// ==========================================================================
// Script Execution Tests
// ==========================================================================
//
// These tests extract a real Anvil project to a temp directory and then
// ACTUALLY EXECUTE the generated scripts.  They are not fast and they
// require real build-machine dependencies:
//
//   test/run_tests.sh  -->  cmake, g++ (or clang++), git
//   build.sh           -->  arduino-cli  (with arduino:avr core installed)
//
// If any dependency is missing the test FAILS -- that is intentional.
// A build machine that ships Anvil binaries MUST have these tools.
//
// On Windows the .bat variants are tested instead.
// ==========================================================================

use std::fs;
use std::path::Path;
use std::process::Command;
use tempfile::TempDir;

use anvil::templates::{TemplateContext, TemplateManager};
use anvil::version::ANVIL_VERSION;

// --------------------------------------------------------------------------
// Helpers
// --------------------------------------------------------------------------

/// Extract a fresh project into a temp directory and return the TempDir.
fn extract_project(name: &str) -> TempDir {
    let tmp = TempDir::new().expect("Failed to create temp directory");
    let ctx = TemplateContext {
        project_name: name.to_string(),
        anvil_version: ANVIL_VERSION.to_string(),
    };
    let count = TemplateManager::extract("basic", tmp.path(), &ctx)
        .expect("Failed to extract template");
    assert!(count > 0, "Template extraction produced zero files");
    tmp
}

/// Make all .sh files under `root` executable (Unix only).
#[cfg(unix)]
fn chmod_scripts(root: &Path) {
    use std::os::unix::fs::PermissionsExt;

    for entry in walkdir::WalkDir::new(root)
        .into_iter()
        .filter_map(|e| e.ok())
    {
        let p = entry.path();
        if p.extension().map(|e| e == "sh").unwrap_or(false) {
            let mut perms = fs::metadata(p)
                .expect("Failed to read metadata")
                .permissions();
            perms.set_mode(0o755);
            fs::set_permissions(p, perms).expect("Failed to chmod");
        }
    }
}

/// Run a shell script (bash on Unix, cmd /C on Windows).
/// Returns (success, stdout, stderr).
fn run_script(dir: &Path, script: &str) -> (bool, String, String) {
    let output = if cfg!(windows) {
        Command::new("cmd")
            .args(["/C", script])
            .current_dir(dir)
            .output()
    } else {
        Command::new("bash")
            .arg(script)
            .current_dir(dir)
            .output()
    };

    let output = output.unwrap_or_else(|e| panic!("Failed to execute {}: {}", script, e));
    let stdout = String::from_utf8_lossy(&output.stdout).to_string();
    let stderr = String::from_utf8_lossy(&output.stderr).to_string();
    (output.status.success(), stdout, stderr)
}

/// Run a script with extra arguments.
fn run_script_with_args(dir: &Path, script: &str, args: &[&str]) -> (bool, String, String) {
    let output = if cfg!(windows) {
        let mut all_args = vec!["/C", script];
        all_args.extend_from_slice(args);
        Command::new("cmd")
            .args(&all_args)
            .current_dir(dir)
            .output()
    } else {
        Command::new("bash")
            .arg(script)
            .args(args)
            .current_dir(dir)
            .output()
    };

    let output = output.unwrap_or_else(|e| panic!("Failed to execute {}: {}", script, e));
    let stdout = String::from_utf8_lossy(&output.stdout).to_string();
    let stderr = String::from_utf8_lossy(&output.stderr).to_string();
    (output.status.success(), stdout, stderr)
}

/// Assert that a command-line tool is available in PATH.
/// Panics with a clear message if not found.
fn require_tool(name: &str) {
    let check = if cfg!(windows) {
        Command::new("where").arg(name).output()
    } else {
        Command::new("which").arg(name).output()
    };

    match check {
        Ok(output) if output.status.success() => {}
        _ => panic!(
            "\n\n\
             ===================================================================\n\
             MISSING BUILD DEPENDENCY: {name}\n\
             ===================================================================\n\
             \n\
             Anvil's cargo tests REQUIRE build-machine dependencies.\n\
             Install '{name}' and re-run.  See 'anvil doctor' for guidance.\n\
             \n\
             ===================================================================\n"
        ),
    }
}

