jmap-base-client 0.1.0

// request.rs — JmapRequestBuilder, Session, AccountInfo, WebSocketCapability
//
// Types that belong to the base JMAP client layer (RFC 8620 §2, §3.3, RFC 8887).
// Chat-specific and Mail-specific types live in their own crates.
//
// Types already in jmap-types and NOT redefined here:
//   Id, UTCDate, State, Date, JmapRequest, JmapResponse, Invocation, ResultReference

use std::collections::HashMap;
use std::collections::HashSet;

use serde::Deserialize;

use jmap_types::{Invocation, JmapRequest, State};

use crate::error::ClientError;

// ---------------------------------------------------------------------------
// JmapRequestBuilder (RFC 8620 §3.3)
// ---------------------------------------------------------------------------

/// Fluent builder for multi-method [`JmapRequest`] objects.
///
/// Collects method calls and produces a [`JmapRequest`] ready for dispatch.
///
/// The `using` capability URIs passed to `new` apply to the whole request;
/// callers must include every capability required by the methods they add.
///
/// Spec: RFC 8620 §3.3
#[derive(Debug)]
pub struct JmapRequestBuilder {
    using: Vec<String>,
    method_calls: Vec<Invocation>,
    call_ids: HashSet<String>,
}

impl JmapRequestBuilder {
    /// Create a new builder with the given capability URIs.
    ///
    /// The `using` list MUST include `"urn:ietf:params:jmap:core"` (always
    /// required by RFC 8620 §3.3) plus every capability URI needed by the
    /// methods added via [`add_call`](JmapRequestBuilder::add_call). An
    /// incorrect or empty `using` list will cause the server to return an
    /// `"unknownCapability"` error — the builder does not validate it.
    pub fn new(using: &[&str]) -> Self {
        Self {
            using: using.iter().map(|&s| s.to_owned()).collect(),
            method_calls: Vec::new(),
            call_ids: HashSet::new(),
        }
    }

    /// Add one method call to the request.
    ///
    /// `call_id` must be unique within this request; callers use it to match
    /// responses back to the originating call.
    ///
    /// Returns `Err(ClientError::InvalidArgument)` if `call_id` has already
    /// been used in this builder. Duplicate call IDs violate RFC 8620 §3.5.
    pub fn add_call(
        &mut self,
        method: impl Into<String>,
        args: serde_json::Value,
        call_id: impl Into<String>,
    ) -> Result<&mut Self, ClientError> {
        let call_id = call_id.into();
        if !self.call_ids.insert(call_id.clone()) {
            return Err(ClientError::InvalidArgument(format!(
                "JmapRequestBuilder: duplicate call_id {:?}",
                call_id
            )));
        }
        self.method_calls.push((method.into(), args, call_id));
        Ok(self)
    }

    /// Consume the builder and produce the [`JmapRequest`].
    ///
    /// Returns `Err(ClientError::InvalidArgument)` if no method calls have
    /// been added. An empty `methodCalls` array is invalid per RFC 8620 §3.3.
    pub fn build(self) -> Result<JmapRequest, ClientError> {
        if self.method_calls.is_empty() {
            return Err(ClientError::InvalidArgument("no method calls added".into()));
        }
        Ok(JmapRequest::new(self.using, self.method_calls, None))
    }
}

// ---------------------------------------------------------------------------
// Session (RFC 8620 §2)
// ---------------------------------------------------------------------------

/// JMAP Session object returned by `GET /.well-known/jmap` (RFC 8620 §2).
///
/// Contains only the base RFC 8620 fields. Extension-specific fields
/// (e.g. JMAP Chat `ownerUserId`) are surfaced by extension crates that
/// parse the `capabilities` and `accounts` maps.
#[non_exhaustive]
#[derive(Debug, Clone, PartialEq, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct Session {
    /// Map of capability URI → capability object (RFC 8620 §2).
    ///
    /// Values are kept as raw JSON so callers can extract extension-specific
    /// capability objects without this crate knowing their schema.
    pub capabilities: HashMap<String, serde_json::Value>,

    /// Map of account ID → [`AccountInfo`] (RFC 8620 §2).
    pub accounts: HashMap<String, AccountInfo>,

