forge-orchestrator 1.7.0

use super::{DriftScore, ForgeBrain, KnowledgeCategory};
use crate::core::task::{AgentType, Task};

/// Rule-based brain — no LLM calls, pure heuristics.
/// This is the free tier / fallback brain.
pub struct RuleBasedBrain;

/// Tasks are user-facing by default. Only tasks matching these internal/infra
/// keywords are excluded from UAT generation. This inverts the old approach
/// (whitelist of UI keywords) which missed entire categories like games,
/// CLIs, APIs, etc.
const NON_USER_FACING_KEYWORDS: &[&str] = &[
    "refactor",
    "ci",
    "pipeline",
    "migration",
    "schema",
    "infrastructure",
    "devops",
    "dockerfile",
    "linter",
    "formatter",
    "dependency",
    "upgrade",
    "internal",
    "scaffolding",
    "boilerplate",
    "config",
    "tooling",
];

/// Returns true if the task is user-facing (should get UAT).
/// Default: true. Only returns false for clearly internal/infra tasks.
pub fn is_user_facing(title: &str, description: &str) -> bool {
    let text = format!("{} {}", title.to_lowercase(), description.to_lowercase());
    !NON_USER_FACING_KEYWORDS
        .iter()
        .any(|kw| contains_word(&text, kw))
}

/// Check if `text` contains `word` as a whole word (bounded by non-alphanumeric or string edges).
fn contains_word(text: &str, word: &str) -> bool {
    for (i, _) in text.match_indices(word) {
        let before_ok = i == 0 || !text.as_bytes()[i - 1].is_ascii_alphanumeric();
        let after = i + word.len();
        let after_ok = after >= text.len() || !text.as_bytes()[after].is_ascii_alphanumeric();
        if before_ok && after_ok {
            return true;
        }
    }
    false
}

/// Generate human-testable acceptance criteria from task title and existing criteria.
pub fn generate_uat_criteria(title: &str, acceptance_criteria: &[String]) -> Vec<String> {
    let title_lower = title.to_lowercase();
    let mut criteria = Vec::new();

    // Keyword-driven human-testable criteria (word-boundary matching)
    if contains_word(&title_lower, "navigation") || contains_word(&title_lower, "menu") {
        criteria.push("Can reach target in 3 clicks or fewer".to_string());
    }
    if contains_word(&title_lower, "button") || contains_word(&title_lower, "form") {
        criteria.push("Interactive elements respond within 200ms".to_string());
    }
    if contains_word(&title_lower, "layout") || contains_word(&title_lower, "responsive") {
        criteria.push("Layout correct at 1920x1080 and 1366x768".to_string());
    }
    if contains_word(&title_lower, "terminal") {
        criteria.push("Terminal output readable with no rendering glitches".to_string());
    }
    if contains_word(&title_lower, "accessibility") {
        criteria.push("All interactive elements are keyboard-navigable".to_string());
    }
    if contains_word(&title_lower, "animation") {
        criteria.push("Animations are smooth with no visual jank".to_string());
    }

    // Generic fallback if no specific criteria matched
    if criteria.is_empty() {
        criteria.push("Feature works as expected from user perspective".to_string());
    }

    // Append non-technical original criteria prefixed with "Verify: "
    for ac in acceptance_criteria {
        let lower = ac.to_lowercase();
        // Skip purely technical criteria
        let is_technical = lower.contains("compile")
            || lower.contains("tests pass")
            || lower.contains("test pass")
            || lower.contains("coverage")
            || lower.contains("lint")
            || lower.contains("no error");
        if !is_technical {
            criteria.push(format!("Verify: {ac}"));
        }
    }

    criteria
}

/// Classify a task's type from its title and description using keyword heuristics.
pub fn classify_task_type(title: &str, description: &str) -> Option<String> {
    let text = format!("{} {}", title.to_lowercase(), description.to_lowercase());

    if text.contains("design")
        || text.contains("architect")
        || text.contains("plan")
        || text.contains("schema")
        || text.contains("strategy")
    {
        return Some("design".into());
    }

    if text.contains("review")
        || text.contains("audit")
        || text.contains("analyze")
        || text.contains("evaluate")
        || text.contains("inspect")
    {
        return Some("review".into());
    }

    if text.contains("test")
        || text.contains("spec")
        || text.contains("coverage")
        || text.contains("assert")
    {
        return Some("test".into());
    }

    if text.contains("document")
        || text.contains("readme")
        || text.contains("docs")
        || text.contains("api doc")
        || text.contains("comment")
    {
        return Some("document".into());
    }

    if text.contains("implement")
        || text.contains("build")
        || text.contains("create")
        || text.contains("add")
        || text.contains("fix")
        || text.contains("refactor")
        || text.contains("code")
        || text.contains("develop")
    {
        return Some("implement".into());
    }