/// Check that at least one C++ compiler is present.
fn require_cpp_compiler() {
    let has_gpp = Command::new(if cfg!(windows) { "where" } else { "which" })
        .arg("g++")
        .output()
        .map(|o| o.status.success())
        .unwrap_or(false);
    let has_clangpp = Command::new(if cfg!(windows) { "where" } else { "which" })
        .arg("clang++")
        .output()
        .map(|o| o.status.success())
        .unwrap_or(false);
    if !has_gpp && !has_clangpp {
        panic!(
            "\n\n\
             ===================================================================\n\
             MISSING BUILD DEPENDENCY: C++ compiler (g++ or clang++)\n\
             ===================================================================\n\
             \n\
             Install g++ or clang++ and re-run.\n\
             \n\
             ===================================================================\n"
        );
    }
}

/// Require cmake + C++ compiler + git (the test script prereqs).
fn require_test_script_deps() {
    require_tool("cmake");
    require_tool("git");
    require_cpp_compiler();
}

/// Require arduino-cli (the build script prereqs).
fn require_build_script_deps() {
    require_tool("arduino-cli");
}

/// Choose the platform-appropriate script path.
fn test_script() -> &'static str {
    if cfg!(windows) { "test\\run_tests.bat" } else { "test/run_tests.sh" }
}

fn build_script() -> &'static str {
    if cfg!(windows) { "build.bat" } else { "build.sh" }
}

/// List directory contents recursively (for diagnostic output on failure).
fn list_dir_recursive(dir: &Path) -> String {
    if !dir.exists() {
        return format!("  (directory does not exist: {})", dir.display());
    }
    let mut lines = Vec::new();
    for entry in walkdir::WalkDir::new(dir)
        .max_depth(4)
        .into_iter()
        .filter_map(|e| e.ok())
    {
        let depth = entry.depth();
        let indent = "  ".repeat(depth);
        let name = entry.file_name().to_string_lossy();
        lines.push(format!("{}{}", indent, name));
    }
    lines.join("\n")
}

// ==========================================================================
// TEST SCRIPT EXECUTION (cmake + Google Test)
//
// Extracts a project, then runs test/run_tests.sh which:
//   1. cmake configures the test/ directory
//   2. FetchContent downloads Google Test
//   3. Compiles C++ unit tests against HAL mocks
//   4. Runs tests via ctest
//
// Required on build machine: cmake, g++ or clang++, git
// ==========================================================================

#[test]
fn test_run_tests_script_executes_successfully() {
    require_test_script_deps();

    let tmp = extract_project("test_exec");

    #[cfg(unix)]
    chmod_scripts(tmp.path());

    let (success, stdout, stderr) = run_script(tmp.path(), test_script());

    // Always print output so CI logs are useful
    println!("--- run_tests stdout ---\n{}", stdout);
    if !stderr.is_empty() {
        eprintln!("--- run_tests stderr ---\n{}", stderr);
    }

    assert!(
        success,
        "test/run_tests script failed!\n\nstdout:\n{}\n\nstderr:\n{}",
        stdout, stderr
    );
}

#[test]
fn test_run_tests_script_google_tests_actually_ran() {
    require_test_script_deps();

    let tmp = extract_project("gtest_verify");

    #[cfg(unix)]
    chmod_scripts(tmp.path());

    let (success, stdout, stderr) = run_script(tmp.path(), test_script());

    assert!(
        success,
        "Test script failed.\nstdout:\n{}\nstderr:\n{}",
        stdout, stderr
    );

