//! TOML-deserializable ty configuration, similar to `ty.toml`, to be able to
//! control some configuration options from Markdown files. For now, this supports the
//! following limited structure:
//!
//! ```toml
//! log = true # or log = "ty=WARN"
//!
//! [environment]
//! python-version = "3.10"
//!
//! [project]
//! dependencies = ["pydantic==2.12.2"]
//! ```

use anyhow::Context;
use ruff_db::system::{SystemPath, SystemPathBuf};
use ruff_python_ast::PythonVersion;
use serde::{Deserialize, Serialize};
use ty_python_semantic::PythonPlatform;

#[derive(Deserialize, Debug, Default, Clone)]
#[serde(rename_all = "kebab-case", deny_unknown_fields)]
pub(crate) struct MarkdownTestConfig {
    pub(crate) environment: Option<Environment>,

    pub(crate) log: Option<Log>,

    /// The [`ruff_db::system::System`] to use for tests.
    ///
    /// Defaults to the case-sensitive [`ruff_db::system::InMemorySystem`].
    pub(crate) system: Option<SystemKind>,

    /// Project configuration for installing external dependencies.
    pub(crate) project: Option<Project>,
}

impl MarkdownTestConfig {
    pub(crate) fn from_str(s: &str) -> anyhow::Result<Self> {
        toml::from_str(s).context("Error while parsing Markdown TOML config")
    }

    pub(crate) fn python_version(&self) -> Option<PythonVersion> {
        self.environment.as_ref()?.python_version
    }

    pub(crate) fn python_platform(&self) -> Option<PythonPlatform> {
        self.environment.as_ref()?.python_platform.clone()
    }

    pub(crate) fn typeshed(&self) -> Option<&SystemPath> {
        self.environment.as_ref()?.typeshed.as_deref()
    }

    pub(crate) fn extra_paths(&self) -> Option<&[SystemPathBuf]> {
        self.environment.as_ref()?.extra_paths.as_deref()
    }

    pub(crate) fn python(&self) -> Option<&SystemPath> {
        self.environment.as_ref()?.python.as_deref()
    }

    pub(crate) fn dependencies(&self) -> Option<&[String]> {
        self.project.as_ref()?.dependencies.as_deref()
    }
}

#[derive(Deserialize, Debug, Default, Clone)]
#[serde(rename_all = "kebab-case", deny_unknown_fields)]
pub(crate) struct Environment {
    /// Target Python version to assume when resolving types.
    ///
    /// The Python version affects allowed syntax, type definitions of the standard library, and
    /// type definitions of first- and third-party modules that are conditional on the Python version.
    ///
    /// By default, the Python version is inferred as the lower bound of the project's
    /// `requires-python` field from the `pyproject.toml`, if available. Otherwise, the latest
    /// stable version supported by ty is used (see `ty check --help` output).
    ///
    /// ty will not infer the Python version from the Python environment at this time.
    pub(crate) python_version: Option<PythonVersion>,

    /// Target platform to assume when resolving types.
    pub(crate) python_platform: Option<PythonPlatform>,

    /// Path to a custom typeshed directory.
    pub(crate) typeshed: Option<SystemPathBuf>,

    /// Additional search paths to consider when resolving modules.
    pub(crate) extra_paths: Option<Vec<SystemPathBuf>>,

    /// Path to the Python environment.
    ///
    /// ty uses the Python environment to resolve type information and third-party dependencies.
    ///
    /// If a path to a Python interpreter is provided, e.g., `.venv/bin/python3`, ty will attempt to
    /// find an environment two directories up from the interpreter's path, e.g., `.venv`. At this
    /// time, ty does not invoke the interpreter to determine the location of the environment. This
    /// means that ty will not resolve dynamic executables such as a shim.
    ///
    /// ty will search in the resolved environment's `site-packages` directories for type
    /// information and third-party imports.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub python: Option<SystemPathBuf>,
}

#[derive(Deserialize, Debug, Clone)]
#[serde(untagged)]
pub(crate) enum Log {
    /// Enable logging with tracing when `true`.
    Bool(bool),
    /// Enable logging and only show filters that match the given [env-filter](https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html)
    Filter(String),
}

/// The system to use for tests.
#[derive(Copy, Clone, Debug, PartialEq, Eq, Deserialize, Serialize, Default)]
#[serde(rename_all = "kebab-case")]
pub(crate) enum SystemKind {
    /// Use an in-memory system with a case-sensitive file system.
    ///
    /// This is recommended for all tests because it's fast.
    #[default]
    InMemory,

    /// Use the os system.
    ///
    /// This system should only be used when testing system or OS specific behavior.
    Os,
}

/// Project configuration for tests that need external dependencies.
#[derive(Deserialize, Debug, Default, Clone)]
#[serde(rename_all = "kebab-case", deny_unknown_fields)]
pub(crate) struct Project {
    /// List of Python package dependencies in `pyproject.toml` format.
    ///
    /// These will be installed using `uv sync` into a temporary virtual environment.
    /// The site-packages directory will then be copied into the test's filesystem.
    ///
    /// Example: `dependencies = ["pydantic==2.12.2"]`
    pub(crate) dependencies: Option<Vec<String>>,
}