    None
}

impl ForgeBrain for RuleBasedBrain {
    fn decompose_plan(
        &self,
        spec: &str,
        _available_tools: &[AgentType],
        start_id: u32,
    ) -> anyhow::Result<Vec<Task>> {
        // Check if codebase inventory is present
        let inventory_files = extract_inventory_files(spec);

        // Simple heuristic: split spec by markdown headers into tasks
        let mut tasks = Vec::new();
        let mut task_num = start_id;

        for line in spec.lines() {
            if let Some(header) = line.strip_prefix("## ") {
                let title = header.trim();

                // Skip inventory section headers
                if title == "Source Files" || title == "Test Files" {
                    continue;
                }

                // If we have an inventory, check if this feature already exists
                if !inventory_files.is_empty() {
                    let title_lower = title.to_lowercase().replace([' ', '-'], "_");
                    let already_exists = inventory_files.iter().any(|f| {
                        let f_lower = f.to_lowercase();
                        // Check if any source file name matches the heading
                        f_lower.contains(&title_lower)
                            || title_lower
                                .split('_')
                                .any(|word| word.len() > 3 && f_lower.contains(word))
                    });
                    if already_exists {
                        // Create a review task instead of implement
                        let id = format!("T-{task_num:03}");
                        let desc = format!("Review existing implementation of: {title}");
                        let mut task = Task::new(&id, title, &desc);
                        task.task_type = Some("review".into());
                        tasks.push(task);
                        task_num += 1;
                        continue;
                    }
                }

                let id = format!("T-{task_num:03}");
                let desc = format!("Implement: {title}");
                let mut task = Task::new(&id, title, &desc);
                task.task_type = classify_task_type(title, &desc);
                tasks.push(task);
                task_num += 1;
            }
        }

        // If no headers found, create a single task
        if tasks.is_empty() {
            tasks.push(Task::new(
                format!("T-{start_id:03}"),
                "Implement specification",
                spec.chars().take(500).collect::<String>(),
            ));
        }

        Ok(tasks)
    }

    fn assign_task(&self, task: &Task, available_tools: &[AgentType]) -> anyhow::Result<AgentType> {
        if available_tools.is_empty() {
            return Ok(AgentType::Any);
        }

        let title_lower = task.title.to_lowercase();
        let desc_lower = task.description.to_lowercase();
        let text = format!("{title_lower} {desc_lower}");

        // Keyword-based assignment heuristics (check title + description)
        if text.contains("architect")
            || text.contains("design")
            || text.contains("plan")
            || text.contains("review")
            || text.contains("evaluate")
            || text.contains("decide")
            || text.contains("strategy")
        {
            // Architecture/strategy tasks → Claude (strongest reasoning)
            if available_tools.contains(&AgentType::Claude) {
                return Ok(AgentType::Claude);
            }
        }

        if text.contains("implement")
            || text.contains("code")
            || text.contains("build")
            || text.contains("refactor")
            || text.contains("create")
            || text.contains("add")
            || text.contains("fix")
            || text.contains("develop")
            || text.contains("write code")
        {
            // Implementation tasks → Codex (fast code generation)
            if available_tools.contains(&AgentType::Codex) {
                return Ok(AgentType::Codex);
            }
        }

        if text.contains("test")
            || text.contains("doc")
            || text.contains("document")
            || text.contains("documentation")
            || text.contains("report")
            || text.contains("summary")
            || text.contains("validate")
            || text.contains("verify")
            || text.contains("quality")
            || text.contains("coverage")
        {
            // Testing/docs/validation → Gemini (good at structured output)
            if available_tools.contains(&AgentType::Gemini) {
                return Ok(AgentType::Gemini);
            }
        }

