| 1 | package control |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "fmt" |
| 6 | "slices" |
| 7 | "sync" |
| 8 | "time" |
| 9 | |
| 10 | "reasonix/internal/plugin" |
| 11 | "reasonix/internal/tool" |
| 12 | ) |
| 13 | |
| 14 | // mcpManager owns the session's live tool/plugin surface: the MCP plugin Host |
| 15 | // (live server connections), the tool Registry the executor reads each turn, and |
| 16 | // the session-scoped context a hot-added stdio server binds its subprocess to. |
| 17 | // Like approvalManager it holds the live plumbing behind its own lock, off c.mu — |
| 18 | // the Controller keeps the config-facing orchestration (persisting reasonix.toml |
| 19 | // on add/remove, building specs from entries). |
| 20 | // |
| 21 | // mu guards the lazy host creation and host-pointer reads. The registry is |
| 22 | // internally thread-safe (its own RWMutex) and pluginCtx is write-once, so the |
| 23 | // lock is held only briefly — never across the host's network/subprocess I/O. |
| 24 | // host is either injected at construction (the desktop shared-host path) or |
| 25 | // created lazily on the first connect; once set it never reverts to nil. |
| 26 | type mcpManager struct { |
| 27 | mu sync.Mutex |
| 28 | host *plugin.Host |
| 29 | reg *tool.Registry |
| 30 | pluginCtx context.Context |
| 31 | // hostProfile is the fallback surface for lazily created hosts (controllers |
| 32 | // built without an injected one). An injected host's own profile wins. |
| 33 | hostProfile plugin.HostProfile |
| 34 | } |
| 35 | |
| 36 | func newMcpManager(host *plugin.Host, reg *tool.Registry, pluginCtx context.Context, profile plugin.HostProfile) mcpManager { |
| 37 | return mcpManager{host: host, reg: reg, pluginCtx: pluginCtx, hostProfile: profile.Normalize()} |
| 38 | } |
| 39 | |
| 40 | // hostProfileOf returns the live host's profile, or the configured fallback |
| 41 | // when no host exists yet. |
| 42 | func (m *mcpManager) hostProfileOf() plugin.HostProfile { |
| 43 | m.mu.Lock() |
| 44 | host := m.host |
| 45 | profile := m.hostProfile |
| 46 | m.mu.Unlock() |
| 47 | if host != nil { |
| 48 | return host.Profile() |
| 49 | } |
| 50 | return profile.Normalize() |
| 51 | } |
| 52 | |
| 53 | // MCPCapabilityViews returns the host's four-layer capability matrix for MCP |
| 54 | // status surfaces. |
| 55 | func (c *Controller) MCPCapabilityViews() []plugin.CapabilityView { |
| 56 | if host := c.mcp.hostRef(); host != nil { |
| 57 | return host.CapabilityViews() |
| 58 | } |
| 59 | return plugin.NewHostWithProfile(c.mcp.hostProfileOf()).CapabilityViews() |
| 60 | } |
| 61 | |
| 62 | // mcpHostProfile reports the session's MCP capability profile for cache |
| 63 | // identity selection. |
| 64 | func (c *Controller) mcpHostProfile() plugin.HostProfile { return c.mcp.hostProfileOf() } |
| 65 | |
| 66 | // hostRef returns the live plugin host (nil until one is injected or lazily |
| 67 | // created), for the SessionAPI Host() accessor and the nil-safe read wrappers. |
| 68 | func (m *mcpManager) hostRef() *plugin.Host { |
| 69 | m.mu.Lock() |
| 70 | defer m.mu.Unlock() |
| 71 | return m.host |
| 72 | } |
| 73 | |
| 74 | // connectSpec connects (or attaches to an already-connected) MCP server and |
| 75 | // registers its tools, replacing any prior tools under the same prefix. Returns |
| 76 | // the tool count. The host's network/subprocess I/O runs off mu. |
| 77 | func (m *mcpManager) connectSpec(s plugin.Spec) (int, error) { |
| 78 | m.mu.Lock() |
| 79 | if m.host == nil { |
| 80 | m.host = plugin.NewHostWithProfile(m.hostProfile) |
| 81 | } |
| 82 | host, ctx, reg := m.host, m.pluginCtx, m.reg |
| 83 | m.mu.Unlock() |
| 84 | |
| 85 | tools, err := host.Add(ctx, s) |
| 86 | if err != nil { |
| 87 | if !plugin.IsServerAlreadyConnected(err) { |
| 88 | return 0, err |
| 89 | } |
| 90 | toolsCtx, cancel := context.WithTimeout(ctx, 5*time.Second) |
| 91 | defer cancel() |
| 92 | tools, err = host.ToolsFor(toolsCtx, s.Name) |
| 93 | if err != nil { |
| 94 | return 0, err |
| 95 | } |
| 96 | } |
| 97 | if reg != nil { |
| 98 | reg.ResumePrefix(plugin.ToolPrefix(s.Name)) |
| 99 | reg.RemovePrefix(plugin.ToolPrefix(s.Name)) |
| 100 | for _, t := range tools { |
| 101 | reg.Add(t) |
| 102 | } |
| 103 | } |
| 104 | return len(tools), nil |
| 105 | } |
| 106 | |
| 107 | // registerSpecOnDemand restores one enabled server into this session's tool |
| 108 | // registry without starting a disconnected process. A live shared-host client |
