import { describe, it, expect, beforeEach, afterEach } from "bun:test"
import { join } from "node:path"
import { homedir } from "node:os"
import { promises as fs } from "node:fs"
import { tmpdir } from "node:os"
import type { AccountStorage } from "./types"
import { getDataDir, getStoragePath, loadAccounts, saveAccounts } from "./storage"

describe("storage", () => {
  const testDir = join(tmpdir(), `oh-my-opencode-storage-test-${Date.now()}`)
  const testStoragePath = join(testDir, "oh-my-opencode-accounts.json")

  const validStorage: AccountStorage = {
    version: 1,
    accounts: [
      {
        email: "test@example.com",
        tier: "free",
        refreshToken: "refresh-token-123",
        projectId: "project-123",
        accessToken: "access-token-123",
        expiresAt: Date.now() + 3600000,
        rateLimits: {},
      },
    ],
    activeIndex: 0,
  }

  beforeEach(async () => {
    await fs.mkdir(testDir, { recursive: true })
  })

  afterEach(async () => {
    try {
      await fs.rm(testDir, { recursive: true, force: true })
    } catch {
      // ignore cleanup errors
    }
  })

  describe("getDataDir", () => {
    it("returns path containing opencode directory", () => {
      // #given
      // platform is current system

      // #when
      const result = getDataDir()

      // #then
      expect(result).toContain("opencode")
    })

    it("returns XDG_DATA_HOME/opencode when XDG_DATA_HOME is set on non-Windows", () => {
      // #given
      const originalXdg = process.env.XDG_DATA_HOME
      const originalPlatform = process.platform

      if (originalPlatform === "win32") {
        return
      }

      try {
        process.env.XDG_DATA_HOME = "/custom/data"

        // #when
        const result = getDataDir()

        // #then
        expect(result).toBe("/custom/data/opencode")
      } finally {
        if (originalXdg !== undefined) {
          process.env.XDG_DATA_HOME = originalXdg
        } else {
          delete process.env.XDG_DATA_HOME
        }
      }
    })

    it("returns ~/.local/share/opencode when XDG_DATA_HOME is not set on non-Windows", () => {
      // #given
      const originalXdg = process.env.XDG_DATA_HOME
      const originalPlatform = process.platform

      if (originalPlatform === "win32") {
        return
      }

      try {
        delete process.env.XDG_DATA_HOME

        // #when
        const result = getDataDir()

        // #then
        expect(result).toBe(join(homedir(), ".local", "share", "opencode"))
      } finally {
        if (originalXdg !== undefined) {
          process.env.XDG_DATA_HOME = originalXdg
        } else {
          delete process.env.XDG_DATA_HOME
        }
      }
    })
  })

  describe("getStoragePath", () => {
    it("returns path ending with oh-my-opencode-accounts.json", () => {
      // #given
      // no setup needed

      // #when
      const result = getStoragePath()

      // #then
      expect(result.endsWith("oh-my-opencode-accounts.json")).toBe(true)
      expect(result).toContain("opencode")
    })
  })

  describe("loadAccounts", () => {
    it("returns parsed storage when file exists and is valid", async () => {
      // #given
      await fs.writeFile(testStoragePath, JSON.stringify(validStorage), "utf-8")

      // #when
      const result = await loadAccounts(testStoragePath)

      // #then
      expect(result).not.toBeNull()
      expect(result?.version).toBe(1)
      expect(result?.accounts).toHaveLength(1)
      expect(result?.accounts[0].email).toBe("test@example.com")
    })

    it("returns null when file does not exist (ENOENT)", async () => {
      // #given
      const nonExistentPath = join(testDir, "non-existent.json")

      // #when
      const result = await loadAccounts(nonExistentPath)

      // #then
      expect(result).toBeNull()
    })

    it("returns null when file contains invalid JSON", async () => {
      // #given
      const invalidJsonPath = join(testDir, "invalid.json")
      await fs.writeFile(invalidJsonPath, "{ invalid json }", "utf-8")

      // #when
      const result = await loadAccounts(invalidJsonPath)

      // #then
      expect(result).toBeNull()
    })

    it("returns null when file contains valid JSON but invalid schema", async () => {
      // #given
      const invalidSchemaPath = join(testDir, "invalid-schema.json")
      await fs.writeFile(invalidSchemaPath, JSON.stringify({ foo: "bar" }), "utf-8")

      // #when
      const result = await loadAccounts(invalidSchemaPath)

      // #then
      expect(result).toBeNull()
    })

    it("returns null when accounts is not an array", async () => {
      // #given
      const invalidAccountsPath = join(testDir, "invalid-accounts.json")
      await fs.writeFile(
        invalidAccountsPath,
        JSON.stringify({ version: 1, accounts: "not-array", activeIndex: 0 }),
        "utf-8"
      )

      // #when
      const result = await loadAccounts(invalidAccountsPath)

      // #then
      expect(result).toBeNull()
    })

    it("returns null when activeIndex is not a number", async () => {
      // #given
      const invalidIndexPath = join(testDir, "invalid-index.json")
      await fs.writeFile(
        invalidIndexPath,
        JSON.stringify({ version: 1, accounts: [], activeIndex: "zero" }),
        "utf-8"
      )

      // #when
      const result = await loadAccounts(invalidIndexPath)

      // #then
      expect(result).toBeNull()
    })
  })

  describe("saveAccounts", () => {
    it("writes storage to file with proper JSON formatting", async () => {
      // #given
      // testStoragePath is ready

      // #when
      await saveAccounts(validStorage, testStoragePath)

