import { execFileSync } from "node:child_process"
import { promises as fs } from "node:fs"
import { afterEach, beforeEach, describe, expect, it, spyOn } from "bun:test"
import { mkdirSync, rmSync, writeFileSync } from "node:fs"
import { tmpdir } from "node:os"
import { join } from "node:path"
import * as loader from "./loader"

const TEST_DIR = join(tmpdir(), `claude-code-command-loader-${Date.now()}`)

function writeCommand(directory: string, name: string, description: string): void {
  mkdirSync(directory, { recursive: true })
  writeFileSync(
    join(directory, `${name}.md`),
    `---\ndescription: ${description}\n---\nRun ${name}.\n`,
  )
}

describe("claude-code command loader", () => {
  let originalClaudeConfigDir: string | undefined
  let originalOpencodeConfigDir: string | undefined

  beforeEach(() => {
    mkdirSync(TEST_DIR, { recursive: true })
    originalClaudeConfigDir = process.env.CLAUDE_CONFIG_DIR
    originalOpencodeConfigDir = process.env.OPENCODE_CONFIG_DIR

    const claudeConfigDir = join(TEST_DIR, "claude-config")
    const opencodeConfigDir = join(TEST_DIR, "opencode-config")
    process.env.CLAUDE_CONFIG_DIR = claudeConfigDir
    process.env.OPENCODE_CONFIG_DIR = opencodeConfigDir

    if ("clearCommandLoaderCache" in loader && typeof loader.clearCommandLoaderCache === "function") {
      loader.clearCommandLoaderCache()
    }
  })

  afterEach(() => {
    if (originalClaudeConfigDir === undefined) {
      delete process.env.CLAUDE_CONFIG_DIR
    } else {
      process.env.CLAUDE_CONFIG_DIR = originalClaudeConfigDir
    }

    if (originalOpencodeConfigDir === undefined) {
      delete process.env.OPENCODE_CONFIG_DIR
    } else {
      process.env.OPENCODE_CONFIG_DIR = originalOpencodeConfigDir
    }

    if ("clearCommandLoaderCache" in loader && typeof loader.clearCommandLoaderCache === "function") {
      loader.clearCommandLoaderCache()
    }

    rmSync(TEST_DIR, { recursive: true, force: true })
  })

  it("#given a parent .opencode/commands directory #when loadOpencodeProjectCommands is called from child directory #then it loads the ancestor command", async () => {
    // given
    const projectDir = join(TEST_DIR, "project")
    const childDir = join(projectDir, "apps", "desktop")
    writeCommand(join(projectDir, ".opencode", "commands"), "ancestor", "Ancestor command")

    // when
    const commands = await loader.loadOpencodeProjectCommands(childDir)

    // then
    expect(commands.ancestor?.description).toBe("(opencode-project) Ancestor command")
  })

  it("#given a .opencode/command directory #when loadOpencodeProjectCommands is called #then it loads the singular alias directory", async () => {
    // given
    writeCommand(join(TEST_DIR, ".opencode", "command"), "singular", "Singular command")

    // when
    const commands = await loader.loadOpencodeProjectCommands(TEST_DIR)

    // then
    expect(commands.singular?.description).toBe("(opencode-project) Singular command")
  })

  it("#given duplicate project command names across ancestors #when loadOpencodeProjectCommands is called #then the nearest directory wins", async () => {
    // given
    const projectRoot = join(TEST_DIR, "project")
    const childDir = join(projectRoot, "apps", "desktop")
    const ancestorDir = join(TEST_DIR, ".opencode", "commands")
    const projectDir = join(projectRoot, ".opencode", "commands")
    writeCommand(ancestorDir, "duplicate", "Ancestor command")
    writeCommand(projectDir, "duplicate", "Nearest command")

    // when
    const commands = await loader.loadOpencodeProjectCommands(childDir)

