import type { PluginInput } from "@opencode-ai/plugin"
import { tool, type ToolDefinition } from "@opencode-ai/plugin/tool"
import {
  SESSION_LIST_DESCRIPTION,
  SESSION_READ_DESCRIPTION,
  SESSION_SEARCH_DESCRIPTION,
  SESSION_INFO_DESCRIPTION,
} from "./constants"
import { getAllSessions, getMainSessions, getSessionInfo, readSessionMessages, readSessionTodos, sessionExists } from "./storage"
import {
  filterSessionsByDate,
  formatSessionInfo,
  formatSessionList,
  formatSessionMessages,
  formatSearchResults,
  searchInSession,
} from "./utils"
import type { SessionListArgs, SessionReadArgs, SessionSearchArgs, SessionInfoArgs, SearchResult } from "./types"

const SEARCH_TIMEOUT_MS = 60_000
const MAX_SESSIONS_TO_SCAN = 50

function withTimeout<T>(promise: Promise<T>, ms: number, operation: string): Promise<T> {
  return Promise.race([
    promise,
    new Promise<T>((_, reject) => setTimeout(() => reject(new Error(`${operation} timed out after ${ms}ms`)), ms)),
  ])
}

export function createSessionManagerTools(ctx: PluginInput): Record<string, ToolDefinition> {
  const session_list: ToolDefinition = tool({
    description: SESSION_LIST_DESCRIPTION,
    args: {
      limit: tool.schema.number().optional().describe("Maximum number of sessions to return"),
      from_date: tool.schema.string().optional().describe("Filter sessions from this date (ISO 8601 format)"),
      to_date: tool.schema.string().optional().describe("Filter sessions until this date (ISO 8601 format)"),
      project_path: tool.schema.string().optional().describe("Filter sessions by project path (default: current working directory)"),
    },
    execute: async (args: SessionListArgs, _context) => {
      try {
        const directory = args.project_path ?? ctx.directory
        let sessions = await getMainSessions({ directory })
        let sessionIDs = sessions.map((s) => s.id)

        if (args.from_date || args.to_date) {
          sessionIDs = await filterSessionsByDate(sessionIDs, args.from_date, args.to_date)
        }

        if (args.limit && args.limit > 0) {
          sessionIDs = sessionIDs.slice(0, args.limit)
        }

        return await formatSessionList(sessionIDs)
      } catch (e) {
        return `Error: ${e instanceof Error ? e.message : String(e)}`
      }
    },
  })

  const session_read: ToolDefinition = tool({
    description: SESSION_READ_DESCRIPTION,
    args: {
      session_id: tool.schema.string().describe("Session ID to read"),
      include_todos: tool.schema.boolean().optional().describe("Include todo list if available (default: false)"),
      include_transcript: tool.schema.boolean().optional().describe("Include transcript log if available (default: false)"),
      limit: tool.schema.number().optional().describe("Maximum number of messages to return (default: all)"),
    },
    execute: async (args: SessionReadArgs, _context) => {
      try {
        if (!sessionExists(args.session_id)) {
          return `Session not found: ${args.session_id}`
        }

        let messages = await readSessionMessages(args.session_id)

        if (args.limit && args.limit > 0) {
          messages = messages.slice(0, args.limit)
        }

        const todos = args.include_todos ? await readSessionTodos(args.session_id) : undefined

        return formatSessionMessages(messages, args.include_todos, todos)
      } catch (e) {
        return `Error: ${e instanceof Error ? e.message : String(e)}`
      }
    },
  })

  const session_search: ToolDefinition = tool({
    description: SESSION_SEARCH_DESCRIPTION,
    args: {
      query: tool.schema.string().describe("Search query string"),
      session_id: tool.schema.string().optional().describe("Search within specific session only (default: all sessions)"),
      case_sensitive: tool.schema.boolean().optional().describe("Case-sensitive search (default: false)"),
      limit: tool.schema.number().optional().describe("Maximum number of results to return (default: 20)"),
    },
    execute: async (args: SessionSearchArgs, _context) => {
      try {
        const resultLimit = args.limit && args.limit > 0 ? args.limit : 20

        const searchOperation = async (): Promise<SearchResult[]> => {
          if (args.session_id) {
            return searchInSession(args.session_id, args.query, args.case_sensitive, resultLimit)
          }

          const allSessions = await getAllSessions()
          const sessionsToScan = allSessions.slice(0, MAX_SESSIONS_TO_SCAN)

          const allResults: SearchResult[] = []
          for (const sid of sessionsToScan) {
            if (allResults.length >= resultLimit) break

            const remaining = resultLimit - allResults.length
            const sessionResults = await searchInSession(sid, args.query, args.case_sensitive, remaining)
            allResults.push(...sessionResults)
          }

          return allResults.slice(0, resultLimit)
        }

        const results = await withTimeout(searchOperation(), SEARCH_TIMEOUT_MS, "Search")

        return formatSearchResults(results)
      } catch (e) {
        return `Error: ${e instanceof Error ? e.message : String(e)}`
      }
    },
  })

  const session_info: ToolDefinition = tool({
    description: SESSION_INFO_DESCRIPTION,
    args: {
      session_id: tool.schema.string().describe("Session ID to inspect"),
    },
    execute: async (args: SessionInfoArgs, _context) => {
      try {
        const info = await getSessionInfo(args.session_id)

        if (!info) {
          return `Session not found: ${args.session_id}`
        }

        return formatSessionInfo(info)
      } catch (e) {
        return `Error: ${e instanceof Error ? e.message : String(e)}`
      }
    },
  })

  return { session_list, session_read, session_search, session_info }
}