import { z } from "zod"
import { Effect } from "effect"

export type ToolContext = {
 sessionID: string
 messageID: string
 agent: string
 /**
 * Current project directory for this session.
 * Prefer this over process.cwd() when resolving relative paths.
 */
 directory: string
 /**
 * Project worktree root for this session.
 * Useful for generating stable relative paths (e.g. path.relative(worktree, absPath)).
 */
 worktree: string
 abort: AbortSignal
 metadata(input: { title?: string; metadata?: { [key: string]: any } }): void
 ask(input: AskInput): Effect.Effect<void>
}

type AskInput = {
 permission: string
 patterns: string[]
 always: string[]
 metadata: { [key: string]: any }
}

export type ToolAttachment = {
 type: "file"
 mime: string
 url: string
 filename?: string
}

export type ToolResult =
 | string
 | {
 title?: string
 output: string
 metadata?: { [key: string]: any }
 attachments?: ToolAttachment[]
 }

export function tool<Args extends z.ZodRawShape>(input: {
 description: string
 args: Args
 execute(args: z.infer<z.ZodObject<Args>>, context: ToolContext): Promise<ToolResult>
}) {
 return input
}
tool.schema = z

export type ToolDefinition = ReturnType<typeof tool>