use std::path::PathBuf;
use std::process::Command;

struct Sandbox {
    path: PathBuf,
}

impl Sandbox {
    fn new(name: &str) -> Self {
        let path = std::env::temp_dir().join(format!("doot-test-{}", name));
        if path.exists() {
            std::fs::remove_dir_all(&path).unwrap();
        }
        std::fs::create_dir_all(&path).unwrap();
        Self { path }
    }

    fn run(&self, args: &[&str]) -> std::process::Output {
        let doot = env!("CARGO_BIN_EXE_doot");
        Command::new(doot)
            .args(args)
            .env("DOOT_HOME", &self.path)
            .env("DOOT_TEST_MODE", "1")
            .output()
            .expect("failed to run doot")
    }

    fn config_dir(&self) -> PathBuf {
        self.path.join(".config/doot")
    }

    fn state_dir(&self) -> PathBuf {
        self.path.join(".local/state/doot")
    }

    fn config_file(&self) -> PathBuf {
        self.config_dir().join("doot.doot")
    }

    fn write_config(&self, content: &str) {
        std::fs::create_dir_all(self.config_dir()).unwrap();
        std::fs::write(self.config_file(), content).unwrap();
    }

    fn write_source(&self, path: &str, content: &str) {
        let full_path = self.config_dir().join(path);
        if let Some(parent) = full_path.parent() {
            std::fs::create_dir_all(parent).unwrap();
        }
        std::fs::write(full_path, content).unwrap();
    }

    fn is_symlink(&self, path: &PathBuf) -> bool {
        path.is_symlink()
    }

    fn symlink_target(&self, path: &PathBuf) -> Option<PathBuf> {
        std::fs::read_link(path).ok()
    }
}

impl Drop for Sandbox {
    fn drop(&mut self) {
        let _ = std::fs::remove_dir_all(&self.path);
    }
}

#[test]
fn test_init_creates_structure() {
    let sandbox = Sandbox::new("init");
    let output = sandbox.run(&["init"]);

    assert!(output.status.success(), "init failed: {:?}", output);
    assert!(sandbox.config_file().exists(), "config file not created");
    assert!(sandbox.config_dir().join("config").exists(), "config dir not created");
    assert!(sandbox.state_dir().join("backups").exists(), "backups dir not created");
    assert!(sandbox.state_dir().join("snapshots").exists(), "snapshots dir not created");
}

#[test]
fn test_check_valid_config() {
    let sandbox = Sandbox::new("check-valid");
    sandbox.write_config(r#"
package: "ripgrep"
package: "fd"
"#);

    let output = sandbox.run(&["check"]);
    assert!(output.status.success(), "check failed: {:?}", output);
}

#[test]
fn test_apply_dry_run() {
    let sandbox = Sandbox::new("apply-dry");
    sandbox.write_config(r#"
dotfile:
    source = "config/test.conf"
    target = "~/.config/test/test.conf"
"#);
    sandbox.write_source("config/test.conf", "test content");

    let output = sandbox.run(&["apply", "-n"]);
    assert!(output.status.success(), "apply -n failed: {:?}", output);

    let target = sandbox.path.join(".config/test/test.conf");
    assert!(!target.exists(), "dry run should not create files");
}

#[test]
fn test_apply_creates_symlink() {
    let sandbox = Sandbox::new("apply-symlink");
    sandbox.write_config(r#"
dotfile:
    source = "config/app.conf"
    target = "~/.config/app/app.conf"
    deploy = "link"
"#);
    sandbox.write_source("config/app.conf", "app config content");

    let output = sandbox.run(&["apply"]);
    assert!(output.status.success(), "apply failed: {:?}", output);

    let target = sandbox.path.join(".config/app/app.conf");
    assert!(sandbox.is_symlink(&target), "target should be symlink");

    let expected_source = sandbox.config_dir().join("config/app.conf");
    assert_eq!(
        sandbox.symlink_target(&target),
        Some(expected_source),
        "symlink should point to source"
    );
}

#[test]
fn test_apply_unchanged_on_rerun() {
    let sandbox = Sandbox::new("apply-unchanged");
    sandbox.write_config(
        "dotfile:\n    source = \"config/app.conf\"\n    target = \"~/.config/app/app.conf\"\n    deploy = \"link\"\n",
    );
    sandbox.write_source("config/app.conf", "content");

    let first = sandbox.run(&["apply"]);
    assert!(first.status.success(), "first apply failed");

    let second = sandbox.run(&["apply"]);
    assert!(second.status.success(), "second apply failed");

