import { Flag } from "@opencode-ai/core/flag/flag"
import { Cause, Duration, Effect } from "effect"
import { TestLLMServer } from "../../lib/llm-server"
import type { Config } from "../../../src/config/config"
import { ModelID, ProviderID } from "../../../src/provider/schema"
import type { MessageV2 } from "../../../src/session/message-v2"
import { MessageID, PartID } from "../../../src/session/schema"
import { stable } from "./assertions"
import { call, callAuthProbe } from "./backend"
import { original } from "./environment"
import { runtime } from "./runtime"
import type {
  ActiveScenario,
  CallResult,
  Options,
  ProjectOptions,
  Result,
  Scenario,
  ScenarioContext,
  SeededContext,
} from "./types"

export function runScenario(options: Options) {
  return (scenario: Scenario) => {
    if (scenario.kind === "todo") return Effect.succeed({ status: "skip", scenario } as Result)
    return runActive(options, scenario).pipe(
      Effect.timeoutOrElse({
        duration: options.scenarioTimeout,
        orElse: () => Effect.die(new Error(`scenario timed out after ${Duration.format(options.scenarioTimeout)}`)),
      }),
      Effect.as({ status: "pass", scenario } as Result),
      Effect.catchCause((cause) => Effect.succeed({ status: "fail" as const, scenario, message: Cause.pretty(cause) })),
      Effect.scoped,
    )
  }
}

function runActive(options: Options, scenario: ActiveScenario) {
  if (options.mode === "auth") return runAuth(scenario)

  if (options.mode === "parity" && scenario.mutates && scenario.compare !== "none") {
    return Effect.gen(function* () {
      const effect = yield* runBackend(options, "effect", scenario)
      const legacy = yield* runBackend(options, "legacy", scenario)
      yield* trace(options, scenario, "compare start")
      yield* compare(scenario, effect, legacy)
      yield* trace(options, scenario, "compare done")
    })
  }

  return withContext(options, scenario, "shared", (ctx) =>
    Effect.gen(function* () {
      yield* trace(options, scenario, "effect request start")
      const effect = yield* call("effect", scenario, ctx)
      yield* trace(options, scenario, `effect response ${effect.status}`)
      yield* trace(options, scenario, "effect expect start")
      yield* scenario.expect(ctx, ctx.state, effect)
      yield* trace(options, scenario, "effect expect done")
      if (options.mode === "parity" && scenario.compare !== "none") {
        yield* trace(options, scenario, "legacy request start")
        const legacy = yield* call("legacy", scenario, ctx)
        yield* trace(options, scenario, `legacy response ${legacy.status}`)
        yield* trace(options, scenario, "legacy expect start")
        yield* scenario.expect(ctx, ctx.state, legacy)
        yield* trace(options, scenario, "legacy expect done")
        yield* trace(options, scenario, "compare start")
        yield* compare(scenario, effect, legacy)
        yield* trace(options, scenario, "compare done")
      }
    }),
  )
}

function runAuth(scenario: ActiveScenario) {
  return Effect.gen(function* () {
    const effect = yield* callAuthProbe("effect", scenario, "missing")
    const legacy = yield* callAuthProbe("legacy", scenario, "missing")
    if (scenario.auth === "protected") {
      if (effect.status !== 401) throw new Error(`effect auth expected 401, got ${effect.status}`)
      if (legacy.status !== 401) throw new Error(`legacy auth expected 401, got ${legacy.status}`)
      const effectAuthed = yield* callAuthProbe("effect", scenario, "valid")
      const legacyAuthed = yield* callAuthProbe("legacy", scenario, "valid")
      if (effectAuthed.status === 401) throw new Error("effect auth rejected valid credentials")
      if (legacyAuthed.status === 401) throw new Error("legacy auth rejected valid credentials")
      return
    }

    if (effect.status === 401) throw new Error("effect auth expected public access, got 401")
    if (legacy.status === 401) throw new Error("legacy auth expected public access, got 401")
    if (effect.timedOut) throw new Error("effect auth expected public access, probe timed out")
    if (legacy.timedOut) throw new Error("legacy auth expected public access, probe timed out")
  })
}

