import type { Config } from "@/config/config"

import { ConfigV1 } from "@opencode-ai/core/v1/config/config"

import { SessionV1 } from "@opencode-ai/core/v1/session"

import type { Provider } from "@/provider/provider"

import { ProviderTransform } from "@/provider/transform"

import type { MessageV2 } from "./message-v2"

const COMPACTION_BUFFER = 20_000

export function usable(input: { cfg: ConfigV1.Info; model: Provider.Model; outputTokenMax?: number }) {

const context = input.model.limit.context

if (context === 0) return 0

const reserved =

input.cfg.compaction?.reserved ??

Math.min(COMPACTION_BUFFER, ProviderTransform.maxOutputTokens(input.model, input.outputTokenMax))

return input.model.limit.input

? Math.max(0, input.model.limit.input - reserved)

: Math.max(0, context - ProviderTransform.maxOutputTokens(input.model, input.outputTokenMax))

}

export function isOverflow(input: {

cfg: ConfigV1.Info

tokens: SessionV1.Assistant["tokens"]

model: Provider.Model

outputTokenMax?: number

}) {

if (input.cfg.compaction?.auto === false) return false

if (input.model.limit.context === 0) return false

const count =

input.tokens.total || input.tokens.input + input.tokens.output + input.tokens.cache.read + input.tokens.cache.write

return count >= usable(input)

}