    // Verify that Google Test actually executed tests -- not a silent no-op
    let combined = format!("{}{}", stdout, stderr);
    let tests_ran = combined.contains("passed")
        || combined.contains("PASSED")
        || combined.contains("tests passed")
        || combined.contains("100%");
    assert!(
        tests_ran,
        "Output does not indicate any Google Tests actually executed.\n\
         This could mean cmake built but ctest found no registered tests.\n\n\
         stdout:\n{}\n\nstderr:\n{}",
        stdout, stderr
    );
}

#[test]
fn test_run_tests_script_clean_flag_rebuilds() {
    require_test_script_deps();

    let tmp = extract_project("clean_rebuild");

    #[cfg(unix)]
    chmod_scripts(tmp.path());

    // First run -- populates build dir and fetches gtest
    let (success, _, _) = run_script(tmp.path(), test_script());
    assert!(success, "First test run failed");

    // Verify build artifacts exist
    let build_dir = tmp.path().join("test").join("build");
    assert!(
        build_dir.exists(),
        "test/build/ directory should exist after first run"
    );

    // Second run with --clean -- should nuke build dir and rebuild
    let (success, stdout, stderr) =
        run_script_with_args(tmp.path(), test_script(), &["--clean"]);

    println!("--- clean rebuild stdout ---\n{}", stdout);
    if !stderr.is_empty() {
        eprintln!("--- clean rebuild stderr ---\n{}", stderr);
    }

    assert!(
        success,
        "Clean rebuild failed.\nstdout:\n{}\nstderr:\n{}",
        stdout, stderr
    );
}

#[test]
fn test_run_tests_script_produces_test_binary() {
    require_test_script_deps();

    let tmp = extract_project("bin_check");

    #[cfg(unix)]
    chmod_scripts(tmp.path());

    let (success, _, _) = run_script(tmp.path(), test_script());
    assert!(success, "Test script failed");

    // The cmake build should produce a test_unit binary somewhere
    // under test/build/
    let build_dir = tmp.path().join("test").join("build");
    let has_binary = walkdir::WalkDir::new(&build_dir)
        .into_iter()
        .filter_map(|e| e.ok())
        .any(|entry| {
            let name = entry.file_name().to_string_lossy();
            name.starts_with("test_unit")
        });

    assert!(
        has_binary,
        "Expected test_unit binary under test/build/ after running tests.\n\
         Contents of test/build/:\n{}",
        list_dir_recursive(&build_dir)
    );
}

#[test]
fn test_run_tests_idempotent_second_run() {
    // Running the test script twice should succeed both times.
    // Second run reuses the cached build and should be fast.
    require_test_script_deps();

    let tmp = extract_project("idempotent");

    #[cfg(unix)]
    chmod_scripts(tmp.path());

    let (success1, _, _) = run_script(tmp.path(), test_script());
    assert!(success1, "First run failed");

    let (success2, stdout2, stderr2) = run_script(tmp.path(), test_script());
    assert!(
        success2,
        "Second run failed (should be idempotent).\nstdout:\n{}\nstderr:\n{}",
        stdout2, stderr2
    );
}

// ==========================================================================
// BUILD SCRIPT EXECUTION (arduino-cli compile)
//
// Extracts a project, then runs build.sh which:
//   1. Reads .anvil.toml for FQBN, include_dirs, extra_flags
//   2. Invokes arduino-cli compile with those settings
//
// Required on build machine: arduino-cli with arduino:avr core installed
// ==========================================================================

#[test]
fn test_build_script_compiles_sketch() {
    require_build_script_deps();

    let tmp = extract_project("build_test");

    #[cfg(unix)]
    chmod_scripts(tmp.path());

    let (success, stdout, stderr) = run_script(tmp.path(), build_script());

    println!("--- build.sh stdout ---\n{}", stdout);
    if !stderr.is_empty() {
        eprintln!("--- build.sh stderr ---\n{}", stderr);
    }

    assert!(
        success,
        "build script failed!\n\nstdout:\n{}\n\nstderr:\n{}",
        stdout, stderr
    );
}

