import type { PluginInput } from "@opencode-ai/plugin"
import { getSessionAgent } from "../../features/claude-code-session-state"
import { log } from "../../shared"

/**
 * Target agents that should receive category+skill reminders.
 * These are orchestrator agents that delegate work to specialized agents.
 */
const TARGET_AGENTS = new Set([
  "sisyphus",
  "sisyphus-junior",
  "atlas",
])

/**
 * Tools that indicate the agent is doing work that could potentially be delegated.
 * When these tools are used, we remind the agent about the category+skill system.
 */
const DELEGATABLE_WORK_TOOLS = new Set([
  "edit",
  "write",
  "bash",
  "read",
  "grep",
  "glob",
])

/**
 * Tools that indicate the agent is already using delegation properly.
 */
const DELEGATION_TOOLS = new Set([
  "delegate_task",
  "call_omo_agent",
  "task",
])

const REMINDER_MESSAGE = `
[Category+Skill Reminder]

You are an orchestrator agent. Consider whether this work should be delegated:

**DELEGATE when:**
- UI/Frontend work → category: "visual-engineering", skills: ["frontend-ui-ux"]
- Complex logic/architecture → category: "ultrabrain"
- Quick/trivial tasks → category: "quick"
- Git operations → skills: ["git-master"]
- Browser automation → skills: ["playwright"] or ["agent-browser"]

**DO IT YOURSELF when:**
- Gathering context/exploring codebase
- Simple edits that are part of a larger task you're coordinating
- Tasks requiring your full context understanding

Example delegation:
\`\`\`
delegate_task(
  category="visual-engineering",
  load_skills=["frontend-ui-ux"],
  description="Implement responsive navbar with animations",
  run_in_background=true
)
\`\`\`
`

interface ToolExecuteInput {
  tool: string
  sessionID: string
  callID: string
  agent?: string
}

interface ToolExecuteOutput {
  title: string
  output: string
  metadata: unknown
}

interface SessionState {
  delegationUsed: boolean
  reminderShown: boolean
  toolCallCount: number
}

export function createCategorySkillReminderHook(_ctx: PluginInput) {
  const sessionStates = new Map<string, SessionState>()

  function getOrCreateState(sessionID: string): SessionState {
    if (!sessionStates.has(sessionID)) {
      sessionStates.set(sessionID, {
        delegationUsed: false,
        reminderShown: false,
        toolCallCount: 0,
      })
    }
    return sessionStates.get(sessionID)!
  }

  function isTargetAgent(sessionID: string, inputAgent?: string): boolean {
    const agent = getSessionAgent(sessionID) ?? inputAgent
    if (!agent) return false
    const agentLower = agent.toLowerCase()
    return TARGET_AGENTS.has(agentLower) || 
           agentLower.includes("sisyphus") || 
           agentLower.includes("atlas")
  }

  const toolExecuteAfter = async (
    input: ToolExecuteInput,
    output: ToolExecuteOutput,
  ) => {
    const { tool, sessionID } = input
    const toolLower = tool.toLowerCase()

    if (!isTargetAgent(sessionID, input.agent)) {
      return
    }

    const state = getOrCreateState(sessionID)

    if (DELEGATION_TOOLS.has(toolLower)) {
      state.delegationUsed = true
      log("[category-skill-reminder] Delegation tool used", { sessionID, tool })
      return
    }

    if (!DELEGATABLE_WORK_TOOLS.has(toolLower)) {
      return
    }

    state.toolCallCount++

    if (state.toolCallCount >= 3 && !state.delegationUsed && !state.reminderShown) {
      output.output += REMINDER_MESSAGE
      state.reminderShown = true
      log("[category-skill-reminder] Reminder injected", { 
        sessionID, 
        toolCallCount: state.toolCallCount 
      })
    }
  }

  const eventHandler = async ({ event }: { event: { type: string; properties?: unknown } }) => {
    const props = event.properties as Record<string, unknown> | undefined

    if (event.type === "session.deleted") {
      const sessionInfo = props?.info as { id?: string } | undefined
      if (sessionInfo?.id) {
        sessionStates.delete(sessionInfo.id)
      }
    }

    if (event.type === "session.compacted") {
      const sessionID = (props?.sessionID ??
        (props?.info as { id?: string } | undefined)?.id) as string | undefined
      if (sessionID) {
        sessionStates.delete(sessionID)
      }
    }
  }

  return {
    "tool.execute.after": toolExecuteAfter,
    event: eventHandler,
  }
}