      // #then
      const content = await fs.readFile(testStoragePath, "utf-8")
      const parsed = JSON.parse(content)
      expect(parsed.version).toBe(1)
      expect(parsed.accounts).toHaveLength(1)
      expect(parsed.activeIndex).toBe(0)
    })

    it("creates parent directories if they do not exist", async () => {
      // #given
      const nestedPath = join(testDir, "nested", "deep", "oh-my-opencode-accounts.json")

      // #when
      await saveAccounts(validStorage, nestedPath)

      // #then
      const content = await fs.readFile(nestedPath, "utf-8")
      const parsed = JSON.parse(content)
      expect(parsed.version).toBe(1)
    })

    it("overwrites existing file", async () => {
      // #given
      const existingStorage: AccountStorage = {
        version: 1,
        accounts: [],
        activeIndex: 0,
      }
      await fs.writeFile(testStoragePath, JSON.stringify(existingStorage), "utf-8")

      // #when
      await saveAccounts(validStorage, testStoragePath)

      // #then
      const content = await fs.readFile(testStoragePath, "utf-8")
      const parsed = JSON.parse(content)
      expect(parsed.accounts).toHaveLength(1)
    })

    it("uses pretty-printed JSON with 2-space indentation", async () => {
      // #given
      // testStoragePath is ready

      // #when
      await saveAccounts(validStorage, testStoragePath)

      // #then
      const content = await fs.readFile(testStoragePath, "utf-8")
      expect(content).toContain("\n")
      expect(content).toContain("  ")
    })

    it("sets restrictive file permissions (0o600) for security", async () => {
      // #given
      // testStoragePath is ready

      // #when
      await saveAccounts(validStorage, testStoragePath)

      // #then
      const stats = await fs.stat(testStoragePath)
      const mode = stats.mode & 0o777
      expect(mode).toBe(0o600)
    })

    it("uses atomic write pattern with temp file and rename", async () => {
      // #given
      // This test verifies that the file is written atomically
      // by checking that no partial writes occur

      // #when
      await saveAccounts(validStorage, testStoragePath)

      // #then
      // If we can read valid JSON, the atomic write succeeded
      const content = await fs.readFile(testStoragePath, "utf-8")
      const parsed = JSON.parse(content)
      expect(parsed.version).toBe(1)
      expect(parsed.accounts).toHaveLength(1)
    })

    it("cleans up temp file on rename failure", async () => {
      // #given
      const readOnlyDir = join(testDir, "readonly")
      await fs.mkdir(readOnlyDir, { recursive: true })
      const readOnlyPath = join(readOnlyDir, "accounts.json")

      await fs.writeFile(readOnlyPath, "{}", "utf-8")
      await fs.chmod(readOnlyPath, 0o444)

      // #when
      let didThrow = false
      try {
        await saveAccounts(validStorage, readOnlyPath)
      } catch {
        didThrow = true
      }

      // #then
      const files = await fs.readdir(readOnlyDir)
      const tempFiles = files.filter((f) => f.includes(".tmp."))
      expect(tempFiles).toHaveLength(0)

      if (!didThrow) {
        console.log("[TEST SKIP] File permissions did not work as expected on this system")
      }

      // Cleanup
      await fs.chmod(readOnlyPath, 0o644)
    })

    it("uses unique temp filename with pid and timestamp", async () => {
      // #given
      // We verify this by checking the implementation behavior
      // The temp file should include process.pid and Date.now()

      // #when
      await saveAccounts(validStorage, testStoragePath)

      // #then
      // File should exist and be valid (temp file was successfully renamed)
      const exists = await fs.access(testStoragePath).then(() => true).catch(() => false)
      expect(exists).toBe(true)
    })

    it("handles sequential writes without corruption", async () => {
      // #given
      const storage1: AccountStorage = {
        ...validStorage,
        accounts: [{ ...validStorage.accounts[0]!, email: "user1@example.com" }],
      }
      const storage2: AccountStorage = {
        ...validStorage,
        accounts: [{ ...validStorage.accounts[0]!, email: "user2@example.com" }],
      }

      // #when - sequential writes (concurrent writes are inherently racy)
      await saveAccounts(storage1, testStoragePath)
      await saveAccounts(storage2, testStoragePath)

      // #then - file should contain valid JSON from last write
      const content = await fs.readFile(testStoragePath, "utf-8")
      const parsed = JSON.parse(content) as AccountStorage
      expect(parsed.version).toBe(1)
      expect(parsed.accounts[0]?.email).toBe("user2@example.com")
    })
  })

  describe("loadAccounts error handling", () => {
    it("re-throws non-ENOENT filesystem errors", async () => {
      // #given
      const unreadableDir = join(testDir, "unreadable")
      await fs.mkdir(unreadableDir, { recursive: true })
      const unreadablePath = join(unreadableDir, "accounts.json")
      await fs.writeFile(unreadablePath, JSON.stringify(validStorage), "utf-8")
      await fs.chmod(unreadablePath, 0o000)

      // #when
      let thrownError: Error | null = null
      let result: unknown = undefined
      try {
        result = await loadAccounts(unreadablePath)
      } catch (error) {
        thrownError = error as Error
      }

      // #then
      if (thrownError) {
        expect((thrownError as NodeJS.ErrnoException).code).not.toBe("ENOENT")
      } else {
        console.log("[TEST SKIP] File permissions did not work as expected on this system, got result:", result)
      }

      // Cleanup
      await fs.chmod(unreadablePath, 0o644)
    })
  })
})