import { ErrorCode, McpError } from '@modelcontextprotocol/sdk/types.js';
import { z } from 'zod';
import { getLinearClient } from '../../utils/linear-client.js';
import { defineTool } from '../shared/tool-definition.js';
import type { ProjectMilestone } from '@linear/sdk';
import { mapMilestoneToOutput, getAvailableProjectsJsonForError } from './shared.js';
const ListProjectMilestonesInputSchema = z.object({
projectId: z.string().uuid('Invalid project ID'),
});
export const listProjectMilestonesTool = defineTool({
name: 'list_project_milestones',
description: 'Lists all milestones for a given project.',
inputSchema: ListProjectMilestonesInputSchema.shape,
handler: async ({ projectId }) => {
const linear = getLinearClient();
try {
const project = await linear.project(projectId);
if (!project) {
const availableProjectsJson = await getAvailableProjectsJsonForError(linear);
throw new McpError(
ErrorCode.InvalidParams,
`Project with ID "${projectId}" not found. Valid projects are: ${availableProjectsJson}`,
);
}
const milestonesResult = await project.projectMilestones();
let resultNodes: ProjectMilestone[] = [];
if (milestonesResult && Array.isArray(milestonesResult.nodes)) {
resultNodes = milestonesResult.nodes;
} else if (
milestonesResult &&
typeof milestonesResult === 'object' &&
milestonesResult !== null &&
'nodes' in milestonesResult &&
Array.isArray((milestonesResult as { nodes?: ProjectMilestone[] }).nodes)
) {
resultNodes = (milestonesResult as { nodes: ProjectMilestone[] }).nodes;
} else if (Array.isArray(milestonesResult)) {
resultNodes = milestonesResult as ProjectMilestone[];
} else if (project.name) {
// Project exists but milestonesResult is not in expected format or empty
// This implies no milestones or an unexpected SDK response for milestones
} else {
throw new McpError(
ErrorCode.InternalError,
'Could not retrieve milestones. Project data was inconsistent after initial fetch.',
);
}
return {
content: [
{
type: 'text',
text: JSON.stringify(
resultNodes.map(mapMilestoneToOutput),
),
},
],
};
} catch (error: unknown) {
if (error instanceof McpError) throw error;
const err = error as Error;
if (
err.message.toLowerCase().includes('not found') &&
err.message.toLowerCase().includes(projectId.toLowerCase())
) {
const availableProjectsJson = await getAvailableProjectsJsonForError(linear);
throw new McpError(
ErrorCode.InvalidParams,
`Project with ID "${projectId}" not found when listing milestones. Valid projects are: ${availableProjectsJson}`,
);
}
throw new McpError(
ErrorCode.InternalError,
`Failed to list project milestones: ${err.message || 'Unknown error'}`,
);
}
},
});
