import { afterEach, describe, expect } from "bun:test"
import { Effect, Exit, Fiber, Layer } from "effect"
import { Agent } from "../../src/agent/agent"
import { Config } from "@/config/config"
import { CrossSpawnSpawner } from "@opencode-ai/core/cross-spawn-spawner"
import { Session } from "@/session/session"
import { MessageV2 } from "../../src/session/message-v2"
import type { SessionPrompt } from "../../src/session/prompt"
import { MessageID, PartID, SessionID } from "../../src/session/schema"
import { ModelID, ProviderID } from "../../src/provider/schema"
import { TaskTool, type TaskPromptOps } from "../../src/tool/task"
import { Truncate } from "@/tool/truncate"
import { ToolRegistry } from "@/tool/registry"
import { disposeAllInstances } from "../fixture/fixture"
import { testEffect } from "../lib/effect"

afterEach(async () => {
  await disposeAllInstances()
})

const ref = {
  providerID: ProviderID.make("test"),
  modelID: ModelID.make("test-model"),
}

const it = testEffect(
  Layer.mergeAll(
    Agent.defaultLayer,
    Config.defaultLayer,
    CrossSpawnSpawner.defaultLayer,
    Session.defaultLayer,
    Truncate.defaultLayer,
    ToolRegistry.defaultLayer,
  ),
)

function defer<T>() {
  let resolve!: (value: T | PromiseLike<T>) => void
  const promise = new Promise<T>((done) => {
    resolve = done
  })
  return { promise, resolve }
}

const seed = Effect.fn("TaskToolTest.seed")(function* (title = "Pinned") {
  const session = yield* Session.Service
  const chat = yield* session.create({ title })
  const user = yield* session.updateMessage({
    id: MessageID.ascending(),
    role: "user",
    sessionID: chat.id,
    agent: "build",
    model: ref,
    time: { created: Date.now() },
  })
  const assistant: MessageV2.Assistant = {
    id: MessageID.ascending(),
    role: "assistant",
    parentID: user.id,
    sessionID: chat.id,
    mode: "build",
    agent: "build",
    cost: 0,
    path: { cwd: "/tmp", root: "/tmp" },
    tokens: { input: 0, output: 0, reasoning: 0, cache: { read: 0, write: 0 } },
    modelID: ref.modelID,
    providerID: ref.providerID,
    time: { created: Date.now() },
  }
  yield* session.updateMessage(assistant)
  return { chat, assistant }
})

function stubOps(opts?: { onPrompt?: (input: SessionPrompt.PromptInput) => void; text?: string }): TaskPromptOps {
  return {
    cancel: () => Effect.void,
    resolvePromptParts: (template) => Effect.succeed([{ type: "text" as const, text: template }]),
    prompt: (input) =>
      Effect.sync(() => {
        opts?.onPrompt?.(input)
        return reply(input, opts?.text ?? "done")
      }),
  }
}

function reply(input: SessionPrompt.PromptInput, text: string): MessageV2.WithParts {
  const id = MessageID.ascending()
  return {
    info: {
      id,
      role: "assistant",
      parentID: input.messageID ?? MessageID.ascending(),
      sessionID: input.sessionID,
      mode: input.agent ?? "general",
      agent: input.agent ?? "general",
      cost: 0,
      path: { cwd: "/tmp", root: "/tmp" },
      tokens: { input: 0, output: 0, reasoning: 0, cache: { read: 0, write: 0 } },
      modelID: input.model?.modelID ?? ref.modelID,
      providerID: input.model?.providerID ?? ref.providerID,
      time: { created: Date.now() },
      finish: "stop",
    },
    parts: [
      {
        id: PartID.ascending(),
        messageID: id,
        sessionID: input.sessionID,
        type: "text",
        text,
      },
    ],
  }
}

describe("tool.task", () => {
  it.instance(
    "description sorts subagents by name and is stable across calls",
    () =>
      Effect.gen(function* () {
        const agent = yield* Agent.Service
        const build = yield* agent.get("build")
        const registry = yield* ToolRegistry.Service
        const get = Effect.fnUntraced(function* () {
          const tools = yield* registry.tools({ ...ref, agent: build })
          return tools.find((tool) => tool.id === TaskTool.id)?.description ?? ""
        })
        const first = yield* get()
        const second = yield* get()