    // then
    expect(commands.duplicate?.description).toBe("(opencode-project) Nearest command")
  })

  it("#given a global .opencode/commands directory #when loadOpencodeGlobalCommands is called #then it loads the plural alias directory", async () => {
    // given
    const opencodeConfigDir = join(TEST_DIR, "opencode-config")
    process.env.OPENCODE_CONFIG_DIR = opencodeConfigDir
    writeCommand(join(opencodeConfigDir, "commands"), "global-plural", "Global plural command")

    // when
    const commands = await loader.loadOpencodeGlobalCommands()

    // then
    expect(commands["global-plural"]?.description).toBe("(opencode) Global plural command")
  })

  it("#given duplicate global command names across profile and parent dirs #when loadOpencodeGlobalCommands is called #then the profile dir wins", async () => {
    // given
    const opencodeRootDir = join(TEST_DIR, "opencode-root")
    const profileConfigDir = join(opencodeRootDir, "profiles", "codex")
    process.env.OPENCODE_CONFIG_DIR = profileConfigDir
    writeCommand(join(opencodeRootDir, "commands"), "duplicate-global", "Parent global command")
    writeCommand(join(profileConfigDir, "commands"), "duplicate-global", "Profile global command")

    // when
    const commands = await loader.loadOpencodeGlobalCommands()

    // then
    expect(commands["duplicate-global"]?.description).toBe("(opencode) Profile global command")
  })

  it("#given nested project opencode commands in a worktree #when loadOpencodeProjectCommands is called #then it preserves slash names and stops at the worktree root", async () => {
    // given
    const repositoryDir = join(TEST_DIR, "repo")
    const nestedDirectory = join(repositoryDir, "packages", "app", "src")
    mkdirSync(nestedDirectory, { recursive: true })
    execFileSync("git", ["init"], {
      cwd: repositoryDir,
      stdio: ["ignore", "ignore", "ignore"],
    })
    writeCommand(join(repositoryDir, ".opencode", "commands", "deploy"), "staging", "Deploy staging")
    writeCommand(join(repositoryDir, ".opencode", "command"), "release", "Release command")
    writeCommand(join(TEST_DIR, ".opencode", "commands"), "outside", "Outside command")

    // when
    const commands = await loader.loadOpencodeProjectCommands(nestedDirectory)

    // then
    expect(commands["deploy/staging"]?.description).toBe("(opencode-project) Deploy staging")
    expect(commands.release?.description).toBe("(opencode-project) Release command")
    expect(commands.outside).toBeUndefined()
    expect(commands["deploy:staging"]).toBeUndefined()
  })

  it("#given commands nested under an excluded basename #when loadProjectCommands is called #then it skips the excluded directory contents", async () => {
    // given
    writeCommand(join(TEST_DIR, ".claude", "commands"), "real", "Real command")
    writeCommand(
      join(TEST_DIR, ".claude", "commands", "node_modules"),
      "fake",
      "Fake command",
    )

    // when
    const commands = await loader.loadProjectCommands(TEST_DIR)

    // then
    expect(commands.real?.description).toBe("(project) Real command")
    expect(commands.fake).toBeUndefined()
  })

  it("#given a previously loaded directory #when loadAllCommands is called twice #then the second call reuses the cached result without readdir calls", async () => {
    // given
    writeCommand(join(TEST_DIR, ".claude", "commands"), "cached", "Cached command")
    const readdirSpy = spyOn(fs, "readdir")

    // when
    const firstCommands = await loader.loadAllCommands(TEST_DIR)
    const firstReaddirCount = readdirSpy.mock.calls.length
    const secondCommands = await loader.loadAllCommands(TEST_DIR)

    // then
    expect(firstCommands.cached?.description).toBe("(project) Cached command")
    expect(secondCommands).toEqual(firstCommands)
    expect(firstReaddirCount).toBeGreaterThan(0)
    expect(readdirSpy.mock.calls.length).toBe(firstReaddirCount)
  })
})