function runBackend(options: Options, backend: "effect" | "legacy", scenario: ActiveScenario) {
  return withContext(options, scenario, backend, (ctx) =>
    Effect.gen(function* () {
      yield* trace(options, scenario, `${backend} request start`)
      const result = yield* call(backend, scenario, ctx)
      yield* trace(options, scenario, `${backend} response ${result.status}`)
      yield* trace(options, scenario, `${backend} expect start`)
      yield* scenario.expect(ctx, ctx.state, result)
      yield* trace(options, scenario, `${backend} expect done`)
      return result
    }),
  )
}

function withContext<A, E>(
  options: Options,
  scenario: ActiveScenario,
  label: string,
  use: (ctx: SeededContext<unknown>) => Effect.Effect<A, E>,
) {
  return Effect.acquireRelease(
    Effect.gen(function* () {
      yield* trace(options, scenario, `${label} context acquire start`)
      const llm = scenario.project?.llm ? yield* TestLLMServer : undefined
      const project = scenario.project
      const dir = project
        ? yield* Effect.promise(async () => (await runtime()).tmpdir(projectOptions(project, llm?.url)))
        : undefined
      yield* trace(options, scenario, `${label} context acquire done`)
      return { dir, llm }
    }),
    (ctx) =>
      Effect.gen(function* () {
        yield* trace(options, scenario, `${label} tmpdir cleanup start`)
        yield* Effect.promise(async () => {
          await ctx.dir?.[Symbol.asyncDispose]()
        }).pipe(Effect.ignore)
        yield* trace(options, scenario, `${label} tmpdir cleanup done`)
      }),
  ).pipe(
    Effect.flatMap((context) =>
      Effect.gen(function* () {
        yield* trace(options, scenario, `${label} runtime start`)
        const modules = yield* Effect.promise(() => runtime())
        yield* trace(options, scenario, `${label} runtime done`)
        const path = context.dir?.path
        const instance = path
          ? yield* trace(options, scenario, `${label} instance load start`).pipe(
              Effect.andThen(
                modules.InstanceStore.Service.use((store) => store.load({ directory: path })).pipe(
                  Effect.provide(modules.AppLayer),
                  Effect.catchCause((cause) =>
                    Effect.sleep("100 millis").pipe(
                      Effect.andThen(
                        modules.InstanceStore.Service.use((store) => store.load({ directory: path })).pipe(
                          Effect.provide(modules.AppLayer),
                        ),
                      ),
                      Effect.catchCause(() => Effect.failCause(cause)),
                    ),
                  ),
                ),
              ),
              Effect.tap(() => trace(options, scenario, `${label} instance load done`)),
            )
          : undefined
        const run = <A, E, R>(effect: Effect.Effect<A, E, R>) =>
          effect.pipe(Effect.provideService(modules.InstanceRef, instance), Effect.provide(modules.AppLayer))
        const directory = () => {
          if (!context.dir?.path) throw new Error("scenario needs a project directory")
          return context.dir.path
        }
        const llm = () => {
          if (!context.llm) throw new Error("scenario needs fake LLM")
          return context.llm
        }
        const base: ScenarioContext = {
          directory: context.dir?.path,
          headers: (extra) => ({
            ...(context.dir?.path ? { "x-opencode-directory": context.dir.path } : {}),
            ...extra,
          }),
          file: (name, content) =>
            Effect.promise(() => {
              return Bun.write(`${directory()}/${name}`, content)
            }).pipe(Effect.asVoid),
          session: (input) =>
            run(modules.Session.Service.use((svc) => svc.create({ title: input?.title, parentID: input?.parentID }))),
          sessionGet: (sessionID) =>
            run(modules.Session.Service.use((svc) => svc.get(sessionID))).pipe(
              Effect.catchCause(() => Effect.succeed(undefined)),
            ),
          project: () =>
            Effect.sync(() => {
              if (!instance) throw new Error("scenario needs a project directory")
              return instance.project
            }),
          message: (sessionID, input) =>
            Effect.gen(function* () {
              const info: MessageV2.User = {
                id: MessageID.ascending(),
                sessionID,
                role: "user",
                time: { created: Date.now() },
                agent: "build",
                model: {
                  providerID: ProviderID.opencode,
                  modelID: ModelID.make("test"),
                },
              }
              const part: MessageV2.TextPart = {
                id: PartID.ascending(),
                sessionID,
                messageID: info.id,
                type: "text",
                text: input?.text ?? "hello",
              }
              yield* run(
                modules.Session.Service.use((svc) =>
                  Effect.gen(function* () {
                    yield* svc.updateMessage(info)
                    yield* svc.updatePart(part)
                  }),
                ),
              )
              return { info, part }
            }),
          messages: (sessionID) => run(modules.Session.Service.use((svc) => svc.messages({ sessionID }))),
          todos: (sessionID, todos) => run(modules.Todo.Service.use((svc) => svc.update({ sessionID, todos }))),
          worktree: (input) => run(modules.Worktree.Service.use((svc) => svc.create(input))),
          worktreeRemove: (directory) =>
            run(modules.Worktree.Service.use((svc) => svc.remove({ directory })).pipe(Effect.ignore)),
          llmText: (value) => Effect.suspend(() => llm().text(value)),
          llmWait: (count) => Effect.suspend(() => llm().wait(count)),
          tuiRequest: (request) => Effect.sync(() => modules.Tui.submitTuiRequest(request)),
        }
        yield* trace(options, scenario, `${label} seed start`)
        const state = yield* scenario.seed(base)
        yield* trace(options, scenario, `${label} seed done`)
        yield* trace(options, scenario, `${label} use start`)
        const result = yield* use({ ...base, state })
        yield* trace(options, scenario, `${label} use done`)
        return result
      }).pipe(Effect.ensuring(context.llm ? context.llm.reset : Effect.void)),
    ),
    Effect.ensuring(scenario.reset ? resetState : Effect.void),
  )
}

