import { describe, test, expect } from "bun:test"

import { createChatMessageHandler } from "./chat-message"

type ChatMessagePart = { type: string; text?: string; [key: string]: unknown }
type ChatMessageHandlerOutput = { message: Record<string, unknown>; parts: ChatMessagePart[] }

function createMockHandlerArgs(overrides?: {
  pluginConfig?: Record<string, unknown>
  shouldOverride?: boolean
}) {
  const appliedSessions: string[] = []
  return {
    ctx: { client: { tui: { showToast: async () => {} } } } as any,
    pluginConfig: (overrides?.pluginConfig ?? {}) as any,
    firstMessageVariantGate: {
      shouldOverride: () => overrides?.shouldOverride ?? false,
      markApplied: (sessionID: string) => { appliedSessions.push(sessionID) },
    },
    hooks: {
      stopContinuationGuard: null,
      keywordDetector: null,
      claudeCodeHooks: null,
      autoSlashCommand: null,
      startWork: null,
      ralphLoop: null,
    } as any,
    _appliedSessions: appliedSessions,
  }
}

function createMockInput(agent?: string, model?: { providerID: string; modelID: string }) {
  return {
    sessionID: "test-session",
    agent,
    model,
  }
}

function createMockOutput(variant?: string): ChatMessageHandlerOutput {
  const message: Record<string, unknown> = {}
  if (variant !== undefined) {
    message["variant"] = variant
  }
  return { message, parts: [] }
}

describe("createChatMessageHandler - first message variant", () => {
  test("first message: sets variant from fallback chain when user has no selection", async () => {
    //#given - first message, no user-selected variant, hephaestus with medium in chain
    const args = createMockHandlerArgs({ shouldOverride: true })
    const handler = createChatMessageHandler(args)
    const input = createMockInput("hephaestus", { providerID: "openai", modelID: "gpt-5.3-codex" })
    const output = createMockOutput() // no variant set

    //#when
    await handler(input, output)

    //#then - should set variant from fallback chain
    expect(output.message["variant"]).toBeDefined()
  })

  test("first message: preserves user-selected variant when already set", async () => {
    //#given - first message, user already selected "xhigh" variant in OpenCode UI
    const args = createMockHandlerArgs({ shouldOverride: true })
    const handler = createChatMessageHandler(args)
    const input = createMockInput("hephaestus", { providerID: "openai", modelID: "gpt-5.3-codex" })
    const output = createMockOutput("xhigh") // user selected xhigh

    //#when
    await handler(input, output)

    //#then - user's xhigh must be preserved, not overwritten to "medium"
    expect(output.message["variant"]).toBe("xhigh")
  })

  test("first message: preserves user-selected 'high' variant", async () => {
    //#given - user selected "high" variant
    const args = createMockHandlerArgs({ shouldOverride: true })
    const handler = createChatMessageHandler(args)
    const input = createMockInput("hephaestus", { providerID: "openai", modelID: "gpt-5.3-codex" })
    const output = createMockOutput("high")

    //#when
    await handler(input, output)

    //#then
    expect(output.message["variant"]).toBe("high")
  })

  test("subsequent message: does not override existing variant", async () => {
    //#given - not first message, variant already set
    const args = createMockHandlerArgs({ shouldOverride: false })
    const handler = createChatMessageHandler(args)
    const input = createMockInput("hephaestus", { providerID: "openai", modelID: "gpt-5.3-codex" })
    const output = createMockOutput("xhigh")

    //#when
    await handler(input, output)

    //#then
    expect(output.message["variant"]).toBe("xhigh")
  })

  test("first message: marks gate as applied regardless of variant presence", async () => {
    //#given - first message with user-selected variant
    const args = createMockHandlerArgs({ shouldOverride: true })
    const handler = createChatMessageHandler(args)
    const input = createMockInput("hephaestus", { providerID: "openai", modelID: "gpt-5.3-codex" })
    const output = createMockOutput("xhigh")

    //#when
    await handler(input, output)

    //#then - gate should still be marked as applied
    expect(args._appliedSessions).toContain("test-session")
  })
})