browser_mcp/tools_dom.go

package main

import (
	"context"
	"time"

	"github.com/mark3labs/mcp-go/mcp"
	"github.com/mark3labs/mcp-go/server"

	"fn-registry/functions/browser"
)

// registerDomTools wires DOM interaction tools. find/wait stay on under --read-only.
func registerDomTools(s *server.MCPServer, d *deps) {
	s.AddTool(domFindByTextTool(), mcp.NewTypedToolHandler(d.handleDomFindByText))
	s.AddTool(domWaitElementTool(), mcp.NewTypedToolHandler(d.handleDomWaitElement))

	if !d.readOnly {
		s.AddTool(domClickTool(), mcp.NewTypedToolHandler(d.handleDomClick))
		s.AddTool(domClickHumanTool(), mcp.NewTypedToolHandler(d.handleDomClickHuman))
		s.AddTool(domClickTextTool(), mcp.NewTypedToolHandler(d.handleDomClickText))
		s.AddTool(domTypeTool(), mcp.NewTypedToolHandler(d.handleDomType))
	}
}

// ---- dom_click (MUTA) ----

type domClickArgs struct {
	Port     int    `json:"port"`
	Selector string `json:"selector"`
}

func domClickTool() mcp.Tool {
	return mcp.NewTool("dom_click",
		mcp.WithDescription("Click the element matching the CSS selector (synthetic CDP click)."),
		mcp.WithNumber("port", mcp.Description("CDP port. Default 9222.")),
		mcp.WithString("selector", mcp.Required(), mcp.Description("CSS selector of the element to click.")),
	)
}

func (d *deps) handleDomClick(_ context.Context, _ mcp.CallToolRequest, a domClickArgs) (*mcp.CallToolResult, error) {
	if a.Selector == "" {
		return mcp.NewToolResultError("selector is required"), nil
	}
	err := d.withConn(portOr(a.Port), func(c *browser.CDPConn) error {
		return browser.CdpClick(c, a.Selector)
	})
	if err != nil {
		return mcp.NewToolResultError(err.Error()), nil
	}
	return mcp.NewToolResultText("clicked " + a.Selector), nil
}

// ---- dom_click_human (MUTA) ----

type domClickHumanArgs struct {
	Port     int    `json:"port"`
	Selector string `json:"selector"`
}

func domClickHumanTool() mcp.Tool {
	return mcp.NewTool("dom_click_human",
		mcp.WithDescription("Click the element matching the CSS selector with human-like mouse movement (Bézier path + jitter + press/release pause)."),
		mcp.WithNumber("port", mcp.Description("CDP port. Default 9222.")),
		mcp.WithString("selector", mcp.Required(), mcp.Description("CSS selector of the element to click.")),
	)
}

func (d *deps) handleDomClickHuman(_ context.Context, _ mcp.CallToolRequest, a domClickHumanArgs) (*mcp.CallToolResult, error) {
	if a.Selector == "" {
		return mcp.NewToolResultError("selector is required"), nil
	}
	err := d.withConn(portOr(a.Port), func(c *browser.CDPConn) error {
		return browser.CdpClickHuman(c, a.Selector, browser.MouseHumanOpts{})
	})
	if err != nil {
		return mcp.NewToolResultError(err.Error()), nil
	}
	return mcp.NewToolResultText("clicked (human) " + a.Selector), nil
}

// ---- dom_click_text (MUTA) ----

type domClickTextArgs struct {
	Port int    `json:"port"`
	Text string `json:"text"`
}

func domClickTextTool() mcp.Tool {
	return mcp.NewTool("dom_click_text",
		mcp.WithDescription("Find the first element whose visible text matches and click it."),
		mcp.WithNumber("port", mcp.Description("CDP port. Default 9222.")),
		mcp.WithString("text", mcp.Required(), mcp.Description("Visible text to match (substring).")),
	)
}

func (d *deps) handleDomClickText(_ context.Context, _ mcp.CallToolRequest, a domClickTextArgs) (*mcp.CallToolResult, error) {
	if a.Text == "" {
		return mcp.NewToolResultError("text is required"), nil
	}
	err := d.withConn(portOr(a.Port), func(c *browser.CDPConn) error {
		return browser.CdpClickText(c, a.Text, browser.FindByTextOpts{})
	})
	if err != nil {
		return mcp.NewToolResultError(err.Error()), nil
	}
	return mcp.NewToolResultText("clicked text " + a.Text), nil
}

