//! ref: composer/src/Composer/Package/Loader/RootPackageLoader.php

use indexmap::IndexMap;
use shirabe_external_packages::composer::pcre::{CaptureKey, Preg};
use shirabe_php_shim::{
    LogicException, RuntimeException, UnexpectedValueException, strtolower, ucfirst,
};

use crate::config::Config;
use crate::io::IOInterface;
use crate::package::CompletePackageInterface;
use crate::package::PackageInterface;
use crate::package::RootAliasPackage;
use crate::package::RootPackage;
use crate::package::RootPackageInterface;
use crate::package::loader::ArrayLoader;
use crate::package::loader::LoaderInterface;
use crate::package::loader::ValidatingArrayLoader;
use crate::package::version::VersionGuesser;
use crate::package::version::VersionParser;
use crate::package::{BasePackage, STABILITIES, SUPPORTED_LINK_TYPES};
use crate::repository::RepositoryFactory;
use crate::repository::RepositoryManager;
use crate::util::Platform;
use crate::util::ProcessExecutor;

#[derive(Debug)]
pub struct RootPackageLoader {
    inner: ArrayLoader,
    manager: std::rc::Rc<std::cell::RefCell<RepositoryManager>>,
    config: std::rc::Rc<std::cell::RefCell<Config>>,
    version_guesser: VersionGuesser,
    io: Option<Box<dyn IOInterface>>,
}

impl RootPackageLoader {
    pub fn new(
        manager: std::rc::Rc<std::cell::RefCell<RepositoryManager>>,
        config: std::rc::Rc<std::cell::RefCell<Config>>,
        parser: Option<VersionParser>,
        version_guesser: Option<VersionGuesser>,
        io: Option<Box<dyn IOInterface>>,
    ) -> Self {
        let inner = ArrayLoader::new(parser, true);
        let version_guesser = version_guesser.unwrap_or_else(|| {
            let mut process_executor = ProcessExecutor::new(io.as_deref().map(|i| i.clone_box()));
            process_executor.enable_async();
            VersionGuesser::new(
                std::rc::Rc::clone(&config),
                std::rc::Rc::new(std::cell::RefCell::new(process_executor)),
                inner.version_parser.clone(),
                io.as_ref().map(|i| i.clone_box()),
            )
        });
        Self {
            inner,
            manager,
            config,
            version_guesser,
            io,
        }
    }

    pub fn load(
        &mut self,
        config: IndexMap<String, Box<shirabe_php_shim::PhpMixed>>,
        class: &str,
        cwd: Option<&str>,
    ) -> anyhow::Result<Box<dyn PackageInterface>> {
        if class != "Composer\\Package\\RootPackage" {
            shirabe_php_shim::trigger_error(
                "The $class arg is deprecated, please reach out to Composer maintainers ASAP if you still need this.",
                shirabe_php_shim::E_USER_DEPRECATED,
            );
        }

        let mut config = config;

        if !config.contains_key("name") {
            config.insert(
                "name".to_string(),
                Box::new(shirabe_php_shim::PhpMixed::String("__root__".to_string())),
            );
        } else if let Some(err) = ValidatingArrayLoader::has_package_naming_error(
            config["name"].as_string().unwrap_or(""),
            false,
        ) {
            return Err(anyhow::anyhow!(RuntimeException {
                message: format!("Your package name {}", err),
                code: 0,
            }));
        }

        let mut auto_versioned = false;
        if !config.contains_key("version") {
            let mut commit: Option<String> = None;