    /// Map of capability URI → primary account ID (RFC 8620 §2).
    pub primary_accounts: HashMap<String, String>,

    /// Username associated with the current credentials (RFC 8620 §2).
    pub username: String,

    /// URL for JMAP API POST requests (RFC 8620 §2).
    pub api_url: String,

    /// URL template for blob downloads (RFC 8620 §2).
    ///
    /// URI Template (level 1) containing variables `accountId`, `blobId`,
    /// `type`, and `name`.
    pub download_url: String,

    /// URL template for blob uploads (RFC 8620 §2).
    ///
    /// URI Template (level 1) containing variable `accountId`.
    pub upload_url: String,

    /// URL template for SSE push event stream (RFC 8620 §2, §7.3).
    ///
    /// URI Template (level 1) containing variables `types`, `closeafter`,
    /// and `ping`.
    pub event_source_url: String,

    /// Opaque session state token (RFC 8620 §2).
    ///
    /// Changes whenever any session property changes. Returned in every API
    /// response as `sessionState`; clients compare to detect staleness.
    pub state: State,
}

impl Session {
    /// Returns the primary account ID for the given capability URI, if set.
    ///
    /// Example: `session.primary_account_id("urn:ietf:params:jmap:mail")`
    pub fn primary_account_id(&self, capability: &str) -> Option<&str> {
        self.primary_accounts.get(capability).map(String::as_str)
    }

    /// Returns the parsed [`WebSocketCapability`] for the JMAP WebSocket
    /// transport, if advertised (RFC 8887).
    ///
    /// - `Ok(None)` — server does not advertise JMAP WebSocket support.
    /// - `Ok(Some(...))` — WebSocket is supported; use `result.url` to connect.
    /// - `Err` — capability key is present but the value is malformed.
    pub fn websocket_capability(&self) -> Result<Option<WebSocketCapability>, ClientError> {
        let Some(raw) = self.capabilities.get("urn:ietf:params:jmap:websocket") else {
            return Ok(None);
        };
        serde_json::from_value::<WebSocketCapability>(raw.clone())
            .map(Some)
            .map_err(ClientError::Parse)
    }
}

// ---------------------------------------------------------------------------
// AccountInfo (RFC 8620 §2 Account object)
// ---------------------------------------------------------------------------

/// Per-account metadata in a JMAP Session (RFC 8620 §2).
#[non_exhaustive]
#[derive(Debug, Clone, PartialEq, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct AccountInfo {
    /// Human-readable account name (e.g. the owner's email address).
    pub name: String,

    /// `true` if this is the authenticated user's own personal account.
    pub is_personal: bool,

    /// `true` if the entire account is read-only for the current user.
    pub is_read_only: bool,

    /// Map of capability URI → capability object for this account.
    ///
    /// Values are kept as raw JSON so extension crates can extract
    /// their own capability objects.
    pub account_capabilities: HashMap<String, serde_json::Value>,
}

// ---------------------------------------------------------------------------
// WebSocketCapability (RFC 8887)
// ---------------------------------------------------------------------------

/// Capability object for `"urn:ietf:params:jmap:websocket"` (RFC 8887).
///
/// Advertised in `Session.capabilities` when the server supports JMAP over
/// WebSocket. The `url` field is the `wss://` endpoint to connect to.
#[non_exhaustive]
#[derive(Debug, Clone, PartialEq, Eq, Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct WebSocketCapability {
    /// The WebSocket endpoint URL (`wss://`).
    pub url: String,

    /// Whether the server supports push notifications over this WebSocket.
    #[serde(default)]
    pub supports_push: bool,
}

// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------

#[cfg(test)]
mod tests {
    use super::*;
    use serde_json::json;

    // -----------------------------------------------------------------------
    // JmapRequestBuilder
    // -----------------------------------------------------------------------

