// file: crates/ksp-config-lib/src/profile.rs
// version: 4

/// Origin of one top-level value in a resolved standard Config profile.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum ConfigValueOrigin {
    /// Value comes from the global section of the specialized document.
    Global,
    /// Value comes from the selected profile object.
    Profile,
}

/// Source that selected the effective profile.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum ConfigProfileSelectionSource {
    /// The document's autonomous `default_profile` selected the profile.
    DefaultProfile,
    /// A caller explicitly requested the profile by `profile_id`.
    Explicit,
    /// A composite document selected the referenced standard document profile.
    Composite,
}

/// Validated standard document resolved to one profile while retaining global/profile provenance.
#[derive(Clone, Debug, PartialEq)]
pub struct ResolvedConfigProfile {
    file_id: crate::ConfigFileId,
    path: std::path::PathBuf,
    profile_id: String,
    selection_source: ConfigProfileSelectionSource,
    globals: serde_json::Map<String, serde_json::Value>,
    profile: serde_json::Map<String, serde_json::Value>,
    effective: serde_json::Map<String, serde_json::Value>,
    origins: std::collections::BTreeMap<String, ConfigValueOrigin>,
}

impl ResolvedConfigProfile {
    /// Returns the logical document identifier from which this profile was resolved.
    #[must_use]
    pub fn file_id(&self) -> &crate::ConfigFileId {
        return &self.file_id;
    }

    /// Returns the physical path of the validated source document.
    #[must_use]
    pub fn path(&self) -> &std::path::Path {
        return self.path.as_path();
    }

    /// Returns the selected unique profile identifier.
    #[must_use]
    pub fn profile_id(&self) -> &str {
        return self.profile_id.as_str();
    }

    /// Returns whether selection came from `default_profile` or an explicit caller request.
    #[must_use]
    pub const fn selection_source(&self) -> ConfigProfileSelectionSource {
        return self.selection_source;
    }

    /// Returns document-global values, excluding the reserved `default_profile` and `profiles` keys.
    #[must_use]
    pub fn globals(&self) -> &serde_json::Map<String, serde_json::Value> {
        return &self.globals;
    }

    /// Returns the selected profile object including its `profile_id`.
    #[must_use]
    pub fn profile(&self) -> &serde_json::Map<String, serde_json::Value> {
        return &self.profile;
    }

    /// Returns a deterministic top-level effective view in which selected profile keys override same-named global keys.
    #[must_use]
    pub fn effective(&self) -> &serde_json::Map<String, serde_json::Value> {
        return &self.effective;
    }

    /// Returns the top-level provenance for an effective key.
    #[must_use]
    pub fn origin(&self, key: &str) -> std::option::Option<ConfigValueOrigin> {
        return self.origins.get(key).copied();
    }

    /// Resolves environment placeholders in the effective view and returns only the real runtime map.
    ///
    /// Use [`Self::resolve_effective_environment_detailed`] when safe value, sensitivity and environment provenance are required. Global/Profile provenance on
    /// this source profile remains unchanged in both cases.
    pub fn resolve_effective_environment(&self, environment: &crate::ConfigEnvironment) -> ksp_core_lib::Result<serde_json::Map<String, serde_json::Value>> {
        let resolved = self.resolve_effective_environment_detailed(environment);
        let resolved = match resolved {
            std::result::Result::Ok(value) => value,
            std::result::Result::Err(error) => return std::result::Result::Err(error),
        };
        return match resolved.value() {
            serde_json::Value::Object(value) => std::result::Result::Ok(value.clone()),
            _ => std::result::Result::Err(ksp_core_lib::Error::new(
                crate::ERROR_CODE_DOCUMENT_SEMANTIC_INVALID,
                "resolved Config profile effective view changed JSON shape",
            )),
        };
    }