            if Platform::get_env("COMPOSER_ROOT_VERSION").is_some() {
                let version = self.version_guesser.get_root_version_from_env()?;
                config.insert(
                    "version".to_string(),
                    Box::new(shirabe_php_shim::PhpMixed::String(version)),
                );
            } else {
                let cwd_str = cwd
                    .map(|s| s.to_string())
                    .unwrap_or_else(|| Platform::get_cwd(true).unwrap_or_default());
                // TODO(phase-b): config here is IndexMap<String, Box<PhpMixed>> but guess_version
                // expects IndexMap<String, PhpMixed>; pass an empty map as placeholder.
                let unboxed_config: IndexMap<String, shirabe_php_shim::PhpMixed> = IndexMap::new();
                let version_data = self
                    .version_guesser
                    .guess_version(&unboxed_config, &cwd_str)?;
                if let Some(data) = version_data {
                    config.insert(
                        "version".to_string(),
                        Box::new(shirabe_php_shim::PhpMixed::String(
                            data.pretty_version.clone().unwrap_or_default(),
                        )),
                    );
                    config.insert(
                        "version_normalized".to_string(),
                        Box::new(shirabe_php_shim::PhpMixed::String(
                            data.version.clone().unwrap_or_default(),
                        )),
                    );
                    commit = data.commit;
                }
            }

            if !config.contains_key("version") {
                if let Some(ref io) = self.io {
                    let name = config["name"].as_string().unwrap_or("");
                    let package_type = config.get("type").and_then(|v| v.as_string()).unwrap_or("");
                    if name != "__root__" && package_type != "project" {
                        io.warning(&format!(
                            "Composer could not detect the root package ({}) version, defaulting to '1.0.0'. See https://getcomposer.org/root-version",
                            name
                        ), &[]);
                    }
                }
                config.insert(
                    "version".to_string(),
                    Box::new(shirabe_php_shim::PhpMixed::String("1.0.0".to_string())),
                );
                auto_versioned = true;
            }

            if let Some(commit_hash) = commit {
                let mut source = IndexMap::new();
                source.insert(
                    "type".to_string(),
                    Box::new(shirabe_php_shim::PhpMixed::String(String::new())),
                );
                source.insert(
                    "url".to_string(),
                    Box::new(shirabe_php_shim::PhpMixed::String(String::new())),
                );
                source.insert(
                    "reference".to_string(),
                    Box::new(shirabe_php_shim::PhpMixed::String(commit_hash.clone())),
                );
                config.insert(
                    "source".to_string(),
                    Box::new(shirabe_php_shim::PhpMixed::Array(source)),
                );

                let mut dist = IndexMap::new();
                dist.insert(
                    "type".to_string(),
                    Box::new(shirabe_php_shim::PhpMixed::String(String::new())),
                );
                dist.insert(
                    "url".to_string(),
                    Box::new(shirabe_php_shim::PhpMixed::String(String::new())),
                );
                dist.insert(
                    "reference".to_string(),
                    Box::new(shirabe_php_shim::PhpMixed::String(commit_hash)),
                );
                config.insert(
                    "dist".to_string(),
                    Box::new(shirabe_php_shim::PhpMixed::Array(dist)),
                );
            }
        }

        // TODO(phase-b): config is IndexMap<String, Box<PhpMixed>> but LoaderInterface::load
        // expects IndexMap<String, PhpMixed>; pass empty placeholder.
        let unboxed_config: IndexMap<String, shirabe_php_shim::PhpMixed> = IndexMap::new();
        let mut package = self.inner.load(
            unboxed_config,
            Some("Composer\\Package\\RootPackage".to_string()),
        )?;

        // TODO(phase-b): as_any_mut is not available on BasePackage; downcast via Any is not
        // possible without it. Skipping real downcast and using todo!() placeholder.
        let real_package: &mut RootPackage = {
            let _ = &mut package;
            todo!("downcast Box<dyn BasePackage> to &mut RootPackage requires as_any_mut on trait")
        };

        if auto_versioned {
            // TODO(phase-b): replace_version is an inherent method on Package, not exposed via trait.
            let _ = real_package;
            todo!("replace_version is not accessible through RootPackage's embedded Package");
        }

        if let Some(min_stability) = config.get("minimum-stability").and_then(|v| v.as_string()) {
            real_package.set_minimum_stability(
                VersionParser::normalize_stability(min_stability).unwrap_or_default(),
            );
        }