    // Second apply should succeed (symlink already exists and points correctly)
    let target = sandbox.path.join(".config/app/app.conf");
    assert!(target.is_symlink(), "target should still be symlink after second apply");
}

#[test]
fn test_apply_creates_copy() {
    let sandbox = Sandbox::new("apply-copy");
    sandbox.write_config(r#"
dotfile:
    source = "config/app.conf"
    target = "~/.config/app/app.conf"
"#);
    sandbox.write_source("config/app.conf", "app config content");

    let output = sandbox.run(&["apply"]);
    assert!(output.status.success(), "apply failed: {:?}", output);

    let target = sandbox.path.join(".config/app/app.conf");
    assert!(target.exists(), "target should exist");
    assert!(!target.is_symlink(), "target should be a copy, not a symlink");

    let content = std::fs::read_to_string(&target).unwrap();
    assert_eq!(content, "app config content", "content should match source");
}

#[test]
fn test_apply_copy_unchanged_on_rerun() {
    let sandbox = Sandbox::new("apply-copy-unchanged");
    sandbox.write_config(
        "dotfile:\n    source = \"config/app.conf\"\n    target = \"~/.config/app/app.conf\"\n",
    );
    sandbox.write_source("config/app.conf", "content");

    let first = sandbox.run(&["apply"]);
    assert!(first.status.success(), "first apply failed");

    let second = sandbox.run(&["apply"]);
    assert!(second.status.success(), "second apply failed");

    let target = sandbox.path.join(".config/app/app.conf");
    assert!(target.exists(), "target should exist after second apply");
    assert!(!target.is_symlink(), "target should still be a copy");
}

#[test]
fn test_status_shows_state() {
    let sandbox = Sandbox::new("status");
    sandbox.write_config(r#"
dotfile:
    source = "config/app.conf"
    target = "~/.config/app/app.conf"
"#);
    sandbox.write_source("config/app.conf", "content");
    sandbox.run(&["apply"]);

    let output = sandbox.run(&["status"]);
    assert!(output.status.success(), "status failed: {:?}", output);
}

#[test]
fn test_snapshot_and_rollback() {
    let sandbox = Sandbox::new("snapshot");
    sandbox.write_config(r#"
dotfile:
    source = "config/app.conf"
    target = "~/.config/app/app.conf"
"#);
    sandbox.write_source("config/app.conf", "v1");
    sandbox.run(&["apply"]);

    let snap_output = sandbox.run(&["snapshot", "v1"]);
    assert!(snap_output.status.success(), "snapshot failed: {:?}", snap_output);

    let snapshot_file = sandbox.state_dir().join("snapshots/v1.json");
    assert!(snapshot_file.exists(), "snapshot file not created");
}

#[test]
fn test_dotfile_with_when_condition() {
    let sandbox = Sandbox::new("conditional");

    // Test that 'when' condition works - only deploy if condition is true
    let config = r#"dotfile:
    source = "config/test.conf"
    target = "~/.config/test.conf"
    when = true
"#;
    sandbox.write_config(config);
    sandbox.write_source("config/test.conf", "test content");

    let output = sandbox.run(&["apply"]);
    assert!(output.status.success(), "apply failed: {:?}", output);

    let target = sandbox.path.join(".config/test.conf");
    assert!(target.exists(), "file should be deployed when condition is true");
}

#[test]
fn test_dotfile_when_false_skips() {
    let sandbox = Sandbox::new("when-false");

    let config = r#"dotfile:
    source = "config/skip.conf"
    target = "~/.config/skip.conf"
    when = false
"#;
    sandbox.write_config(config);
    sandbox.write_source("config/skip.conf", "should not deploy");

    let output = sandbox.run(&["apply"]);
    assert!(output.status.success(), "apply failed: {:?}", output);

    let target = sandbox.path.join(".config/skip.conf");
    assert!(!target.exists(), "file should NOT be deployed when condition is false");
}

#[test]
fn test_diff_shows_changes() {
    let sandbox = Sandbox::new("diff");
    sandbox.write_config(r#"
dotfile:
    source = "config/app.conf"
    target = "~/.config/app/app.conf"
"#);
    sandbox.write_source("config/app.conf", "new content");

    let target_dir = sandbox.path.join(".config/app");
    std::fs::create_dir_all(&target_dir).unwrap();
    std::fs::write(target_dir.join("app.conf"), "old content").unwrap();

    let output = sandbox.run(&["diff"]);
    assert!(output.status.success(), "diff failed: {:?}", output);
}