    /// Resolves environment placeholders while preserving real/safe JSON trees, strongest sensitivity and JSON-Pointer environment provenance.
    ///
    /// Top-level Global/Profile provenance remains available through [`Self::origin`]; the returned value adds literal/process/`.env`/fallback provenance for
    /// the environment-resolution stage.
    pub fn resolve_effective_environment_detailed(&self, environment: &crate::ConfigEnvironment) -> ksp_core_lib::Result<crate::ResolvedConfigJson> {
        return environment.resolve_json_detailed(&serde_json::Value::Object(self.effective.clone()));
    }
}

impl crate::ConfigDocumentEngine {
    /// Loads, validates and resolves one standard Config document to its default or explicitly requested profile.
    ///
    /// Passing `None` selects the autonomous `default_profile` declared by the document. Passing `Some(profile_id)` selects that profile explicitly.
    /// Environment interpolation is intentionally not applied implicitly by profile selection. Call `ResolvedConfigProfile::resolve_effective_environment` for
    /// a real runtime map or `ResolvedConfigProfile::resolve_effective_environment_detailed` when safe value, sensitivity and provenance are also required.
    pub fn load_resolved_profile(
        &self,
        file_id: &crate::ConfigFileId,
        requested_profile: std::option::Option<&str>,
    ) -> ksp_core_lib::Result<ResolvedConfigProfile> {
        let document = self.load_validated_document(file_id);
        let document = match document {
            std::result::Result::Ok(value) => value,
            std::result::Result::Err(error) => return std::result::Result::Err(error),
        };
        let source = match requested_profile {
            std::option::Option::Some(_) => ConfigProfileSelectionSource::Explicit,
            std::option::Option::None => ConfigProfileSelectionSource::DefaultProfile,
        };
        return resolve_document_profile(&document, requested_profile, source);
    }
}

pub(crate) fn load_resolved_profile_with_source(
    engine: &crate::ConfigDocumentEngine,
    file_id: &crate::ConfigFileId,
    requested_profile: std::option::Option<&str>,
    explicit_source: ConfigProfileSelectionSource,
) -> ksp_core_lib::Result<ResolvedConfigProfile> {
    let document = engine.load_validated_document(file_id);
    let document = match document {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(error) => return std::result::Result::Err(error),
    };
    let source = match requested_profile {
        std::option::Option::Some(_) => explicit_source,
        std::option::Option::None => ConfigProfileSelectionSource::DefaultProfile,
    };
    return resolve_document_profile(&document, requested_profile, source);
}

pub(crate) fn validate_document_profile_contract(document: &crate::ConfigJsonDocument) -> ksp_core_lib::Result<()> {
    let root = match document.value().as_object() {
        std::option::Option::Some(value) => value,
        std::option::Option::None => return std::result::Result::Ok(()),
    };
    let default_profile = root.get("default_profile");
    let profiles = root.get("profiles");
    if default_profile.is_none() && profiles.is_none() {
        return std::result::Result::Ok(());
    }
    let default_profile = match default_profile.and_then(serde_json::Value::as_str) {
        std::option::Option::Some(value) if !value.trim().is_empty() => value,
        _ => return std::result::Result::Err(profile_semantic_error(document, "default_profile must identify a non-empty profile_id")),
    };
    let profiles = match profiles.and_then(serde_json::Value::as_array) {
        std::option::Option::Some(value) if !value.is_empty() => value,
        _ => return std::result::Result::Err(profile_semantic_error(document, "profiles must contain at least one profile object")),
    };
    let mut ids = std::collections::BTreeSet::<String>::new();
    let mut default_found = false;
    for (index, profile) in profiles.iter().enumerate() {
        let object = match profile.as_object() {
            std::option::Option::Some(value) => value,
            std::option::Option::None => {
                return std::result::Result::Err(
                    profile_semantic_error(document, "profile entry must be an object").with_context("profile_index", index.to_string()),
                );
            },
        };
        let profile_id = match object.get("profile_id").and_then(serde_json::Value::as_str) {
            std::option::Option::Some(value) if !value.trim().is_empty() => value,
            _ => {
                return std::result::Result::Err(
                    profile_semantic_error(document, "profile entry must declare a non-empty profile_id").with_context("profile_index", index.to_string()),
                );
            },
        };
        if ids.contains(profile_id) {
            return std::result::Result::Err(
                profile_semantic_error(document, "profile_id values must be unique")
                    .with_context("profile_index", index.to_string())
                    .with_context("profile_id", profile_id),
            );
        }
        ids.insert(profile_id.to_owned());
        if profile_id == default_profile {
            default_found = true;
        }
    }
    if !default_found {
        return std::result::Result::Err(
            profile_semantic_error(document, "default_profile must reference an existing profile_id").with_context("default_profile", default_profile),
        );
    }
    return std::result::Result::Ok(());
}