        let mut aliases: Vec<IndexMap<String, String>> = vec![];
        let mut stability_flags: IndexMap<String, i64> = IndexMap::new();
        let mut references: IndexMap<String, String> = IndexMap::new();

        for link_type in ["require", "require-dev"] {
            if config.contains_key(link_type) {
                let link_info = &SUPPORTED_LINK_TYPES[link_type];
                let _method = format!("get_{}", link_info.method);
                // TODO(phase-b): PHP uses dynamic method dispatch ($realPackage->{$method}()).
                // We need a Rust-side equivalent (e.g. a match on link_type) to collect Links.
                let links: IndexMap<String, String> = IndexMap::new();
                aliases = self.extract_aliases(&links, aliases);
                stability_flags = Self::extract_stability_flags(
                    &links,
                    real_package.get_minimum_stability(),
                    stability_flags,
                );
                references = Self::extract_references(&links, references);

                let package_name = config["name"].as_string().unwrap_or("").to_string();
                if links.contains_key(&package_name) {
                    return Err(anyhow::anyhow!(RuntimeException {
                        message: format!(
                            "Root package '{}' cannot require itself in its composer.json\nDid you accidentally name your root package after an external package?",
                            package_name
                        ),
                        code: 0,
                    }));
                }
            }
        }

        for link_type in SUPPORTED_LINK_TYPES.keys() {
            if let Some(section) = config.get(*link_type) {
                if let Some(section_map) = section.as_array() {
                    for (link_name, _constraint) in section_map {
                        if let Some(err) =
                            ValidatingArrayLoader::has_package_naming_error(link_name, true)
                        {
                            return Err(anyhow::anyhow!(RuntimeException {
                                message: format!("{}.{}", link_type, err),
                                code: 0,
                            }));
                        }
                    }
                }
            }
        }

        real_package.set_aliases(aliases);
        real_package.set_stability_flags(stability_flags);
        real_package.set_references(references);

        if let Some(prefer_stable) = config.get("prefer-stable").and_then(|v| v.as_bool()) {
            real_package.set_prefer_stable(prefer_stable);
        }

        if let Some(pkg_config) = config.get("config").and_then(|v| v.as_array()) {
            real_package.set_config(
                pkg_config
                    .iter()
                    .map(|(k, v)| (k.clone(), (**v).clone()))
                    .collect(),
            );
        }

        let repos = RepositoryFactory::default_repos(
            None,
            Some(std::rc::Rc::clone(&self.config)),
            Some(&mut *self.manager.borrow_mut()),
        )?;
        for (_, repo) in repos {
            self.manager.borrow_mut().add_repository(repo);
        }
        // TODO(phase-b): Config::get_repositories returns IndexMap<String, PhpMixed>, but
        // set_repositories expects Vec<IndexMap<String, PhpMixed>>; pass empty placeholder.
        real_package.set_repositories(Vec::new());
        let _ = self.config.borrow().get_repositories();

        Ok(package)
    }

    fn extract_aliases(
        &self,
        requires: &IndexMap<String, String>,
        mut aliases: Vec<IndexMap<String, String>>,
    ) -> Vec<IndexMap<String, String>> {
        for (req_name, req_version) in requires {
            let mut m: IndexMap<CaptureKey, String> = IndexMap::new();
            if Preg::is_match_strict_groups3(
                r"(?:^|\| *|, *)([^,\s#|]+)(?:#[^ ]+)? +as +([^,\s|]+)(?:$| *\|| *,)",
                req_version,
                Some(&mut m),
            )
            .unwrap_or(false)
            {
                let m1 = m.get(&CaptureKey::ByIndex(1)).cloned().unwrap_or_default();
                let m2 = m.get(&CaptureKey::ByIndex(2)).cloned().unwrap_or_default();
                let mut alias = IndexMap::new();
                alias.insert("package".to_string(), strtolower(req_name));
                alias.insert(
                    "version".to_string(),
                    self.inner
                        .version_parser
                        .normalize(&m1, Some(req_version))
                        .unwrap_or_default(),
                );
                alias.insert("alias".to_string(), m2.clone());
                alias.insert(
                    "alias_normalized".to_string(),
                    self.inner
                        .version_parser
                        .normalize(&m2, Some(req_version))
                        .unwrap_or_default(),
                );
                aliases.push(alias);
            } else if req_version.contains(" as ") {
                return {
                    panic!(
                        "{}",
                        UnexpectedValueException {
                            message: format!(
                                "Invalid alias definition in \"{}\": \"{}\". Aliases should be in the form \"exact-version as other-exact-version\".",
                                req_name, req_version
                            ),
                            code: 0,
                        }
                        .message
                    )
                };
            }
        }
        aliases
    }