| 109 | // is reused immediately; otherwise cached lazy tools (or one connect stub on a |
| 110 | // cache miss) start the server only when the model makes the first real call. |
| 111 | func (m *mcpManager) registerSpecOnDemand(s plugin.Spec) (int, error) { |
| 112 | m.mu.Lock() |
| 113 | if m.host == nil { |
| 114 | m.host = plugin.NewHostWithProfile(m.hostProfile) |
| 115 | } |
| 116 | host, ctx, reg := m.host, m.pluginCtx, m.reg |
| 117 | m.mu.Unlock() |
| 118 | |
| 119 | var tools []tool.Tool |
| 120 | if host.HasClient(s.Name) { |
| 121 | toolsCtx, cancel := context.WithTimeout(ctx, 5*time.Second) |
| 122 | defer cancel() |
| 123 | var err error |
| 124 | tools, err = host.ToolsFor(toolsCtx, s.Name) |
| 125 | if err != nil { |
| 126 | return 0, err |
| 127 | } |
| 128 | } else { |
| 129 | cached, _ := plugin.LoadCachedSchemaForSpecProfile(s, host.Profile()) |
| 130 | tools = plugin.LazyToolset(s, cached, host, reg, ctx, false) |
| 131 | } |
| 132 | if reg != nil { |
| 133 | prefix := plugin.ToolPrefix(s.Name) |
| 134 | reg.ResumePrefix(prefix) |
| 135 | reg.RemovePrefix(prefix) |
| 136 | for _, t := range tools { |
| 137 | reg.Add(t) |
| 138 | } |
| 139 | } |
| 140 | return len(tools), nil |
| 141 | } |
| 142 | |
| 143 | // disconnect drops a live server and its tools from the registry. Reports whether |
| 144 | // a live server was removed. |
| 145 | func (m *mcpManager) disconnect(name string) bool { |
| 146 | host := m.hostRef() |
| 147 | if host == nil { |
| 148 | return false |
| 149 | } |
| 150 | prefix, ok := host.Remove(name) |
| 151 | if ok { |
| 152 | if reg := m.registry(); reg != nil { |
| 153 | reg.RemovePrefix(prefix) |
| 154 | } |
| 155 | } |
| 156 | return ok |
| 157 | } |
| 158 | |
| 159 | // removeToolPrefix drops a server's tools from the registry without touching the |
| 160 | // host — the placeholder / not-connected path. Returns the number removed. |
| 161 | func (m *mcpManager) removeToolPrefix(name string) int { |
| 162 | reg := m.registry() |
| 163 | if reg == nil { |
| 164 | return 0 |
| 165 | } |
| 166 | return reg.RemovePrefix(plugin.ToolPrefix(name)) |
| 167 | } |
| 168 | |
| 169 | // suspendToolPrefix hides a server's tools from this session's registry while a |
| 170 | // shared host keeps the client alive for sibling sessions. |
| 171 | func (m *mcpManager) suspendToolPrefix(name string) bool { |
| 172 | reg := m.registry() |
| 173 | if reg == nil { |
| 174 | return false |
| 175 | } |
| 176 | reg.SuspendPrefix(plugin.ToolPrefix(name)) |
| 177 | return true |
| 178 | } |
| 179 | |
| 180 | // registerTool adds a built-in tool to the live registry (e.g. the slash-command |
| 181 | // tool rebuilt by ReloadCommands). No-op when no registry is bound. |
| 182 | func (m *mcpManager) registerTool(t tool.Tool) { |
| 183 | if reg := m.registry(); reg != nil { |
| 184 | reg.Add(t) |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | // registry returns the shared tool registry under mu (write-once, but read under |
| 189 | // the lock for consistency with the host pointer). |
| 190 | func (m *mcpManager) registry() *tool.Registry { |
| 191 | m.mu.Lock() |
| 192 | defer m.mu.Unlock() |
| 193 | return m.reg |
| 194 | } |
| 195 | |
| 196 | // serverNames lists the live server names (nil when no host is connected). |
| 197 | func (m *mcpManager) serverNames() []string { |
| 198 | if h := m.hostRef(); h != nil { |
| 199 | return h.ServerNames() |
| 200 | } |
| 201 | return nil |
| 202 | } |
| 203 | |
| 204 | // hasServer reports whether a server is live. |
| 205 | func (m *mcpManager) hasServer(name string) bool { |
| 206 | return slices.Contains(m.serverNames(), name) |
| 207 | } |
| 208 | |
| 209 | // prompts lists the live MCP prompts (nil when no host is connected). |
| 210 | func (m *mcpManager) prompts() []plugin.Prompt { |
| 211 | if h := m.hostRef(); h != nil { |
| 212 | return h.Prompts() |
| 213 | } |
| 214 | return nil |
| 215 | } |
| 216 | |
| 217 | // failures lists the recorded MCP startup failures (nil when no host). |
| 218 | func (m *mcpManager) failures() []plugin.Failure { |
| 219 | if h := m.hostRef(); h != nil { |
| 220 | return h.Failures() |
| 221 | } |
| 222 | return nil |
| 223 | } |
| 224 | |
| 225 | // readResource reads an MCP resource. Errors when no host is connected. |
| 226 | func (m *mcpManager) readResource(ctx context.Context, server, uri string) (string, error) { |
| 227 | h := m.hostRef() |
| 228 | if h == nil { |
| 229 | return "", fmt.Errorf("no MCP servers connected") |
| 230 | } |
| 231 | return h.ReadResource(ctx, server, uri) |
| 232 | } |
| 233 |