fn resolve_document_profile(
    document: &crate::ConfigJsonDocument,
    requested_profile: std::option::Option<&str>,
    explicit_source: ConfigProfileSelectionSource,
) -> ksp_core_lib::Result<ResolvedConfigProfile> {
    let root = match document.value().as_object() {
        std::option::Option::Some(value) => value,
        std::option::Option::None => return std::result::Result::Err(profile_semantic_error(document, "profile resolution requires an object document")),
    };
    let default_profile = match root.get("default_profile").and_then(serde_json::Value::as_str) {
        std::option::Option::Some(value) => value,
        std::option::Option::None => return std::result::Result::Err(profile_semantic_error(document, "profile resolution requires default_profile")),
    };
    let (selected_profile, selection_source) = match requested_profile {
        std::option::Option::Some(value) => (value, explicit_source),
        std::option::Option::None => (default_profile, ConfigProfileSelectionSource::DefaultProfile),
    };
    let profiles = match root.get("profiles").and_then(serde_json::Value::as_array) {
        std::option::Option::Some(value) => value,
        std::option::Option::None => return std::result::Result::Err(profile_semantic_error(document, "profile resolution requires profiles")),
    };
    let mut selected: std::option::Option<&serde_json::Map<String, serde_json::Value>> = std::option::Option::None;
    for profile in profiles {
        let object = match profile.as_object() {
            std::option::Option::Some(value) => value,
            std::option::Option::None => continue,
        };
        if object.get("profile_id").and_then(serde_json::Value::as_str) == std::option::Option::Some(selected_profile) {
            selected = std::option::Option::Some(object);
            break;
        }
    }
    let selected = match selected {
        std::option::Option::Some(value) => value,
        std::option::Option::None => {
            return std::result::Result::Err(
                ksp_core_lib::Error::new(crate::ERROR_CODE_PROFILE_NOT_FOUND, "requested Config profile does not exist")
                    .with_context("file_id", document.file_id().as_str())
                    .with_context("path", document.path().to_string_lossy().into_owned())
                    .with_context("profile_id", selected_profile),
            );
        },
    };
    let mut globals = serde_json::Map::<String, serde_json::Value>::new();
    let mut effective = serde_json::Map::<String, serde_json::Value>::new();
    let mut origins = std::collections::BTreeMap::<String, ConfigValueOrigin>::new();
    for (key, value) in root {
        if key != "default_profile" && key != "profiles" {
            globals.insert(key.clone(), value.clone());
            effective.insert(key.clone(), value.clone());
            origins.insert(key.clone(), ConfigValueOrigin::Global);
        }
    }
    let profile = (*selected).clone();
    for (key, value) in &profile {
        effective.insert(key.clone(), value.clone());
        origins.insert(key.clone(), ConfigValueOrigin::Profile);
    }
    return std::result::Result::Ok(ResolvedConfigProfile {
        file_id: document.file_id().clone(),
        path: document.path().to_path_buf(),
        profile_id: selected_profile.to_owned(),
        selection_source,
        globals,
        profile,
        effective,
        origins,
    });
}

fn profile_semantic_error(document: &crate::ConfigJsonDocument, reason: &'static str) -> ksp_core_lib::Error {
    return ksp_core_lib::Error::new(crate::ERROR_CODE_DOCUMENT_SEMANTIC_INVALID, "Config document violates KSP profile invariants")
        .with_context("file_id", document.file_id().as_str())
        .with_context("path", document.path().to_string_lossy().into_owned())
        .with_context("reason", reason);
}

#[cfg(test)]
#[path = "../unit_tests/profile.rs"]
mod tests;