict => "Conflict",
            .gone => "Gone",
            .length_required => "Length Required",
            .precondition_failed => "Precondition Failed",
            .payload_too_large => "Payload Too Large",
            .uri_too_long => "URI Too Long",
            .unsupported_media_type => "Unsupported Media Type",
            .range_not_satisfiable => "Range Not Satisfiable",
            .expectation_failed => "Expectation Failed",
            .teapot => "I'm a teapot",
            .misdirected_request => "Misdirected Request",
            .unprocessable_entity => "Unprocessable Entity",
            .locked => "Locked",
            .failed_dependency => "Failed Dependency",
            .too_early => "Too Early",
            .upgrade_required => "Upgrade Required",
            .precondition_required => "Precondition Required",
            .too_many_requests => "Too Many Requests",
            .request_header_fields_too_large => "Request Header Fields Too Large",
            .unavailable_for_legal_reasons => "Unavailable For Legal Reasons",

            // 5xx statuses
            .internal_server_error => "Internal Server Error",
            .not_implemented => "Not Implemented",
            .bad_gateway => "Bad Gateway",
            .service_unavailable => "Service Unavailable",
            .gateway_timeout => "Gateway Timeout",
            .http_version_not_supported => "HTTP Version Not Supported",
            .variant_also_negotiates => "Variant Also Negotiates",
            .insufficient_storage => "Insufficient Storage",
            .loop_detected => "Loop Detected",
            .not_extended => "Not Extended",
            .network_authentication_required => "Network Authentication Required",

            else => return null,
        };
    }

    pub const Class = enum {
        informational,
        success,
        redirect,
        client_error,
        server_error,
    };

    pub fn class(self: Status) Class {
        return switch (@intFromEnum(self)) {
            100...199 => .informational,
            200...299 => .success,
            300...399 => .redirect,
            400...499 => .client_error,
            else => .server_error,
        };
    }

    test {
        try std.testing.expectEqualStrings("OK", Status.ok.phrase().?);
        try std.testing.expectEqualStrings("Not Found", Status.not_found.phrase().?);
    }

    test {
        try std.testing.expectEqual(@as(?Status.Class, Status.Class.success), Status.ok.class());
        try std.testing.expectEqual(@as(?Status.Class, Status.Class.client_error), Status.not_found.class());
    }
};

pub const TransferEncoding = enum {
    chunked,
    // compression is intentionally omitted here, as std.http.Client stores it as content-encoding
};

pub const ContentEncoding = enum {
    identity,
    compress,
    deflate,
    gzip,
    zstd,
};

pub const Connection = enum {
    keep_alive,
    close,
};

test {
    _ = Client;
    _ = Method;
    _ = Server;
    _ = Status;
}