import { describe } from "bun:test";
import { createTestBuilder } from "./test_builder";
const TestBuilder = createTestBuilder(import.meta.path);

describe("IOWriter file output redirection", () => {
  describe("basic file redirection", () => {
    TestBuilder.command`echo "hello world" > output.txt`
      .exitCode(0)
      .fileEquals("output.txt", "hello world\n")
      .runAsTest("simple echo to file");

    TestBuilder.command`echo -n "" > empty.txt`
      .exitCode(0)
      .fileEquals("empty.txt", "")
      .runAsTest("empty output to file");

    TestBuilder.command`echo "" > zero.txt`
      .exitCode(0)
      .fileEquals("zero.txt", "\n")
      .runAsTest("zero-length write should trigger onIOWriterChunk callback");
  });

  describe("drainBufferedData edge cases", () => {
    TestBuilder.command`echo -n ${"x".repeat(1024 * 10)} > large.txt`
      .exitCode(0)
      .fileEquals("large.txt", "x".repeat(1024 * 10))
      .runAsTest("large single write");

    TestBuilder.command`mkdir -p subdir && echo "test" > subdir/file.txt`
      .exitCode(0)
      .fileEquals("subdir/file.txt", "test\n")
      .runAsTest("write to subdirectory");
  });

  describe("file system error conditions", () => {
    TestBuilder.command`echo "should fail" > /dev/null/invalid/path`
      .exitCode(1)
      .stderr_contains("directory: /dev/null/invalid/path")
      .runAsTest("write to invalid path should fail");

    TestBuilder.command`echo "should fail" > /nonexistent/file.txt`
      .exitCode(1)
      .stderr_contains("No such file or directory")
      .runAsTest("write to non-existent directory should fail");
  });

  describe("special file types", () => {
    TestBuilder.command`echo "disappear" > /dev/null`.exitCode(0).stdout("").runAsTest("write to /dev/null");
  });

  describe("writer queue and bump behavior", () => {
    TestBuilder.command`echo "single" > single_writer.txt`
      .exitCode(0)
      .fileEquals("single_writer.txt", "single\n")
      .runAsTest("single writer completion and cleanup");

    TestBuilder.command`echo "robust test" > robust.txt`
      .exitCode(0)
      .fileEquals("robust.txt", "robust test\n")
      .runAsTest("writer marked as dead during write");

    TestBuilder.command`echo "captured content" > capture.txt`
      .exitCode(0)
      .fileEquals("capture.txt", "captured content\n")
      .stdout("")
      .runAsTest("bytelist capture during file write");
  });

  describe("error handling and unreachable paths", () => {
    TestBuilder.command`echo -n ${"A".repeat(2 * 1024)} > atomic.txt`
      .exitCode(0)
      .fileEquals("atomic.txt", "A".repeat(2 * 1024))
      .runAsTest("attempt to trigger partial write panic");

    TestBuilder.command`echo "synchronous" > sync_write.txt`
      .exitCode(0)
      .fileEquals("sync_write.txt", "synchronous\n")
      .runAsTest("EAGAIN should never occur for files");

    TestBuilder.command`echo "error test" > nonexistent_dir/file.txt`
      .exitCode(1)
      .stderr_contains("No such file or directory")
      .runAsTest("write error propagation");
  });

  describe("file permissions and creation", () => {
    TestBuilder.command`echo "new file" > new_file.txt`
      .exitCode(0)
      .fileEquals("new_file.txt", "new file\n")
      .runAsTest("file creation with default permissions");

    TestBuilder.command`echo "original" > overwrite.txt && echo "short" > overwrite.txt`
      .exitCode(0)
      .fileEquals("overwrite.txt", "short\n")
      .runAsTest("overwrite existing file");

    TestBuilder.command`echo "line1" > append.txt && echo "line2" >> append.txt && echo "line3" >> append.txt`
      .exitCode(0)
      .fileEquals("append.txt", "line1\nline2\nline3\n")
      .runAsTest("append to existing file");
  });

  // describe("concurrent operations", () => {
  //   TestBuilder.command`echo "content 0" > concurrent_0.txt & echo "content 1" > concurrent_1.txt & echo "content 2" > concurrent_2.txt & wait`
  //     .exitCode(0)
  //     .fileEquals("concurrent_0.txt", "content 0\n")
  //     .fileEquals("concurrent_1.txt", "content 1\n")
  //     .fileEquals("concurrent_2.txt", "content 2\n")
  //     .runAsTest("concurrent writes to different files");

  //   TestBuilder.command`echo "iteration 0" > rapid.txt && echo "iteration 1" > rapid.txt && echo "iteration 2" > rapid.txt`
  //     .exitCode(0)
  //     .fileEquals("rapid.txt", "iteration 2\n")
  //     .runAsTest("rapid sequential writes to same file");
  // });

  describe("additional TestBuilder integration", () => {
    TestBuilder.command`echo "builder test" > output.txt`
      .exitCode(0)
      .fileEquals("output.txt", "builder test\n")
      .runAsTest("basic file output");

    TestBuilder.command`printf "no newline" > no_newline.txt`
      .exitCode(0)
      .fileEquals("no_newline.txt", "no newline")
      .runAsTest("output without trailing newline");

    TestBuilder.command`echo "first" > multi.txt && echo "second" >> multi.txt`
      .exitCode(0)
      .fileEquals("multi.txt", "first\nsecond\n")
      .runAsTest("write then append");

    TestBuilder.command`echo "test with spaces in filename" > "file with spaces.txt"`
      .exitCode(0)
      .fileEquals("file with spaces.txt", "test with spaces in filename\n")
      .runAsTest("write to file with spaces in name");

    TestBuilder.command`echo "pipe test" | cat > pipe_output.txt`
      .exitCode(0)
      .fileEquals("pipe_output.txt", "pipe test\n")
      .runAsTest("pipe with file redirection");
  });

  describe("&> redirect (stdout and stderr to same file)", () => {
    // This test verifies the fix for the bug where using &> with a builtin
    // command caused the same file descriptor to be closed twice, resulting
    // in an EBADF error. The issue was that two separate IOWriter instances
    // were created for the same fd when both stdout and stderr were redirected.
    TestBuilder.command`pwd &> pwd_output.txt`.exitCode(0).runAsTest("builtin pwd with &> redirect");

    TestBuilder.command`echo "hello" &> echo_output.txt`
      .exitCode(0)
      .fileEquals("echo_output.txt", "hello\n")
      .runAsTest("builtin echo with &> redirect");

    TestBuilder.command`pwd &>> append_output.txt`.exitCode(0).runAsTest("builtin pwd with &>> append redirect");
  });
});