#[test]
fn test_build_script_produces_compilation_output() {
    require_build_script_deps();

    let tmp = extract_project("compile_output");

    #[cfg(unix)]
    chmod_scripts(tmp.path());

    let (success, stdout, stderr) = run_script(tmp.path(), build_script());
    assert!(
        success,
        "Build script failed.\nstdout:\n{}\nstderr:\n{}",
        stdout, stderr
    );

    // arduino-cli compile produces output indicating sketch size.
    // Look for evidence of successful compilation.
    let combined = format!("{}{}", stdout, stderr);
    let compiled = combined.contains("Sketch uses")
        || combined.contains("bytes")
        || combined.contains("Compiling")
        || combined.contains("Used")
        || combined.contains("compiled");
    assert!(
        compiled,
        "Build output does not indicate a successful arduino-cli compilation.\n\n\
         stdout:\n{}\n\nstderr:\n{}",
        stdout, stderr
    );
}

#[test]
fn test_build_script_idempotent_second_run() {
    require_build_script_deps();

    let tmp = extract_project("build_idem");

    #[cfg(unix)]
    chmod_scripts(tmp.path());

    let (success1, _, _) = run_script(tmp.path(), build_script());
    assert!(success1, "First build failed");

    let (success2, stdout2, stderr2) = run_script(tmp.path(), build_script());
    assert!(
        success2,
        "Second build failed (should be idempotent).\nstdout:\n{}\nstderr:\n{}",
        stdout2, stderr2
    );
}

// ==========================================================================
// COMBINED: build + test scripts both succeed on the same project
//
// Full end-to-end: one extracted project, both scripts pass.
// ==========================================================================

#[test]
fn test_full_project_build_and_test_scripts_both_pass() {
    require_test_script_deps();
    require_build_script_deps();

    let tmp = extract_project("full_e2e");

    #[cfg(unix)]
    chmod_scripts(tmp.path());

    // Build the sketch
    let (build_ok, build_out, build_err) = run_script(tmp.path(), build_script());
    println!("--- build stdout ---\n{}", build_out);
    if !build_err.is_empty() {
        eprintln!("--- build stderr ---\n{}", build_err);
    }
    assert!(
        build_ok,
        "build script failed in full E2E.\nstdout:\n{}\nstderr:\n{}",
        build_out, build_err
    );

    // Run the host-side unit tests
    let (test_ok, test_out, test_err) = run_script(tmp.path(), test_script());
    println!("--- test stdout ---\n{}", test_out);
    if !test_err.is_empty() {
        eprintln!("--- test stderr ---\n{}", test_err);
    }
    assert!(
        test_ok,
        "test script failed in full E2E.\nstdout:\n{}\nstderr:\n{}",
        test_out, test_err
    );
}

// ==========================================================================
// SCRIPT CONTENT SANITY CHECKS
//
// Verify the scripts are well-formed before even executing them.
// ==========================================================================

#[test]
fn test_all_sh_scripts_have_strict_error_handling() {
    let tmp = extract_project("strict_mode");

    let sh_scripts = vec![
        "build.sh",
        "upload.sh",
        "monitor.sh",
        "test/run_tests.sh",
    ];

    for script in &sh_scripts {
        let path = tmp.path().join(script);
        if !path.exists() {
            continue;
        }
        let content = fs::read_to_string(&path)
            .unwrap_or_else(|_| panic!("Failed to read {}", script));

        assert!(
            content.contains("set -e") || content.contains("set -euo pipefail"),
            "{} must use 'set -e' or 'set -euo pipefail' for strict error handling",
            script
        );
    }
}