        expect(first).toBe(second)

        const alpha = first.indexOf("- alpha: Alpha agent")
        const explore = first.indexOf("- explore:")
        const general = first.indexOf("- general:")
        const zebra = first.indexOf("- zebra: Zebra agent")

        expect(alpha).toBeGreaterThan(-1)
        expect(explore).toBeGreaterThan(alpha)
        expect(general).toBeGreaterThan(explore)
        expect(zebra).toBeGreaterThan(general)
      }),
    {
      config: {
        agent: {
          zebra: {
            description: "Zebra agent",
            mode: "subagent",
          },
          alpha: {
            description: "Alpha agent",
            mode: "subagent",
          },
        },
      },
    },
  )

  it.instance(
    "description hides denied subagents for the caller",
    () =>
      Effect.gen(function* () {
        const agent = yield* Agent.Service
        const build = yield* agent.get("build")
        const registry = yield* ToolRegistry.Service
        const description =
          (yield* registry.tools({ ...ref, agent: build })).find((tool) => tool.id === TaskTool.id)?.description ?? ""

        expect(description).toContain("- alpha: Alpha agent")
        expect(description).not.toContain("- zebra: Zebra agent")
      }),
    {
      config: {
        permission: {
          task: {
            "*": "allow",
            zebra: "deny",
          },
        },
        agent: {
          zebra: {
            description: "Zebra agent",
            mode: "subagent",
          },
          alpha: {
            description: "Alpha agent",
            mode: "subagent",
          },
        },
      },
    },
  )

  it.instance("execute resumes an existing task session from task_id", () =>
    Effect.gen(function* () {
      const sessions = yield* Session.Service
      const { chat, assistant } = yield* seed()
      const child = yield* sessions.create({ parentID: chat.id, title: "Existing child" })
      const tool = yield* TaskTool
      const def = yield* tool.init()
      let seen: SessionPrompt.PromptInput | undefined
      const promptOps = stubOps({ text: "resumed", onPrompt: (input) => (seen = input) })

      const result = yield* def.execute(
        {
          description: "inspect bug",
          prompt: "look into the cache key path",
          subagent_type: "general",
          task_id: child.id,
        },
        {
          sessionID: chat.id,
          messageID: assistant.id,
          agent: "build",
          abort: new AbortController().signal,
          extra: { promptOps },
          messages: [],
          metadata: () => Effect.void,
          ask: () => Effect.void,
        },
      )

      const kids = yield* sessions.children(chat.id)
      expect(kids).toHaveLength(1)
      expect(kids[0]?.id).toBe(child.id)
      expect(result.metadata.sessionId).toBe(child.id)
      expect(result.output).toContain(`task_id: ${child.id}`)
      expect(seen?.sessionID).toBe(child.id)
    }),
  )

  it.instance("execute asks by default and skips checks when bypassed", () =>
    Effect.gen(function* () {
      const { chat, assistant } = yield* seed()
      const tool = yield* TaskTool
      const def = yield* tool.init()
      const calls: unknown[] = []
      const promptOps = stubOps()

      const exec = (extra?: Record<string, any>) =>
        def.execute(
          {
            description: "inspect bug",
            prompt: "look into the cache key path",
            subagent_type: "general",
          },
          {
            sessionID: chat.id,
            messageID: assistant.id,
            agent: "build",
            abort: new AbortController().signal,
            extra: { promptOps, ...extra },
            messages: [],
            metadata: () => Effect.void,
            ask: (input) =>
              Effect.sync(() => {
                calls.push(input)
              }),
          },
        )

      yield* exec()
      yield* exec({ bypassAgentCheck: true })

      expect(calls).toHaveLength(1)
      expect(calls[0]).toEqual({
        permission: "task",
        patterns: ["general"],
        always: ["*"],
        metadata: {
          description: "inspect bug",
          subagent_type: "general",
        },
      })
    }),
  )

