braze-sync 0.2.1

//! Pure structural diff layer. No I/O.
//!
//! See IMPLEMENTATION.md §6.6 and §11. The shape of [`DiffOp`] and
//! [`ResourceDiff`] is the central design contract: every diff site in the
//! crate goes through these types so that adding a resource forces all
//! match arms to be updated by the compiler.

use crate::resource::ResourceKind;

pub mod catalog;
pub mod content_block;
pub mod custom_attribute;
pub mod email_template;
pub mod orphan;

/// A diff operation on a single entity. Polymorphic over the entity type so
/// the same vocabulary applies to whole resources, individual fields, etc.
#[derive(Debug, Clone, PartialEq)]
pub enum DiffOp<T> {
    Added(T),
    Removed(T),
    Modified { from: T, to: T },
    Unchanged,
}

impl<T> DiffOp<T> {
    pub fn is_change(&self) -> bool {
        !matches!(self, Self::Unchanged)
    }

    pub fn is_destructive(&self) -> bool {
        matches!(self, Self::Removed(_))
    }
}

/// Per-resource-kind diff result.
#[derive(Debug, Clone)]
pub enum ResourceDiff {
    CatalogSchema(catalog::CatalogSchemaDiff),
    CatalogItems(catalog::CatalogItemsDiff),
    ContentBlock(content_block::ContentBlockDiff),
    EmailTemplate(email_template::EmailTemplateDiff),
    CustomAttribute(custom_attribute::CustomAttributeDiff),
}

impl ResourceDiff {
    pub fn kind(&self) -> ResourceKind {
        match self {
            Self::CatalogSchema(_) => ResourceKind::CatalogSchema,
            Self::CatalogItems(_) => ResourceKind::CatalogItems,
            Self::ContentBlock(_) => ResourceKind::ContentBlock,
            Self::EmailTemplate(_) => ResourceKind::EmailTemplate,
            Self::CustomAttribute(_) => ResourceKind::CustomAttribute,
        }
    }

    pub fn name(&self) -> &str {
        match self {
            Self::CatalogSchema(d) => &d.name,
            Self::CatalogItems(d) => &d.catalog_name,
            Self::ContentBlock(d) => &d.name,
            Self::EmailTemplate(d) => &d.name,
            Self::CustomAttribute(d) => &d.name,
        }
    }

    pub fn has_changes(&self) -> bool {
        match self {
            Self::CatalogSchema(d) => d.has_changes(),
            Self::CatalogItems(d) => d.has_changes(),
            Self::ContentBlock(d) => d.has_changes(),
            Self::EmailTemplate(d) => d.has_changes(),
            Self::CustomAttribute(d) => d.has_changes(),
        }
    }

    pub fn has_destructive(&self) -> bool {
        match self {
            Self::CatalogSchema(d) => d.has_destructive(),
            Self::CatalogItems(d) => d.has_destructive(),
            // Content Block / Email Template have no DELETE API. "Destructive"
            // for these resources is reframed as orphan tracking (§11.6); the
            // apply path performs no destructive call.
            Self::ContentBlock(_) => false,
            Self::EmailTemplate(_) => false,
            // Custom Attribute "removal" is only a deprecation flag toggle.
            Self::CustomAttribute(_) => false,
        }
    }

    pub fn is_orphan(&self) -> bool {
        match self {
            Self::ContentBlock(d) => d.is_orphan(),
            Self::EmailTemplate(d) => d.is_orphan(),
            _ => false,
        }
    }
}

#[derive(Debug, Clone, Default)]
pub struct DiffSummary {
    pub diffs: Vec<ResourceDiff>,
}

impl DiffSummary {
    pub fn changed_count(&self) -> usize {
        self.diffs.iter().filter(|d| d.has_changes()).count()
    }

    pub fn destructive_count(&self) -> usize {
        self.diffs.iter().filter(|d| d.has_destructive()).count()
    }

    pub fn orphan_count(&self) -> usize {
        self.diffs.iter().filter(|d| d.is_orphan()).count()
    }

    pub fn in_sync_count(&self) -> usize {
        self.diffs.iter().filter(|d| !d.has_changes()).count()
    }
}