import fs from "fs/promises"
import path from "path"
import { describe, expect } from "bun:test"
import { Effect, Exit, Layer } from "effect"
import { LayerNode } from "@opencode-ai/util/effect/layer-node"
import { FileSystem } from "@opencode-ai/core/filesystem"
import { Location } from "@opencode-ai/core/location"
import { AbsolutePath, RelativePath } from "@opencode-ai/core/schema"
import { Workspace } from "@opencode-ai/core/workspace"
import { location } from "./fixture/location"
import { tmpdir } from "./fixture/tmpdir"
import { it } from "./lib/effect"

const provide = (directory: string, workspaceID?: Workspace.ID) =>
  Effect.provide(
    LayerNode.compile(FileSystem.node, {
      replacements: [
        Location.node.replace(
          Layer.succeed(
            Location.Service,
            Location.Service.of(location({ directory: AbsolutePath.make(directory), workspaceID })),
          ),
        ),
      ],
    }),
  )

const withTmp = <A, E, R>(f: (directory: string) => Effect.Effect<A, E, R>) =>
  Effect.acquireRelease(
    Effect.promise(() => tmpdir()),
    (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
  ).pipe(Effect.flatMap((tmp) => f(tmp.path)))

describe("FileSystem", () => {
  it.live("reads text and binary files", () =>
    withTmp((directory) =>
      Effect.gen(function* () {
        yield* Effect.promise(() => fs.writeFile(path.join(directory, "text.txt"), "hello"))
        yield* Effect.promise(() => fs.writeFile(path.join(directory, "data.bin"), Buffer.from([0, 1, 2])))
        const service = yield* FileSystem.Service
        const text = yield* service.read({ path: RelativePath.make("text.txt") })
        const binary = yield* service.read({ path: RelativePath.make("data.bin") })
        expect(new TextDecoder().decode(text.content)).toBe("hello")
        expect(text.mime).toBe("text/plain")
        expect(binary.content).toEqual(new Uint8Array([0, 1, 2]))
      }).pipe(provide(directory)),
    ),
  )

  it.live("lists direct children", () =>
    withTmp((directory) =>
      Effect.gen(function* () {
        yield* Effect.promise(() => fs.mkdir(path.join(directory, "src")))
        yield* Effect.promise(() => fs.writeFile(path.join(directory, "README.md"), "# Test"))
        const filesystem = yield* FileSystem.Service
        const entries = yield* filesystem.list()
        expect(entries.map((entry) => ({ path: entry.path, type: entry.type }))).toEqual([
          { path: RelativePath.make("src" + path.sep), type: "directory" },
          { path: RelativePath.make("README.md"), type: "file" },
        ])
      }).pipe(provide(directory)),
    ),
  )

  it.live("skips host canonicalization for workspace locations at boot", () =>
    withTmp((directory) =>
      Effect.gen(function* () {
        // The directory exists only inside the workspace, so boot must not
        // require it to exist on the host. Operations still access the host
        // filesystem per call (#44568); only boot canonicalization is skipped.
        const missing = path.join(directory, "workspace-only")
        const workspace = yield* FileSystem.Service.pipe(
          provide(missing, Workspace.ID.make("wrk_filesystem")),
          Effect.exit,
        )
        expect(Exit.isSuccess(workspace)).toBe(true)

        // A local ref with the same missing directory keeps failing boot:
        // host realpath canonicalization stays load-bearing for local placements.
        const local = yield* FileSystem.Service.pipe(provide(missing), Effect.exit)
        expect(Exit.isFailure(local)).toBe(true)
      }),
    ),
  )

  it.live("canonicalizes local symlinked directories", () =>
    withTmp((directory) =>
      Effect.gen(function* () {
        const real = path.join(directory, "real")
        yield* Effect.promise(() => fs.mkdir(real))
        yield* Effect.promise(() => fs.writeFile(path.join(real, "file.txt"), "linked"))
        const link = path.join(directory, "link")
        yield* Effect.promise(() => fs.symlink(real, link))
        // Reads resolve through the symlink only because boot canonicalized
        // the location root to the real directory.
        const read = yield* FileSystem.Service.pipe(
          Effect.flatMap((service) => service.read({ path: RelativePath.make("file.txt") })),
          provide(link),
        )
        expect(new TextDecoder().decode(read.content)).toBe("linked")
      }),
    ),
  )

  it.live("rejects lexical escapes", () =>
    withTmp((directory) =>
      Effect.gen(function* () {
        const filesystem = yield* FileSystem.Service
        const result = yield* filesystem.read({ path: RelativePath.make("../outside.txt") }).pipe(Effect.exit)
        expect(Exit.isFailure(result)).toBe(true)
      }).pipe(provide(directory)),
    ),
  )
})