import * as fs from "fs"
import { describe, it, expect } from "vitest"
import { preprocessTODO, parseTodoFile } from "../../lib/file"


describe("parseTodoFile", () => {
  it("parses full TODO file end-to-end", async () => {
    const todo = await parseTodoFile("tests/_mocks/todo-basic.txt")

    expect(todo.sprints.length).toBe(2)

    expect(todo.issues.length).toBe(2)

    // expect(todo.issues[0].title).toBe("Add streaming parser")
    expect(todo.sprints[0].name).toBe("Sprint Alpha")
  })

  it("works with TODO containing only issues", async () => {
    const todo = await parseTodoFile("tests/_mocks/todo-issues-only.txt")
    expect(todo.sprints.length).toBe(0)
    // expect(todo.issues.length).toBe(1) - skipping for now
  })
})


describe("preprocessTODO", () => {
  it("wraps TODO into MIME and puts sprints first", () => {
    const raw = fs.readFileSync("tests/_mocks/todo-basic.txt", "utf-8")
    const mime = preprocessTODO(raw)

    expect(mime).toContain("MIME-Version: 1.0")
    expect(mime).toContain('Content-Type: multipart/mixed; boundary="ISSUE"')

    const firstPartIndex = mime.indexOf("Content-Type: application/sprints")
    const secondPartIndex = mime.indexOf("Content-Type: application/issue")

    expect(firstPartIndex).toBeLessThan(secondPartIndex)
  })

  it("throws on multiple sprints parts", () => {
    const raw = fs.readFileSync("tests/_mocks/todo-multiple-sprints.txt", "utf-8")
    expect(() => preprocessTODO(raw)).toThrow()
  })

  it("preserves unknown MIME types", () => {
    const raw = `
--ISSUE
Content-Type: application/unknown

Hello world
`
    const mime = preprocessTODO(raw)
    expect(mime).toContain("application/unknown")
  })
})