    pub fn extract_stability_flags(
        requires: &IndexMap<String, String>,
        minimum_stability: &str,
        mut stability_flags: IndexMap<String, i64>,
    ) -> IndexMap<String, i64> {
        let stabilities = &*STABILITIES;
        let minimum_stability_val = stabilities[minimum_stability];

        for (req_name, req_version) in requires {
            let mut constraints: Vec<String> = vec![];

            let or_split = Preg::split(r"\s*\|\|?\s*", req_version.trim()).unwrap_or_default();
            for or_constraint in &or_split {
                let and_split = Preg::split(
                    r"(?<!^|as|[=>< ,]) *(?<!-)[, ](?!-) *(?!,|as|$)",
                    or_constraint,
                )
                .unwrap_or_default();
                for and_constraint in and_split {
                    constraints.push(and_constraint);
                }
            }

            let stability_names: Vec<&str> = stabilities.keys().copied().collect();
            let pattern = format!("^[^@]*?@({})$", stability_names.join("|"));

            let mut matched = false;
            for constraint in &constraints {
                let mut m: IndexMap<CaptureKey, String> = IndexMap::new();
                if Preg::is_match_strict_groups3(&pattern, constraint, Some(&mut m))
                    .unwrap_or(false)
                {
                    let name = strtolower(req_name);
                    let m1 = m.get(&CaptureKey::ByIndex(1)).cloned().unwrap_or_default();
                    let normalized_m1 = VersionParser::normalize_stability(&m1).unwrap_or_default();
                    let stability = stabilities[normalized_m1.as_str()];

                    if stability_flags.get(&name).copied().unwrap_or(i64::MAX) > stability {
                        continue;
                    }
                    stability_flags.insert(name, stability);
                    matched = true;
                }
            }

            if matched {
                continue;
            }

            for constraint in &constraints {
                let req_version_stripped =
                    Preg::replace(r"^([^,\s@]+) as .+$", "$1", constraint).unwrap_or_default();
                if Preg::is_match(r"^[^,\s@]+$", &req_version_stripped).unwrap_or(false) {
                    let stability_name = VersionParser::parse_stability(&req_version_stripped);
                    if stability_name != "stable" {
                        let name = strtolower(req_name);
                        let stability = stabilities[stability_name.as_str()];
                        if stability_flags.get(&name).copied().unwrap_or(i64::MAX) > stability
                            || minimum_stability_val > stability
                        {
                            continue;
                        }
                        stability_flags.insert(name, stability);
                    }
                }
            }
        }

        stability_flags
    }

    pub fn extract_references(
        requires: &IndexMap<String, String>,
        mut references: IndexMap<String, String>,
    ) -> IndexMap<String, String> {
        for (req_name, req_version) in requires {
            let req_version =
                Preg::replace(r"^([^,\s@]+) as .+$", "$1", req_version).unwrap_or_default();
            let mut m: IndexMap<CaptureKey, String> = IndexMap::new();
            if Preg::is_match_strict_groups3(r"^[^,\s@]+?#([a-f0-9]+)$", &req_version, Some(&mut m))
                .unwrap_or(false)
            {
                if VersionParser::parse_stability(&req_version) == "dev" {
                    let name = strtolower(req_name);
                    references.insert(
                        name,
                        m.get(&CaptureKey::ByIndex(1)).cloned().unwrap_or_default(),
                    );
                }
            }
        }
        references
    }
}