  it.instance("execute cancels child session when abort signal fires", () =>
    Effect.gen(function* () {
      const { chat, assistant } = yield* seed()
      const tool = yield* TaskTool
      const def = yield* tool.init()
      const ready = defer<SessionPrompt.PromptInput>()
      const cancelled = defer<SessionID>()
      const abort = new AbortController()
      const promptOps: TaskPromptOps = {
        cancel: (sessionID) =>
          Effect.sync(() => {
            cancelled.resolve(sessionID)
          }),
        resolvePromptParts: (template) => Effect.succeed([{ type: "text" as const, text: template }]),
        prompt: (input) =>
          Effect.promise(() => {
            ready.resolve(input)
            return cancelled.promise
          }).pipe(Effect.as(reply(input, "cancelled"))),
      }

      const fiber = yield* def
        .execute(
          {
            description: "inspect bug",
            prompt: "look into the cache key path",
            subagent_type: "general",
          },
          {
            sessionID: chat.id,
            messageID: assistant.id,
            agent: "build",
            abort: abort.signal,
            extra: { promptOps },
            messages: [],
            metadata: () => Effect.void,
            ask: () => Effect.void,
          },
        )
        .pipe(Effect.forkChild)

      const input = yield* Effect.promise(() => ready.promise)
      abort.abort()
      expect(yield* Effect.promise(() => cancelled.promise)).toBe(input.sessionID)

      const exit = yield* Fiber.await(fiber)
      expect(Exit.isSuccess(exit)).toBe(true)
    }),
  )

  it.instance("execute creates a child when task_id does not exist", () =>
    Effect.gen(function* () {
      const sessions = yield* Session.Service
      const { chat, assistant } = yield* seed()
      const tool = yield* TaskTool
      const def = yield* tool.init()
      let seen: SessionPrompt.PromptInput | undefined
      const promptOps = stubOps({ text: "created", onPrompt: (input) => (seen = input) })

      const result = yield* def.execute(
        {
          description: "inspect bug",
          prompt: "look into the cache key path",
          subagent_type: "general",
          task_id: "ses_missing",
        },
        {
          sessionID: chat.id,
          messageID: assistant.id,
          agent: "build",
          abort: new AbortController().signal,
          extra: { promptOps },
          messages: [],
          metadata: () => Effect.void,
          ask: () => Effect.void,
        },
      )

      const kids = yield* sessions.children(chat.id)
      expect(kids).toHaveLength(1)
      expect(kids[0]?.id).toBe(result.metadata.sessionId)
      expect(result.metadata.sessionId).not.toBe("ses_missing")
      expect(result.output).toContain(`task_id: ${result.metadata.sessionId}`)
      expect(seen?.sessionID).toBe(result.metadata.sessionId)
    }),
  )

  it.instance(
    "execute shapes child permissions for task, todowrite, and primary tools",
    () =>
      Effect.gen(function* () {
        const sessions = yield* Session.Service
        const { chat, assistant } = yield* seed()
        const tool = yield* TaskTool
        const def = yield* tool.init()
        let seen: SessionPrompt.PromptInput | undefined
        const promptOps = stubOps({ onPrompt: (input) => (seen = input) })

        const result = yield* def.execute(
          {
            description: "inspect bug",
            prompt: "look into the cache key path",
            subagent_type: "reviewer",
          },
          {
            sessionID: chat.id,
            messageID: assistant.id,
            agent: "build",
            abort: new AbortController().signal,
            extra: { promptOps },
            messages: [],
            metadata: () => Effect.void,
            ask: () => Effect.void,
          },
        )

        const child = yield* sessions.get(result.metadata.sessionId)
        expect(child.parentID).toBe(chat.id)
        expect(child.permission).toEqual([
          {
            permission: "todowrite",
            pattern: "*",
            action: "deny",
          },
          {
            permission: "bash",
            pattern: "*",
            action: "allow",
          },
          {
            permission: "read",
            pattern: "*",
            action: "allow",
          },
        ])
        expect(seen?.tools).toEqual({
          todowrite: false,
          bash: false,
          read: false,
        })
      }),
    {
      config: {
        agent: {
          reviewer: {
            mode: "subagent",
            permission: {
              task: "allow",
            },
          },
        },
        experimental: {
          primary_tools: ["bash", "read"],
        },
      },
    },
  )
})
