use std::{
    collections::HashMap,
    fs,
    ops::Index,
    path::{Component, Path, PathBuf},
    str::FromStr,
};

use log::warn;

use super::{
    external_libraries::{read_external_libraries, ExternalLibrary},
    gobjects, WorkMode,
};
use crate::{
    analysis::namespaces::{self, Namespace, NsId},
    config::error::TomlHelper,
    env::Env,
    git::{repo_hash, repo_remote_url, toplevel},
    library::{self, Library},
    nameutil::set_crate_name_overrides,
    version::Version,
};

/// Performs canonicalization by removing `foo/../` and `./` components
/// from `path`, without hitting the file system. It does not turn relative
/// paths into absolute paths.
fn normalize_path(path: impl AsRef<Path>) -> PathBuf {
    let mut parts: Vec<Component<'_>> = vec![];

    for component in path.as_ref().components() {
        match (component, parts.last()) {
            (Component::CurDir, _) | (Component::ParentDir, Some(Component::RootDir)) => {}
            (Component::ParentDir, None | Some(Component::ParentDir)) => {
                parts.push(Component::ParentDir);
            }
            (Component::ParentDir, Some(_)) => {
                parts
                    .pop()
                    .expect("Cannot navigate outside of base directory!");
            }
            (c, _) => parts.push(c),
        }
    }
    parts.iter().collect()
}

#[test]
fn test_normalize_path() {
    assert_eq!(normalize_path("foo/../bar").as_os_str(), "bar");
    assert_eq!(normalize_path("foo/./bar").as_os_str(), "foo/bar");
    assert_eq!(normalize_path("./foo").as_os_str(), "foo");
    assert_eq!(
        normalize_path("foo/../bar/baz/../qux").as_os_str(),
        "bar/qux"
    );
    assert_eq!(
        normalize_path("foo/bar/baz/../../qux").as_os_str(),
        "foo/qux"
    );
    assert_eq!(normalize_path("/foo/../bar").as_os_str(), "/bar");
    assert_eq!(normalize_path("/../bar").as_os_str(), "/bar");
    assert_eq!(normalize_path("foo/../../bar").as_os_str(), "../bar");
}

#[derive(Debug)]
pub struct GirVersion {
    pub gir_dir: PathBuf,
    hash: Option<String>,
    url: Option<String>,
}

impl GirVersion {
    fn new(gir_dir: impl AsRef<Path>) -> Self {
        let gir_dir = normalize_path(gir_dir);
        let is_submodule = toplevel(&gir_dir) != Path::new(".").canonicalize().ok();
        Self {
            hash: is_submodule.then(|| repo_hash(&gir_dir).unwrap_or_else(|| "???".to_string())),
            url: is_submodule.then(|| repo_remote_url(&gir_dir)).flatten(),
            gir_dir,
        }
    }

    pub fn get_hash(&self) -> Option<&str> {
        self.hash.as_deref()
    }

    pub fn get_repository_url(&self) -> Option<&str> {
        self.url.as_deref()
    }
}

#[derive(Debug)]
pub struct Config {
    pub work_mode: WorkMode,
    pub girs_dirs: Vec<PathBuf>,
    // Version in girs_dirs, detected by git
    pub girs_version: Vec<GirVersion>,
    pub library_name: String,
    pub library_version: String,
    pub target_path: PathBuf,
    /// Path where files generated in normal and sys mode
    pub auto_path: PathBuf,
    pub doc_target_path: PathBuf,
    pub external_libraries: Vec<ExternalLibrary>,
    pub objects: gobjects::GObjects,
    pub min_cfg_version: Version,
    pub use_gi_docgen: bool,
    pub make_backup: bool,
    pub generate_safety_asserts: bool,
    pub deprecate_by_min_version: bool,
    pub show_statistics: bool,
    pub concurrency: library::Concurrency,
    pub single_version_file: Option<PathBuf>,
    pub trust_return_value_nullability: bool,
    pub disable_format: bool,
    pub split_build_rs: bool,
    pub extra_versions: Vec<Version>,
    pub lib_version_overrides: HashMap<Version, Version>,
    pub feature_dependencies: HashMap<Version, Vec<String>>,
    /// An url that will be inserted into the docs as link that links
    /// to another doc source, for example when builds on docs.rs
    /// are limited due to license issues.
    pub external_docs_url: Option<String>,
}