    /// Oracle: RFC 8620 §3.3 — a request with two method calls serializes to
    /// a JSON object with a "methodCalls" array containing two 3-element arrays.
    /// The expected JSON shape is derived directly from the RFC §3.3 example.
    #[test]
    fn builder_two_calls_serializes_correctly() {
        let mut builder =
            JmapRequestBuilder::new(&["urn:ietf:params:jmap:core", "urn:ietf:params:jmap:mail"]);
        builder
            .add_call(
                "Mailbox/get",
                json!({"accountId": "A13824", "ids": null}),
                "r1",
            )
            .expect("add_call r1 must succeed");
        builder
            .add_call(
                "Email/get",
                json!({"accountId": "A13824", "ids": ["e001"]}),
                "r2",
            )
            .expect("add_call r2 must succeed");
        let req = builder.build().expect("build must succeed with two calls");

        let v = serde_json::to_value(&req).expect("serialize JmapRequest");

        // Oracle: RFC 8620 §3.3 — "using" must be present
        assert!(v.get("using").is_some(), "must have 'using' field");
        let using = v["using"].as_array().expect("using must be array");
        assert_eq!(using.len(), 2);
        assert!(using.contains(&json!("urn:ietf:params:jmap:core")));
        assert!(using.contains(&json!("urn:ietf:params:jmap:mail")));

        // Oracle: RFC 8620 §3.3 — "methodCalls" must be present
        let calls = v["methodCalls"]
            .as_array()
            .expect("methodCalls must be array");
        assert_eq!(calls.len(), 2, "must have exactly 2 method calls");

        // Oracle: RFC 8620 §3.2 — each invocation is [methodName, args, callId]
        assert_eq!(calls[0][0], json!("Mailbox/get"));
        assert_eq!(calls[0][2], json!("r1"));
        assert_eq!(calls[1][0], json!("Email/get"));
        assert_eq!(calls[1][2], json!("r2"));
    }

    /// Oracle: RFC 8620 §3.3 — build() with no method calls is invalid;
    /// must return Err(InvalidArgument) rather than produce an empty batch.
    #[test]
    fn builder_returns_err_on_empty_build() {
        let result = JmapRequestBuilder::new(&["urn:ietf:params:jmap:core"]).build();
        assert!(
            matches!(result, Err(ClientError::InvalidArgument(_))),
            "empty build must return Err(InvalidArgument), got {result:?}"
        );
    }

    /// Oracle: RFC 8620 §3.5 — call IDs must be unique within a request.
    /// Duplicate call ID returns Err(ClientError::InvalidArgument).
    #[test]
    fn builder_returns_err_on_duplicate_call_id() {
        let mut builder = JmapRequestBuilder::new(&["urn:ietf:params:jmap:core"]);
        builder
            .add_call("Foo/get", json!({}), "r1")
            .expect("first add_call must succeed");
        let result = builder.add_call("Bar/get", json!({}), "r1"); // duplicate
        assert!(
            matches!(result, Err(ClientError::InvalidArgument(_))),
            "duplicate call_id must return Err(InvalidArgument), got {result:?}"
        );
    }

    // -----------------------------------------------------------------------
    // Session
    // -----------------------------------------------------------------------

    /// Oracle: RFC 8620 §2.1 example Session JSON, transcribed from the RFC text.
    /// All field names and values come from the RFC, not from the code under test.
    #[test]
    fn session_deserializes_rfc8620_example() {
        // RFC 8620 §2.1 example — hand-transcribed from spec text.
        let raw = r#"{
            "capabilities": {
                "urn:ietf:params:jmap:core": {
                    "maxSizeUpload": 50000000,
                    "maxConcurrentUpload": 8,
                    "maxSizeRequest": 10000000,
                    "maxConcurrentRequest": 8,
                    "maxCallsInRequest": 32,
                    "maxObjectsInGet": 256,
                    "maxObjectsInSet": 128,
                    "collationAlgorithms": [
                        "i;ascii-numeric",
                        "i;ascii-casemap",
                        "i;unicode-casemap"
                    ]
                },
                "urn:ietf:params:jmap:mail": {},
                "urn:ietf:params:jmap:contacts": {},
                "https://example.com/apis/foobar": {
                    "maxFoosFinangled": 42
                }
            },
            "accounts": {
                "A13824": {
                    "name": "john@example.com",
                    "isPersonal": true,
                    "isReadOnly": false,
                    "accountCapabilities": {
                        "urn:ietf:params:jmap:mail": {
                            "maxMailboxesPerEmail": null,
                            "maxMailboxDepth": 10
                        },
                        "urn:ietf:params:jmap:contacts": {}
                    }
                },
                "A97813": {
                    "name": "jane@example.com",
                    "isPersonal": false,
                    "isReadOnly": true,
                    "accountCapabilities": {
                        "urn:ietf:params:jmap:mail": {
                            "maxMailboxesPerEmail": 1,
                            "maxMailboxDepth": 10
                        }
                    }
                }
            },
            "primaryAccounts": {
                "urn:ietf:params:jmap:mail": "A13824",
                "urn:ietf:params:jmap:contacts": "A13824"
            },
            "username": "john@example.com",
            "apiUrl": "https://jmap.example.com/api/",
            "downloadUrl": "https://jmap.example.com/download/{accountId}/{blobId}/{name}?accept={type}",
            "uploadUrl": "https://jmap.example.com/upload/{accountId}/",
            "eventSourceUrl": "https://jmap.example.com/eventsource/?types={types}&closeafter={closeafter}&ping={ping}",
            "state": "75128aab4b1b"
        }"#;