function trace(options: Options, scenario: ActiveScenario, phase: string) {
  return Effect.sync(() => {
    if (!options.trace) return
    console.log(`[trace] ${scenario.name}: ${phase}`)
  })
}

function projectOptions(
  project: ProjectOptions,
  llmUrl: string | undefined,
): { git?: boolean; config?: Partial<Config.Info> } {
  if (!project.llm || !llmUrl) return { git: project.git, config: project.config }
  const fake = fakeLlmConfig(llmUrl)
  return {
    git: project.git,
    config: {
      ...fake,
      ...project.config,
      provider: {
        ...fake.provider,
        ...project.config?.provider,
      },
    },
  }
}

function fakeLlmConfig(url: string): Partial<Config.Info> {
  return {
    model: "test/test-model",
    small_model: "test/test-model",
    provider: {
      test: {
        name: "Test",
        id: "test",
        env: [],
        npm: "@ai-sdk/openai-compatible",
        models: {
          "test-model": {
            id: "test-model",
            name: "Test Model",
            attachment: false,
            reasoning: false,
            temperature: false,
            tool_call: true,
            release_date: "2025-01-01",
            limit: { context: 100000, output: 10000 },
            cost: { input: 0, output: 0 },
            options: {},
          },
        },
        options: {
          apiKey: "test-key",
          baseURL: url,
        },
      },
    },
  }
}

function compare(scenario: ActiveScenario, effect: CallResult, legacy: CallResult) {
  return Effect.sync(() => {
    if (effect.status !== legacy.status)
      throw new Error(`legacy returned ${legacy.status}, effect returned ${effect.status}`)
    if (scenario.compare === "status") return
    if (stable(effect.body) !== stable(legacy.body))
      throw new Error(`JSON parity mismatch\nlegacy: ${stable(legacy.body)}\neffect: ${stable(effect.body)}`)
  })
}

const resetState = Effect.promise(async () => {
  const modules = await runtime()
  Flag.OPENCODE_EXPERIMENTAL_HTTPAPI = original.OPENCODE_EXPERIMENTAL_HTTPAPI
  Flag.OPENCODE_SERVER_PASSWORD = original.OPENCODE_SERVER_PASSWORD
  Flag.OPENCODE_SERVER_USERNAME = original.OPENCODE_SERVER_USERNAME
  await modules.disposeAllInstances()
  await modules.resetDatabase()
  await Bun.sleep(25)
})