        // Round-robin fallback: distribute by task ID number
        let task_num: usize = task.id.trim_start_matches("T-").parse().unwrap_or(0);
        let idx = task_num % available_tools.len();
        Ok(available_tools[idx].clone())
    }

    fn evaluate_drift(&self, _work_summary: &str, _vision: &str) -> anyhow::Result<DriftScore> {
        // Rule-based brain can't evaluate drift without LLM
        // Return a neutral score
        Ok(DriftScore {
            score: 0.0,
            explanation: "Drift evaluation requires an LLM brain. Set brain to claude or gemini for intelligent drift detection.".into(),
        })
    }

    fn route_knowledge(&self, content: &str) -> anyhow::Result<KnowledgeCategory> {
        let lower = content.to_lowercase();

        // Keyword-based classification
        if lower.contains("research")
            || lower.contains("finding")
            || lower.contains("discovered")
            || lower.contains("learned that")
        {
            return Ok(KnowledgeCategory::Research);
        }

        if lower.contains("decided")
            || lower.contains("decision")
            || lower.contains("chose")
            || lower.contains("adr")
        {
            return Ok(KnowledgeCategory::Decision);
        }

        if lower.contains("lesson")
            || lower.contains("mistake")
            || lower.contains("bug")
            || lower.contains("fix")
        {
            return Ok(KnowledgeCategory::Learning);
        }

        if lower.contains("pattern")
            || lower.contains("convention")
            || lower.contains("best practice")
        {
            return Ok(KnowledgeCategory::Pattern);
        }

        Ok(KnowledgeCategory::Unknown)
    }
}

/// Extract file paths from codebase inventory section if present.
fn extract_inventory_files(spec: &str) -> Vec<String> {
    let marker = "EXISTING CODEBASE INVENTORY:";
    let Some(idx) = spec.find(marker) else {
        return Vec::new();
    };
    let inventory_section = &spec[idx..];
    inventory_section
        .lines()
        .filter_map(|line| {
            let trimmed = line.trim().strip_prefix("- ")?;
            // Lines like "src/foo.rs (42 lines)" — extract the path part
            let path = trimmed.split(' ').next()?;
            if path.contains('.') {
                Some(path.to_string())
            } else {
                None
            }
        })
        .collect()
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_assign_architecture_to_claude() {
        let brain = RuleBasedBrain;
        let task = Task::new("T-001", "Design the API architecture", "...");
        let tools = vec![AgentType::Claude, AgentType::Codex];
        let result = brain.assign_task(&task, &tools).unwrap();
        assert_eq!(result, AgentType::Claude);
    }

    #[test]
    fn test_assign_implementation_to_codex() {
        let brain = RuleBasedBrain;
        let task = Task::new("T-002", "Implement the login endpoint", "...");
        let tools = vec![AgentType::Claude, AgentType::Codex];
        let result = brain.assign_task(&task, &tools).unwrap();
        assert_eq!(result, AgentType::Codex);
    }

    #[test]
    fn test_route_knowledge_research() {
        let brain = RuleBasedBrain;
        let result = brain
            .route_knowledge("Research finding: Codex CLI supports MCP server mode")
            .unwrap();
        assert_eq!(result, KnowledgeCategory::Research);
    }

    #[test]
    fn test_route_knowledge_decision() {
        let brain = RuleBasedBrain;
        let result = brain
            .route_knowledge("We decided to use Rust for the orchestrator")
            .unwrap();
        assert_eq!(result, KnowledgeCategory::Decision);
    }

    #[test]
    fn test_assign_testing_to_gemini() {
        let brain = RuleBasedBrain;
        let task = Task::new("T-003", "Write unit tests for auth module", "...");
        let tools = vec![AgentType::Claude, AgentType::Codex, AgentType::Gemini];
        let result = brain.assign_task(&task, &tools).unwrap();
        assert_eq!(result, AgentType::Gemini);
    }

    #[test]
    fn test_assign_docs_to_gemini() {
        let brain = RuleBasedBrain;
        let task = Task::new("T-004", "API documentation update", "Update the API docs");
        let tools = vec![AgentType::Claude, AgentType::Codex, AgentType::Gemini];
        let result = brain.assign_task(&task, &tools).unwrap();
        assert_eq!(result, AgentType::Gemini);
    }

