import { McpContext, Resolver, Tool } from '@nestjs-mcp/server';
import { z } from 'zod';
import { TaskStreamApi } from '../api/taskstream-api';
import { issueRef, limit, projectRef, sprintId } from './params';
import { issueLine, sprintLine } from './summaries';
import { toolResult } from './tool-result';

const READ = { readOnlyHint: true, openWorldHint: false } as const;
const WRITE = {
  readOnlyHint: false,
  destructiveHint: false,
  openWorldHint: false,
} as const;

const date = (what: string) => z.string().describe(`${what} (ISO date)`);

@Resolver()
export class SprintsResolver {
  constructor(private readonly api: TaskStreamApi) {}

  @Tool({
    name: 'list_sprints',
    description:
      "A project's sprints (planned, active and closed) with their dates and goal.",
    paramsSchema: z.object({ project: projectRef }),
    annotations: READ,
  })
  list({ project }: { project: string }, ctx: McpContext) {
    return toolResult(async () =>
      (
        await this.api.data(
          this.api.as(ctx).GET('/api/projects/{project}/sprints', {
            params: { path: { project } },
          }),
        )
      ).map(sprintLine),
    );
  }

  @Tool({
    name: 'get_sprint',
    description:
      'A sprint with its progress (tickets and story points finished), its tickets in backlog order and, optionally, the day-by-day burndown.',
    paramsSchema: z.object({
      sprintId,
      withBurndown: z.boolean().default(false),
      limit: limit(200, 100),
    }),
    annotations: READ,
  })
  get(
    params: { sprintId: string; withBurndown: boolean; limit: number },
    ctx: McpContext,
  ) {
    return toolResult(async () => {
      const client = this.api.as(ctx);
      const path = { sprint: params.sprintId };
      const [sprint, progress, issues] = await Promise.all([
        this.api.data(
          client.GET('/api/sprints/{sprint}', { params: { path } }),
        ),
        this.api.data(
          client.GET('/api/sprints/{sprint}/progress', { params: { path } }),
        ),
        this.api.data(
          client.GET('/api/sprints/{sprint}/issues', {
            params: { path, query: { limit: params.limit } },
          }),
        ),
      ]);
      const burndown = params.withBurndown
        ? await this.api.data(
            client.GET('/api/sprints/{sprint}/burndown', { params: { path } }),
          )
        : undefined;
      return {
        ...sprintLine(sprint),
        progress,
        total: issues.total,
        issues: issues.items.map(issueLine),
        burndown,
      };
    });
  }

  @Tool({
    name: 'create_sprint',
    description: 'Plan a sprint in a project (owners and admins).',
    paramsSchema: z.object({
      project: projectRef,
      name: z.string().min(1).max(80).describe('e.g. Sprint 14'),
      goal: z.string().max(500).optional(),
      startDate: date('First day'),
      endDate: date('Last day'),
    }),
    annotations: WRITE,
  })
  create(
    params: {
      project: string;
      name: string;
      goal?: string;
      startDate: string;
      endDate: string;
    },
    ctx: McpContext,
  ) {
    const { project, ...body } = params;
    return toolResult(() =>
      this.api.data(
        this.api.as(ctx).POST('/api/projects/{project}/sprints', {
          params: { path: { project } },
          body,
        }),
      ),
    );
  }

  @Tool({
    name: 'update_sprint',
    description:
      'Rename a sprint, change its goal or its dates (not once closed).',
    paramsSchema: z.object({
      sprintId,
      name: z.string().min(1).max(80).optional(),
      goal: z.string().max(500).nullable().optional(),
      startDate: date('First day').optional(),
      endDate: date('Last day').optional(),
    }),
    annotations: { ...WRITE, idempotentHint: true },
  })
  update(
    params: {
      sprintId: string;
      name?: string;
      goal?: string | null;
      startDate?: string;
      endDate?: string;
    },
    ctx: McpContext,
  ) {
    const { sprintId, ...body } = params;
    return toolResult(() =>
      this.api.data(
        this.api.as(ctx).PATCH('/api/sprints/{sprint}', {
          params: { path: { sprint: sprintId } },
          body,
        }),
      ),
    );
  }

  @Tool({
    name: 'start_sprint',
    description:
      'Start a planned sprint (only one can be under way per project).',
    paramsSchema: z.object({ sprintId }),
    annotations: WRITE,
  })
  start({ sprintId }: { sprintId: string }, ctx: McpContext) {
    return toolResult(() =>
      this.api.data(
        this.api.as(ctx).POST('/api/sprints/{sprint}/start', {
          params: { path: { sprint: sprintId } },
        }),
      ),
    );
  }

  @Tool({
    name: 'close_sprint',
    description:
      'Close the sprint under way. Unfinished tickets move to carryOverTo (another open sprint of the project) or back to the backlog; finished ones stay as its record.',
    paramsSchema: z.object({
      sprintId,
      carryOverTo: z
        .string()
        .nullable()
        .optional()
        .describe('Sprint id for the unfinished tickets; absent: the backlog'),
    }),
    annotations: WRITE,
  })
  close(
    {
      sprintId,
      carryOverTo,
    }: { sprintId: string; carryOverTo?: string | null },
    ctx: McpContext,
  ) {
    return toolResult(() =>
      this.api.data(
        this.api.as(ctx).POST('/api/sprints/{sprint}/close', {
          params: { path: { sprint: sprintId } },
          body: { carryOverTo },
        }),
      ),
    );
  }

  @Tool({
    name: 'delete_sprint',
    description: 'Delete a sprint that never started.',
    paramsSchema: z.object({ sprintId }),
    annotations: { readOnlyHint: false, destructiveHint: true },
  })
  delete({ sprintId }: { sprintId: string }, ctx: McpContext) {
    return toolResult(() =>
      this.api.data(
        this.api.as(ctx).DELETE('/api/sprints/{sprint}', {
          params: { path: { sprint: sprintId } },
        }),
      ),
    );
  }

  @Tool({
    name: 'set_issue_sprint',
    description:
      'Put a ticket in an open sprint of its project, or back to the backlog (null). For many at once: bulk_update_issues.',
    paramsSchema: z.object({
      issue: issueRef,
      sprintId: z.string().nullable().describe('Sprint id, or null'),
    }),
    annotations: { ...WRITE, idempotentHint: true },
  })
  setSprint(
    { issue, sprintId }: { issue: string; sprintId: string | null },
    ctx: McpContext,
  ) {
    return toolResult(() =>
      this.api.data(
        this.api.as(ctx).PUT('/api/issues/{issue}/sprint', {
          params: { path: { issue } },
          body: { sprintId },
        }),
      ),
    );
  }
}