#[test]
fn test_all_sh_scripts_have_shebangs() {
    let tmp = extract_project("shebang_check");

    let sh_scripts = vec![
        "build.sh",
        "upload.sh",
        "monitor.sh",
        "test/run_tests.sh",
    ];

    for script in &sh_scripts {
        let path = tmp.path().join(script);
        if !path.exists() {
            continue;
        }
        let content = fs::read_to_string(&path)
            .unwrap_or_else(|_| panic!("Failed to read {}", script));

        assert!(
            content.starts_with("#!/"),
            "{} must start with a shebang line (#!/...)",
            script
        );
    }
}

#[test]
fn test_bat_scripts_exist_for_windows_parity() {
    let tmp = extract_project("win_parity");

    // Every .sh should have a matching .bat
    let pairs = vec![
        ("build.sh", "build.bat"),
        ("upload.sh", "upload.bat"),
        ("monitor.sh", "monitor.bat"),
        ("test/run_tests.sh", "test/run_tests.bat"),
    ];

    for (sh, bat) in &pairs {
        let sh_exists = tmp.path().join(sh).exists();
        let bat_exists = tmp.path().join(bat).exists();
        if sh_exists {
            assert!(
                bat_exists,
                "{} exists but {} is missing -- Windows parity broken",
                sh, bat
            );
        }
    }
}

#[test]
fn test_cmake_lists_fetches_google_test() {
    let tmp = extract_project("cmake_gtest");

    let cmake_path = tmp.path().join("test").join("CMakeLists.txt");
    assert!(cmake_path.exists(), "test/CMakeLists.txt must exist");

    let content = fs::read_to_string(&cmake_path).unwrap();

    assert!(
        content.contains("FetchContent") || content.contains("fetchcontent"),
        "CMakeLists.txt should use FetchContent to download Google Test"
    );
    assert!(
        content.contains("googletest") || content.contains("GTest"),
        "CMakeLists.txt should reference Google Test"
    );
}

#[test]
fn test_scripts_all_reference_anvil_toml() {
    let tmp = extract_project("toml_refs");

    // build and upload scripts must read .anvil.toml for configuration
    let config_scripts = vec![
        "build.sh",
        "build.bat",
        "upload.sh",
        "upload.bat",
    ];

    for script in &config_scripts {
        let path = tmp.path().join(script);
        if !path.exists() {
            continue;
        }
        let content = fs::read_to_string(&path)
            .unwrap_or_else(|_| panic!("Failed to read {}", script));

        assert!(
            content.contains(".anvil.toml"),
            "{} should reference .anvil.toml for project configuration",
            script
        );
    }
}

#[test]
fn test_scripts_invoke_arduino_cli_not_anvil() {
    let tmp = extract_project("no_anvil_dep");

    // All scripts must invoke arduino-cli directly, never the anvil binary
    let scripts = vec![
        "build.sh", "build.bat",
        "upload.sh", "upload.bat",
        "monitor.sh", "monitor.bat",
    ];

    for script in &scripts {
        let path = tmp.path().join(script);
        if !path.exists() {
            continue;
        }
        let content = fs::read_to_string(&path)
            .unwrap_or_else(|_| panic!("Failed to read {}", script));

        assert!(
            content.contains("arduino-cli"),
            "{} should invoke arduino-cli directly",
            script
        );

        // No line should shell out to the anvil binary
        let has_anvil_cmd = content.lines().any(|line| {
            let trimmed = line.trim();
            // Skip comments and echo/print lines
            if trimmed.starts_with('#')
                || trimmed.starts_with("::")
                || trimmed.starts_with("echo")
                || trimmed.starts_with("REM")
                || trimmed.starts_with("rem")
            {
                return false;
            }
            // Check for "anvil " as a command invocation
            trimmed.contains("anvil ")
                && !trimmed.contains("anvil.toml")
                && !trimmed.contains("Anvil")
        });
        assert!(
            !has_anvil_cmd,
            "{} should not invoke the anvil binary -- project must be self-contained",
            script
        );
    }
}