    #[test]
    fn test_fallback_round_robin() {
        let brain = RuleBasedBrain;
        // "Setup" doesn't match any keyword heuristic — falls through to round-robin
        let task1 = Task::new("T-003", "Setup environment", "Configure dev setup");
        let task2 = Task::new("T-004", "Setup environment", "Configure dev setup");
        let tools = vec![AgentType::Claude, AgentType::Codex, AgentType::Gemini];
        let r1 = brain.assign_task(&task1, &tools).unwrap(); // 3 % 3 = 0 → Claude
        let r2 = brain.assign_task(&task2, &tools).unwrap(); // 4 % 3 = 1 → Codex
        assert_eq!(r1, AgentType::Claude);
        assert_eq!(r2, AgentType::Codex);
    }

    #[test]
    fn test_decompose_plan_from_headers() {
        let brain = RuleBasedBrain;
        let spec = "# My Project\n## Authentication\n## Database\n## API endpoints\n";
        let tasks = brain.decompose_plan(spec, &[AgentType::Claude], 1).unwrap();
        assert_eq!(tasks.len(), 3);
        assert_eq!(tasks[0].title, "Authentication");
        assert_eq!(tasks[1].title, "Database");
    }

    #[test]
    fn test_decompose_plan_with_start_id_offset() {
        let brain = RuleBasedBrain;
        let spec = "## Caching\n## Monitoring\n";
        let tasks = brain.decompose_plan(spec, &[AgentType::Claude], 5).unwrap();
        assert_eq!(tasks.len(), 2);
        assert_eq!(tasks[0].id, "T-005");
        assert_eq!(tasks[1].id, "T-006");
    }

    #[test]
    fn test_decompose_plan_fallback_uses_start_id() {
        let brain = RuleBasedBrain;
        // No ## headers → single fallback task
        let spec = "Just a plain spec with no headers.";
        let tasks = brain
            .decompose_plan(spec, &[AgentType::Claude], 10)
            .unwrap();
        assert_eq!(tasks.len(), 1);
        assert_eq!(tasks[0].id, "T-010");
    }

    #[test]
    fn test_is_user_facing_positive() {
        assert!(is_user_facing(
            "Add dashboard sidebar",
            "Create navigation component"
        ));
        assert!(is_user_facing("Fix button styles", "Update CSS"));
        assert!(is_user_facing(
            "Terminal improvements",
            "Improve terminal output"
        ));
        assert!(is_user_facing("Create login form", "Authentication form"));
        assert!(is_user_facing(
            "Layout restructure",
            "Update the page layout"
        ));
    }

    #[test]
    fn test_is_user_facing_negative() {
        // Only clearly internal/infra tasks are non-user-facing
        assert!(!is_user_facing(
            "Refactor auth module",
            "Clean up internal code"
        ));
        assert!(!is_user_facing("Update CI pipeline", "Fix GitHub Actions"));
        assert!(!is_user_facing(
            "Dockerfile optimization",
            "Reduce image size"
        ));
        assert!(!is_user_facing(
            "Dependency upgrade",
            "Bump all packages to latest"
        ));
        assert!(!is_user_facing(
            "Database migration",
            "Add new schema columns"
        ));
    }

    #[test]
    fn test_is_user_facing_games_and_features() {
        // The old heuristic missed entire categories. Games, CLIs, APIs
        // are all user-facing and must get UAT tasks.
        assert!(is_user_facing(
            "Design High Score Feature",
            "Add high score tracking"
        ));
        assert!(is_user_facing(
            "Implement Combo Multiplier",
            "Combo system for scoring"
        ));
        assert!(is_user_facing(
            "Add caching layer",
            "Redis integration for faster responses"
        ));
        assert!(is_user_facing(
            "Optimize database queries",
            "Improve SQL performance"
        ));
    }

    #[test]
    fn test_uat_criteria_skips_technical() {
        let criteria = generate_uat_criteria(
            "Add navigation menu",
            &[
                "Menu items are visible".to_string(),
                "All tests pass".to_string(), // technical → skip
                "Code compiles without errors".to_string(), // technical → skip
                "Links work correctly".to_string(),
            ],
        );

        // Should have: "Can reach target in 3 clicks" + "Verify: Menu items are visible" + "Verify: Links work correctly"
        assert!(criteria.iter().any(|c| c.contains("3 clicks")));
        assert!(criteria.iter().any(|c| c.starts_with("Verify: Menu items")));
        assert!(criteria.iter().any(|c| c.starts_with("Verify: Links work")));
        // Should NOT have technical criteria
        assert!(!criteria.iter().any(|c| c.contains("tests pass")));
        assert!(!criteria.iter().any(|c| c.contains("compiles")));
    }
}