        let session: Session =
            serde_json::from_str(raw).expect("RFC 8620 §2.1 example must deserialize");

        // Oracle: RFC 8620 §2.1
        assert_eq!(session.username, "john@example.com");
        assert_eq!(session.api_url, "https://jmap.example.com/api/");
        assert_eq!(
            session.upload_url,
            "https://jmap.example.com/upload/{accountId}/"
        );
        assert_eq!(
            session.download_url,
            "https://jmap.example.com/download/{accountId}/{blobId}/{name}?accept={type}"
        );
        assert_eq!(
            session.event_source_url,
            "https://jmap.example.com/eventsource/?types={types}&closeafter={closeafter}&ping={ping}"
        );
        assert_eq!(session.state, "75128aab4b1b");

        // Oracle: RFC 8620 §2.1 — capabilities map
        assert!(
            session
                .capabilities
                .contains_key("urn:ietf:params:jmap:core"),
            "must have core capability"
        );
        assert!(
            session
                .capabilities
                .contains_key("urn:ietf:params:jmap:mail"),
            "must have mail capability"
        );
        assert!(
            session
                .capabilities
                .contains_key("https://example.com/apis/foobar"),
            "must have vendor capability"
        );

        // Oracle: RFC 8620 §2.1 — accounts map
        assert!(
            session.accounts.contains_key("A13824"),
            "must have account A13824"
        );
        assert!(
            session.accounts.contains_key("A97813"),
            "must have account A97813"
        );

        // Oracle: RFC 8620 §2.1 — primaryAccounts
        assert_eq!(
            session.primary_account_id("urn:ietf:params:jmap:mail"),
            Some("A13824")
        );
        assert_eq!(
            session.primary_account_id("urn:ietf:params:jmap:contacts"),
            Some("A13824")
        );
        assert_eq!(
            session.primary_account_id("urn:ietf:params:jmap:core"),
            None
        );
    }

    // -----------------------------------------------------------------------
    // AccountInfo
    // -----------------------------------------------------------------------

    /// Oracle: RFC 8620 §2.1 example — account A13824 (john@example.com).
    /// Field names and values transcribed directly from the RFC.
    #[test]
    fn account_info_deserializes_rfc8620_example() {
        // RFC 8620 §2.1 example account entry
        let raw = r#"{
            "name": "john@example.com",
            "isPersonal": true,
            "isReadOnly": false,
            "accountCapabilities": {
                "urn:ietf:params:jmap:mail": {
                    "maxMailboxesPerEmail": null,
                    "maxMailboxDepth": 10
                },
                "urn:ietf:params:jmap:contacts": {}
            }
        }"#;

        let account: AccountInfo =
            serde_json::from_str(raw).expect("RFC 8620 §2.1 AccountInfo must deserialize");

        // Oracle: RFC 8620 §2 Account object fields
        assert_eq!(account.name, "john@example.com");
        assert!(account.is_personal, "isPersonal must be true");
        assert!(!account.is_read_only, "isReadOnly must be false");
        assert!(
            account
                .account_capabilities
                .contains_key("urn:ietf:params:jmap:mail"),
            "must have mail capability"
        );
        assert!(
            account
                .account_capabilities
                .contains_key("urn:ietf:params:jmap:contacts"),
            "must have contacts capability"
        );