impl Config {
    pub fn new<'a, S, W>(
        config_file: S,
        work_mode: W,
        girs_dirs: &[String],
        library_name: S,
        library_version: S,
        target_path: S,
        doc_target_path: S,
        make_backup: bool,
        show_statistics: bool,
        disable_format: bool,
    ) -> Result<Self, String>
    where
        S: Into<Option<&'a str>>,
        W: Into<Option<WorkMode>>,
    {
        let config_file: PathBuf = match config_file.into() {
            Some("") | None => "Gir.toml",
            Some(a) => a,
        }
        .into();

        let config_dir = match config_file.parent() {
            Some(path) => path.into(),
            None => PathBuf::new(),
        };

        let toml = match read_toml(&config_file) {
            Ok(toml) => toml,
            Err(e) => {
                return Err(format!(
                    "Error while reading \"{}\": {}",
                    config_file.display(),
                    e
                ))
            }
        };

        let overrides = read_crate_name_overrides(&toml);
        if !overrides.is_empty() {
            set_crate_name_overrides(overrides);
        }

        let work_mode = match work_mode.into() {
            Some(w) => w,
            None => {
                let s = match toml.lookup_str("options.work_mode", "No options.work_mode") {
                    Ok(s) => s,
                    Err(e) => {
                        return Err(format!(
                            "Invalid toml file \"{}\": {}",
                            config_file.display(),
                            e
                        ))
                    }
                };
                WorkMode::from_str(s)?
            }
        };

        let mut girs_dirs: Vec<PathBuf> = girs_dirs
            .iter()
            .filter(|x| !x.is_empty())
            .map(|x| PathBuf::from(&x))
            .collect();
        if girs_dirs.is_empty() {
            let dirs =
                toml.lookup_vec("options.girs_directories", "No options.girs_directories")?;
            for dir in dirs {
                let dir = dir.as_str().ok_or_else(|| {
                    "options.girs_dirs expected to be array of string".to_string()
                })?;
                girs_dirs.push(config_dir.join(dir));
            }
        }
        let mut girs_version = girs_dirs.iter().map(GirVersion::new).collect::<Vec<_>>();
        girs_version.sort_by(|a, b| a.gir_dir.partial_cmp(&b.gir_dir).unwrap());

        let (library_name, library_version) = match (library_name.into(), library_version.into()) {
            (Some(""), Some("")) | (None, None) => (
                toml.lookup_str("options.library", "No options.library")?
                    .to_owned(),
                toml.lookup_str("options.version", "No options.version")?
                    .to_owned(),
            ),
            (Some(""), Some(_)) | (Some(_), Some("")) | (None, Some(_)) | (Some(_), None) => {
                return Err("Library and version can not be specified separately".to_owned())
            }
            (Some(a), Some(b)) => (a.to_owned(), b.to_owned()),
        };

        let target_path: PathBuf = match target_path.into() {
            Some("") | None => {
                let path = toml.lookup_str("options.target_path", "No target path specified")?;
                config_dir.join(path)
            }
            Some(a) => a.into(),
        };

        let generate_builder: bool = toml
            .lookup("options.generate_builder")
            .and_then(|a| a.as_bool())
            .unwrap_or(false);

        let auto_path = match toml.lookup("options.auto_path") {
            Some(p) => target_path.join(p.as_result_str("options.auto_path")?),
            None if work_mode == WorkMode::Normal => target_path.join("src").join("auto"),
            None => target_path.join("src"),
        };
        if work_mode == WorkMode::Normal && auto_path.exists() {
            std::fs::remove_dir_all(&auto_path)
                .map_err(|e| format!("remove_dir_all failed: {e:?}"))?;
        }

        let doc_target_path: PathBuf = match doc_target_path.into() {
            Some("") | None => match toml.lookup("options.doc_target_path") {
                Some(p) => config_dir.join(p.as_result_str("options.doc_target_path")?),
                None => target_path.join("vendor.md"),
            },
            Some(p) => config_dir.join(p),
        };

        let concurrency = match toml.lookup("options.concurrency") {
            Some(v) => v.as_result_str("options.concurrency")?.parse()?,
            None => Default::default(),
        };

        let trust_return_value_nullability =
            match toml.lookup("options.trust_return_value_nullability") {
                Some(v) => v.as_result_bool("options.trust_return_value_nullability")?,
                None => false,
            };

