use super::CommitType;
#[derive(Debug)]
pub struct PromptContext {
pub change_summary: String,
pub file_breakdown: String,
pub symbols_added: String,
pub symbols_removed: String,
pub symbols_modified: String,
pub public_api_removed: String,
pub suggested_type: CommitType,
pub suggested_scope: Option<String>,
pub truncated_diff: String,
pub is_mechanical: bool,
pub has_bug_evidence: bool,
pub public_api_removed_count: usize,
pub has_new_public_api: bool,
pub is_dependency_only: bool,
pub file_count: usize,
pub primary_change: Option<String>,
pub group_rationale: Option<String>,
pub metadata_breaking_signals: Vec<String>,
pub locale: Option<String>,
pub history_context: Option<String>,
pub connections: Vec<String>,
}
impl PromptContext {
#[must_use]
pub fn to_prompt(&self) -> String {
let symbols_section = self.format_symbols_section();
let breaking_warning = self.format_breaking_warning();
let evidence_section = self.format_evidence_section();
let constraints_section = self.format_constraints_section();
let connections_section = if self.connections.is_empty() {
String::new()
} else {
format!(
"\nCONNECTIONS:\n{}\n",
self.connections
.iter()
.map(|c| format!(" {}", c))
.collect::<Vec<_>>()
.join("\n")
)
};
let prefix_len = self.suggested_type.as_str().len()
+ self
.suggested_scope
.as_ref()
.map(|s| s.len() + 2)
.unwrap_or(0) + if self.public_api_removed_count > 0 { 1 } else { 0 } + 2; let subject_budget = 72_usize.saturating_sub(prefix_len);
let focus_instruction = if self.file_count > 5 {
"\nFOCUS: This group contains many files. Focus the subject on the single most significant change. Do not try to describe every change — pick the primary one.\n"
} else {
""
};
let primary_change_line = self
.primary_change
.as_ref()
.map(|pc| format!("\nPRIMARY_CHANGE: {}\n", pc))
.unwrap_or_default();
let group_rationale_line = self
.group_rationale
.as_ref()
.map(|gr| format!("GROUP_REASON: {}\n", gr))
.unwrap_or_default();
let locale_instruction = self
.locale
.as_ref()
.map(|lang| {
format!(
"\nLANGUAGE: Write the subject and body in {lang}. \
The commit type, scope, and JSON keys must remain in English.\n"
)
})
.unwrap_or_default();
let history_section = self
.history_context
.as_ref()
.map(|h| format!("\n{}\n", h))
.unwrap_or_default();
let metadata_breaking_section = if self.metadata_breaking_signals.is_empty() {
String::new()
} else {
format!(
"\nWARNING: METADATA BREAKING CHANGES DETECTED:\n{}\n",
self.metadata_breaking_signals
.iter()
.map(|s| format!("- {}", s))
.collect::<Vec<_>>()
.join("\n")
)
};
format!(
r#"Analyze this git diff and generate a commit message.
SUMMARY: {summary}
FILES: {files}
SUGGESTED TYPE: {commit_type}{scope}
{group_rationale}{evidence}{primary_change}{symbols}{connections}
DIFF:
{diff}
{constraints}{breaking}{metadata_breaking}{locale}{focus}{history}
HARD LIMIT: subject must be under {subject_budget} chars (count carefully). Name at least one concrete entity (function, struct, variable) from the diff.
Body: 1-3 sentences on WHY, or null if trivial. breaking_change: only if existing users must change code/config to stay compatible, else null.
Respond with ONLY this JSON:
{{"type": "<type>", "scope": {scope_json}, "subject": "<MUST be under {subject_budget} chars>", "body": null, "breaking_change": null}}"#,
summary = self.change_summary,
files = self.file_breakdown.trim(),
commit_type = self.suggested_type.as_str(),
scope = self
.suggested_scope
.as_ref()
.map(|s| format!("\nSCOPE: {}", s))
.unwrap_or_default(),
evidence = evidence_section,
symbols = symbols_section,
connections = connections_section,
breaking = breaking_warning,
constraints = constraints_section,
focus = focus_instruction,
primary_change = primary_change_line,
group_rationale = group_rationale_line,
metadata_breaking = metadata_breaking_section,
locale = locale_instruction,
history = history_section,
subject_budget = subject_budget,
scope_json = self
.suggested_scope
.as_ref()
.map(|s| format!("\"{}\"", s))
.unwrap_or_else(|| "null".to_string()),
diff = self.truncated_diff,
)
}
fn format_symbols_section(&self) -> String {
let has_added = !self.symbols_added.is_empty();
let has_removed = !self.symbols_removed.is_empty();
let has_modified = !self.symbols_modified.is_empty();
if !has_added && !has_removed && !has_modified {
return String::new();
}
let mut section = String::from("\nSYMBOLS CHANGED:");
if has_added {
section.push_str(&format!(
"\n Added:\n {}",
self.symbols_added.replace('\n', "\n ")
));
}
if has_removed {
section.push_str(&format!(
"\n Removed:\n {}",
self.symbols_removed.replace('\n', "\n ")
));
}
if has_modified {
section.push_str(&format!(
"\n Modified (signature changed):\n {}",
self.symbols_modified.replace('\n', "\n ")
));
}
section.push('\n');
section
}
fn format_breaking_warning(&self) -> String {
if self.public_api_removed.is_empty() {
return String::new();
}
format!(
"\nWARNING: PUBLIC API REMOVED — describe this in breaking_change field:\n {}\n",
self.public_api_removed.replace('\n', "\n ")
)
}
fn format_evidence_section(&self) -> String {
if !self.is_mechanical
&& !self.has_bug_evidence
&& self.public_api_removed_count == 0
&& !self.has_new_public_api
&& !self.is_dependency_only
{
return String::new();
}
let yn = |b: bool| if b { "yes" } else { "no" };
format!(
"\nEVIDENCE:\n\
- Is this a mechanical/formatting change? {}\n\
- Does the diff contain bug-fix comments? {}\n\
- How many public APIs were removed? {}\n\
- Were new public APIs added? {}\n\
- Are all changes in dependency/config files? {}\n",
yn(self.is_mechanical),
yn(self.has_bug_evidence),
self.public_api_removed_count,
yn(self.has_new_public_api),
yn(self.is_dependency_only),
)
}
fn format_constraints_section(&self) -> String {
let mut rules = Vec::new();
if !self.has_bug_evidence {
rules.push(
"- No bug-fix comments found: prefer \"refactor\" over \"fix\". \
Only use \"fix\" if the diff clearly corrects wrong behavior.",
);
}
if self.is_mechanical {
rules.push(
"- Mechanical/formatting change detected: use \"style\" or \"refactor\", not \"feat\" or \"fix\".",
);
}
if self.public_api_removed_count > 0 {
rules.push(
"- Public APIs were removed: set breaking_change to describe what was removed \
(e.g., \"removed `old_fn()`, use `new_fn()` instead\"). \
Never copy labels from this prompt as the description.",
);
}
if self.is_dependency_only {
rules.push("- All changes are in dependency/config files: use \"chore\".");
}
if !self.metadata_breaking_signals.is_empty() {
rules.push(
"- Metadata breaking changes detected (version requirements raised, features removed, etc.): \
set breaking_change to describe the compatibility impact.",
);
}
if rules.is_empty() {
return String::new();
}
format!("\nCONSTRAINTS (must follow):\n{}\n", rules.join("\n"))
}
}