// ---- dom_type (MUTA) ----

type domTypeArgs struct {
	Port int    `json:"port"`
	Text string `json:"text"`
}

func domTypeTool() mcp.Tool {
	return mcp.NewTool("dom_type",
		mcp.WithDescription("Type text into the currently focused element (dispatches key events char by char)."),
		mcp.WithNumber("port", mcp.Description("CDP port. Default 9222.")),
		mcp.WithString("text", mcp.Required(), mcp.Description("Text to type.")),
	)
}

func (d *deps) handleDomType(_ context.Context, _ mcp.CallToolRequest, a domTypeArgs) (*mcp.CallToolResult, error) {
	if a.Text == "" {
		return mcp.NewToolResultError("text is required"), nil
	}
	err := d.withConn(portOr(a.Port), func(c *browser.CDPConn) error {
		return browser.CdpTypeText(c, a.Text)
	})
	if err != nil {
		return mcp.NewToolResultError(err.Error()), nil
	}
	return mcp.NewToolResultText("typed text"), nil
}

// ---- dom_find_by_text ----

type domFindByTextArgs struct {
	Port int    `json:"port"`
	Text string `json:"text"`
}

func domFindByTextTool() mcp.Tool {
	return mcp.NewTool("dom_find_by_text",
		mcp.WithDescription("Find the first element whose visible text matches and return a unique CSS selector for it (empty string if none)."),
		mcp.WithNumber("port", mcp.Description("CDP port. Default 9222.")),
		mcp.WithString("text", mcp.Required(), mcp.Description("Visible text to match (substring).")),
	)
}

func (d *deps) handleDomFindByText(_ context.Context, _ mcp.CallToolRequest, a domFindByTextArgs) (*mcp.CallToolResult, error) {
	if a.Text == "" {
		return mcp.NewToolResultError("text is required"), nil
	}
	var sel string
	err := d.withConn(portOr(a.Port), func(c *browser.CDPConn) error {
		var e error
		sel, e = browser.CdpFindByText(c, a.Text, browser.FindByTextOpts{})
		return e
	})
	if err != nil {
		return mcp.NewToolResultError(err.Error()), nil
	}
	return mcp.NewToolResultText(sel), nil
}

// ---- dom_wait_element ----

type domWaitElementArgs struct {
	Port      int    `json:"port"`
	Selector  string `json:"selector"`
	TimeoutMs int    `json:"timeout_ms"`
}

func domWaitElementTool() mcp.Tool {
	return mcp.NewTool("dom_wait_element",
		mcp.WithDescription("Block until an element matching the CSS selector appears in the DOM (or timeout)."),
		mcp.WithNumber("port", mcp.Description("CDP port. Default 9222.")),
		mcp.WithString("selector", mcp.Required(), mcp.Description("CSS selector to wait for.")),
		mcp.WithNumber("timeout_ms", mcp.Description("Max wait in ms. Default 10000.")),
	)
}

func (d *deps) handleDomWaitElement(_ context.Context, _ mcp.CallToolRequest, a domWaitElementArgs) (*mcp.CallToolResult, error) {
	if a.Selector == "" {
		return mcp.NewToolResultError("selector is required"), nil
	}
	timeout := a.TimeoutMs
	if timeout <= 0 {
		timeout = 10000
	}
	err := d.withConn(portOr(a.Port), func(c *browser.CDPConn) error {
		return browser.CdpWaitElement(c, a.Selector, time.Duration(timeout)*time.Millisecond)
	})
	if err != nil {
		return mcp.NewToolResultError(err.Error()), nil
	}
	return mcp.NewToolResultText("element appeared: " + a.Selector), nil
}