        // options.concurrency is the default of all objects if nothing
        // else is configured
        let mut objects = toml
            .lookup("object")
            .map(|t| {
                gobjects::parse_toml(
                    t,
                    concurrency,
                    generate_builder,
                    trust_return_value_nullability,
                )
            })
            .unwrap_or_default();
        gobjects::parse_status_shorthands(
            &mut objects,
            &toml,
            concurrency,
            generate_builder,
            trust_return_value_nullability,
        );

        let external_libraries = read_external_libraries(&toml)?;

        let min_cfg_version = match toml.lookup("options.min_cfg_version") {
            Some(v) => v.as_result_str("options.min_cfg_version")?.parse()?,
            None => Default::default(),
        };

        let use_gi_docgen = match toml.lookup("options.use_gi_docgen") {
            Some(v) => v.as_result_bool("options.use_gi_docgen")?,
            None => false,
        };

        let generate_safety_asserts = match toml.lookup("options.generate_safety_asserts") {
            Some(v) => v.as_result_bool("options.generate_safety_asserts")?,
            None => false,
        };

        let deprecate_by_min_version = match toml.lookup("options.deprecate_by_min_version") {
            Some(v) => v.as_result_bool("options.deprecate_by_min_version")?,
            None => false,
        };

        let single_version_file = match toml.lookup("options.single_version_file") {
            Some(v) => match v.as_result_bool("options.single_version_file") {
                Ok(false) => None,
                Ok(true) => Some(make_single_version_file(None, &target_path)),
                Err(_) => match v.as_str() {
                    Some(p) => Some(make_single_version_file(Some(p), &target_path)),
                    None => return Err("single_version_file must be bool or string path".into()),
                },
            },
            None => None,
        };

        let disable_format: bool = if disable_format {
            true
        } else {
            match toml.lookup("options.disable_format") {
                Some(v) => v.as_result_bool("options.disable_format")?,
                None => true,
            }
        };

        let split_build_rs = match toml.lookup("options.split_build_rs") {
            Some(v) => v.as_result_bool("options.split_build_rs")?,
            None => false,
        };

        let extra_versions = read_extra_versions(&toml)?;
        let lib_version_overrides = read_lib_version_overrides(&toml)?;
        let feature_dependencies = read_feature_dependencies(&toml)?;
        let external_docs_url = read_external_docs_url(&toml)?;

        Ok(Self {
            work_mode,
            girs_dirs,
            girs_version,
            library_name,
            library_version,
            target_path,
            auto_path,
            doc_target_path,
            external_libraries,
            objects,
            min_cfg_version,
            use_gi_docgen,
            make_backup,
            generate_safety_asserts,
            deprecate_by_min_version,
            show_statistics,
            concurrency,
            single_version_file,
            trust_return_value_nullability,
            disable_format,
            split_build_rs,
            extra_versions,
            lib_version_overrides,
            feature_dependencies,
            external_docs_url,
        })
    }

    pub fn library_full_name(&self) -> String {
        format!("{}-{}", self.library_name, self.library_version)
    }

    pub fn filter_version(&self, version: Option<Version>) -> Option<Version> {
        version.and_then(|v| {
            if v > self.min_cfg_version {
                Some(v)
            } else {
                None
            }
        })
    }

    pub fn find_ext_library(&self, namespace: &Namespace) -> Option<&ExternalLibrary> {
        self.external_libraries
            .iter()
            .find(|lib| lib.crate_name == namespace.crate_name)
    }

    pub fn min_required_version(&self, env: &Env, ns_id: Option<NsId>) -> Option<Version> {
        let ns_id = ns_id.unwrap_or(namespaces::MAIN);
        if ns_id == namespaces::MAIN {
            Some(env.config.min_cfg_version)
        } else {
            let namespace = env.namespaces.index(ns_id);
            self.find_ext_library(namespace)
                .and_then(|lib| lib.min_version)
        }
    }

    pub fn resolve_type_ids(&mut self, library: &Library) {
        gobjects::resolve_type_ids(&mut self.objects, library);
    }

    pub fn check_disable_format(&mut self) {
        if !self.disable_format && !crate::fmt::check_fmt() {
            warn!("Formatter not found, options.disable_format set to true");
            self.disable_format = true;
        }
    }
}

fn read_toml<P: AsRef<Path>>(filename: P) -> Result<toml::Value, String> {
    if !filename.as_ref().is_file() {
        return Err("Config don't exists or not file".to_owned());
    }
    let input = fs::read(&filename)
        .map_err(|e| format!("Failed to read file \"{:?}\": {}", filename.as_ref(), e))?;