        // Oracle: RFC 8620 §2.1 — read-only account (A97813 / jane@example.com)
        let raw2 = r#"{
            "name": "jane@example.com",
            "isPersonal": false,
            "isReadOnly": true,
            "accountCapabilities": {
                "urn:ietf:params:jmap:mail": {
                    "maxMailboxesPerEmail": 1,
                    "maxMailboxDepth": 10
                }
            }
        }"#;
        let account2: AccountInfo = serde_json::from_str(raw2)
            .expect("RFC 8620 §2.1 read-only AccountInfo must deserialize");

        assert_eq!(account2.name, "jane@example.com");
        assert!(!account2.is_personal, "isPersonal must be false");
        assert!(account2.is_read_only, "isReadOnly must be true");
    }

    // -----------------------------------------------------------------------
    // WebSocketCapability
    // -----------------------------------------------------------------------

    /// Oracle: RFC 8887 §3 — WebSocketCapability has url and supportsPush fields.
    /// Transcribed from the RFC 8887 capability object definition.
    #[test]
    fn websocket_capability_deserializes() {
        let raw = r#"{"url": "wss://jmap.example.com/ws", "supportsPush": true}"#;
        let cap: WebSocketCapability =
            serde_json::from_str(raw).expect("WebSocketCapability must deserialize");
        assert_eq!(cap.url, "wss://jmap.example.com/ws");
        assert!(cap.supports_push);
    }

    /// Oracle: RFC 8887 §3 — supportsPush defaults to false when absent.
    #[test]
    fn websocket_capability_supports_push_defaults_false() {
        let raw = r#"{"url": "wss://jmap.example.com/ws"}"#;
        let cap: WebSocketCapability =
            serde_json::from_str(raw).expect("WebSocketCapability must deserialize");
        assert_eq!(cap.url, "wss://jmap.example.com/ws");
        assert!(!cap.supports_push, "supportsPush must default to false");
    }

    /// Oracle: Session.websocket_capability() returns Ok(None) when key absent.
    #[test]
    fn session_websocket_capability_absent_returns_ok_none() {
        let raw = r#"{
            "capabilities": {},
            "accounts": {},
            "primaryAccounts": {},
            "username": "u@example.com",
            "apiUrl": "https://jmap.example.com/api/",
            "downloadUrl": "https://jmap.example.com/dl/{accountId}/{blobId}/{name}?accept={type}",
            "uploadUrl": "https://jmap.example.com/ul/{accountId}/",
            "eventSourceUrl": "https://jmap.example.com/sse/?types={types}&closeafter={closeafter}&ping={ping}",
            "state": "s1"
        }"#;
        let session: Session = serde_json::from_str(raw).expect("Session must deserialize");
        let result = session.websocket_capability();
        assert!(
            matches!(result, Ok(None)),
            "expected Ok(None), got {result:?}"
        );
    }

    /// Oracle: Session.websocket_capability() returns Ok(Some) when key present and valid.
    #[test]
    fn session_websocket_capability_present_and_valid() {
        let raw = r#"{
            "capabilities": {
                "urn:ietf:params:jmap:websocket": {
                    "url": "wss://jmap.example.com/ws",
                    "supportsPush": true
                }
            },
            "accounts": {},
            "primaryAccounts": {},
            "username": "u@example.com",
            "apiUrl": "https://jmap.example.com/api/",
            "downloadUrl": "https://jmap.example.com/dl/{accountId}/{blobId}/{name}?accept={type}",
            "uploadUrl": "https://jmap.example.com/ul/{accountId}/",
            "eventSourceUrl": "https://jmap.example.com/sse/?types={types}&closeafter={closeafter}&ping={ping}",
            "state": "s1"
        }"#;
        let session: Session = serde_json::from_str(raw).expect("Session must deserialize");
        let ws = session
            .websocket_capability()
            .expect("must not error")
            .expect("websocket capability must be present");
        assert_eq!(ws.url, "wss://jmap.example.com/ws");
        assert!(ws.supports_push);
    }
}