various: clean up multiplatform mod resolution; add lockfile management

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: If1fed3ad9f9273266ae6e0e24d57b6996a6a6964

crates/pakker-core/src/model/lockfile.rs

@@ -1,4 +1,7 @@
-use std::{collections::HashMap, path::Path};
+use std::{
+  collections::{HashMap, HashSet},
+  path::Path,
+};
 
 use serde::{Deserialize, Serialize};
 
@@ -656,6 +659,7 @@ impl LockFile {
       lockfile.validate()?;
     }
     lockfile.sort_projects();
+    lockfile.deduplicate_projects();
 
     Ok(lockfile)
   }
@@ -754,7 +758,84 @@ impl LockFile {
   }
 
   pub fn add_project(&mut self, project: Project) {
+    // Check for existing project with overlapping slugs
+    if let Some(existing) = self.projects.iter_mut().find(|p| {
+      p.slug
+        .values()
+        .any(|s| project.slug.values().any(|ps| ps == s))
+    }) {
+      // Merge data into existing project
+      for (platform, slug) in &project.slug {
+        existing
+          .slug
+          .entry(platform.clone())
+          .or_insert_with(|| slug.clone());
+      }
+      for (platform, name) in &project.name {
+        existing
+          .name
+          .entry(platform.clone())
+          .or_insert_with(|| name.clone());
+      }
+      for (platform, id) in &project.id {
+        existing
+          .id
+          .entry(platform.clone())
+          .or_insert_with(|| id.clone());
+      }
+      for file in &project.files {
+        if !existing.files.iter().any(|f| f.file_name == file.file_name) {
+          existing.files.push(file.clone());
+        }
+      }
+      log::debug!(
+        "Merged duplicate project '{}' into existing entry",
+        project.get_name()
+      );
+      self.projects.sort_by_key(super::project::Project::get_name);
+      return;
+    }
+
     self.projects.push(project);
     self.projects.sort_by_key(super::project::Project::get_name);
   }
+
+  /// Remove duplicate projects that share overlapping slugs.
+  /// When duplicates are found, files from the duplicate are merged into
+  /// the kept project. This handles lockfiles that were corrupted before
+  /// `add_project` enforced slug uniqueness.
+  pub fn deduplicate_projects(&mut self) {
+    let mut seen_slugs: HashSet<String> = HashSet::new();
+    let mut slug_to_idx: HashMap<String, usize> = HashMap::new();
+    let mut unique: Vec<Project> = Vec::with_capacity(self.projects.len());
+
+    for project in self.projects.drain(..) {
+      let duplicate_slug =
+        project.slug.values().find(|s| seen_slugs.contains(*s));
+
+      if let Some(dup_slug) = duplicate_slug {
+        log::debug!(
+          "Removed duplicate project '{}' (slug collision: {dup_slug})",
+          project.get_name()
+        );
+        if let Some(&existing_idx) = slug_to_idx.get(dup_slug) {
+          if let Some(existing) = unique.get_mut(existing_idx) {
+            for file in &project.files {
+              if !existing.files.iter().any(|f| f.file_name == file.file_name) {
+                existing.files.push(file.clone());
+              }
+            }
+          }
+        }
+      } else {
+        for slug in project.slug.values() {
+          seen_slugs.insert(slug.clone());
+          slug_to_idx.insert(slug.clone(), unique.len());
+        }
+        unique.push(project);
+      }
+    }
+
+    self.projects = unique;
+  }
 }

crates/pakker-core/src/model/project.rs

@@ -156,32 +156,6 @@ impl Project {
     self.name.insert(platform, name);
   }
 
-  pub fn merge(&mut self, other: Self) {
-    // Merge platform identifiers
-    for (platform, id) in other.id {
-      self.id.entry(platform).or_insert(id);
-    }
-    for (platform, slug) in other.slug {
-      self.slug.entry(platform).or_insert(slug);
-    }
-    for (platform, name) in other.name {
-      self.name.entry(platform).or_insert(name);
-    }
-
-    // Merge pakku links
-    self.pakku_links.extend(other.pakku_links);
-
-    // Merge files
-    for file in other.files {
-      if !self.files.iter().any(|f| f.id == file.id) {
-        self.files.push(file);
-      }
-    }
-
-    // Merge aliases
-    self.aliases.extend(other.aliases);
-  }
-
   /// Merge this project with another, returning a new combined project.
   /// Like Pakku's `Project.plus()`, this is a pure operation that doesn't
   /// modify either project.

crates/pakker-core/src/platform/curseforge.rs

@@ -322,7 +322,9 @@ impl PlatformClient for CurseForgePlatform {
       query_params.push(("modLoaderTypes", loader_str));
     }
 
-    if !query_params.is_empty() {
+    let has_filters = !query_params.is_empty();
+
+    if has_filters {
       let query_string = query_params
         .iter()
         .map(|(k, v)| format!("{k}={v}"))
@@ -350,6 +352,30 @@ impl PlatformClient for CurseForgePlatform {
       .map(|f| Self::convert_file(f, project_id))
       .collect();
 
+    // If server-side filters eliminated all results, retry without them
+    if files.is_empty() && has_filters {
+      let bare_url = format!("{CURSEFORGE_API_BASE}/mods/{project_id}/files");
+      let response = self
+        .client
+        .get(&bare_url)
+        .headers(self.get_headers()?)
+        .send()
+        .await?;
+
+      if !response.status().is_success() {
+        return Err(Self::map_http_error(response.status(), project_id));
+      }
+
+      let result: CurseForgeFilesResponse = response.json().await?;
+      return Ok(
+        result
+          .data
+          .into_iter()
+          .map(|f| Self::convert_file(f, project_id))
+          .collect(),
+      );
+    }
+
     Ok(files)
   }
 

crates/pakker-core/src/platform/modrinth.rs

@@ -222,7 +222,16 @@ impl PlatformClient for ModrinthPlatform {
       url.push_str(&params.join("&"));
     }
 
-    self.request_project_files_url(&url).await
+    let files = self.request_project_files_url(&url).await?;
+
+    // If server-side filters eliminated all results, retry without them
+    if files.is_empty() && !params.is_empty() {
+      let bare_url =
+        format!("{MODRINTH_API_BASE}/project/{project_id}/version");
+      return self.request_project_files_url(&bare_url).await;
+    }
+
+    Ok(files)
   }
 
   async fn request_project_with_files(

crates/pakker-core/src/resolver.rs

@@ -140,7 +140,7 @@ impl DependencyResolver {
     } else {
       let mut merged = projects.remove(0);
       for project in projects {
-        merged.merge(project);
+        merged = merged.merged(project)?;
       }
       Ok(merged)
     }