    let input = String::from_utf8(input)
        .map_err(|e| format!("File is not valid UTF-8 \"{:?}\": {}", filename.as_ref(), e))?;

    toml::from_str(&input).map_err(|e| {
        format!(
            "Invalid toml format in \"{}\": {}",
            filename.as_ref().display(),
            e
        )
    })
}

fn make_single_version_file(configured: Option<&str>, target_path: &Path) -> PathBuf {
    let file_dir = match configured {
        None | Some("") => target_path.join("src").join("auto"),
        Some(path) => target_path.join(path),
    };

    if file_dir.extension().is_some() {
        file_dir
    } else {
        file_dir.join("versions.txt")
    }
}

fn read_crate_name_overrides(toml: &toml::Value) -> HashMap<String, String> {
    let mut overrides = HashMap::new();
    if let Some(a) = toml
        .lookup("crate_name_overrides")
        .and_then(toml::Value::as_table)
    {
        for (key, value) in a {
            if let Some(s) = value.as_str() {
                overrides.insert(key.clone(), s.to_string());
            }
        }
    };
    overrides
}

fn read_extra_versions(toml: &toml::Value) -> Result<Vec<Version>, String> {
    match toml.lookup("options.extra_versions") {
        Some(a) => a
            .as_result_vec("options.extra_versions")?
            .iter()
            .map(|v| {
                v.as_str().ok_or_else(|| {
                    "options.extra_versions expected to be array of string".to_string()
                })
            })
            .map(|s| s.and_then(str::parse))
            .collect(),
        None => Ok(Vec::new()),
    }
}

fn read_lib_version_overrides(toml: &toml::Value) -> Result<HashMap<Version, Version>, String> {
    let v = match toml.lookup("lib_version_overrides") {
        Some(a) => a.as_result_vec("lib_version_overrides")?,
        None => return Ok(Default::default()),
    };

    let mut map = HashMap::with_capacity(v.len());
    for o in v {
        let cfg = o
            .lookup_str("version", "No version in lib_version_overrides")?
            .parse()?;
        let lib = o
            .lookup_str("lib_version", "No lib_version in lib_version_overrides")?
            .parse()?;
        map.insert(cfg, lib);
    }

    Ok(map)
}

fn read_feature_dependencies(toml: &toml::Value) -> Result<HashMap<Version, Vec<String>>, String> {
    let v = match toml.lookup("feature_dependencies") {
        Some(a) => a.as_result_vec("feature_dependencies")?,
        None => return Ok(Default::default()),
    };

    let mut map = HashMap::with_capacity(v.len());
    for o in v {
        let cfg = o
            .lookup_str("version", "No version in feature_dependencies")?
            .parse()?;
        let dependencies: Result<Vec<String>, String> = o
            .lookup_vec("dependencies", "No dependencies in feature_dependencies")?
            .iter()
            .map(|v| {
                v.as_str()
                    .ok_or_else(|| {
                        "feature_dependencies.dependencies expected to be array of string"
                            .to_string()
                    })
                    .map(str::to_owned)
            })
            .collect();
        map.insert(cfg, dependencies?);
    }

    Ok(map)
}

fn read_external_docs_url(toml: &toml::Value) -> Result<Option<String>, String> {
    Ok(
        if let Some(value) = toml.lookup("options.external_docs_url") {
            let value = value.as_result_str("options.external_docs_url")?;
            Some(value.to_string())
        } else {
            None
        },
    )
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_make_single_version_file() {
        let target_path = Path::new("/tmp/glib");
        assert_eq!(
            make_single_version_file(None, target_path),
            PathBuf::from("/tmp/glib/src/auto/versions.txt")
        );
        assert_eq!(
            make_single_version_file(Some(""), target_path),
            PathBuf::from("/tmp/glib/src/auto/versions.txt")
        );
        assert_eq!(
            make_single_version_file(Some("src"), target_path),
            PathBuf::from("/tmp/glib/src/versions.txt")
        );
        assert_eq!(
            make_single_version_file(Some("src/vers.txt"), target_path),
            PathBuf::from("/tmp/glib/src/vers.txt")
        );
        assert_eq!(
            make_single_version_file(Some("."), target_path),
            PathBuf::from("/tmp/glib/versions.txt")
        );
        assert_eq!(
            make_single_version_file(Some("./_vers.dat"), target_path),
            PathBuf::from("/tmp/glib/_vers.dat")
        );
    }
}