intent_engine/

tasks.rs

use crate::db::models::{
    CurrentTaskInfo, DoneTaskResponse, Event, EventsSummary, NextStepSuggestion, ParentTaskInfo,
    PickNextResponse, PreviousTaskInfo, SpawnSubtaskResponse, SubtaskInfo, SwitchTaskResponse,
    Task, TaskContext, TaskSearchResult, TaskWithEvents, WorkspaceStatus,
};
use crate::error::{IntentError, Result};
use chrono::Utc;
use sqlx::{Row, SqlitePool};

pub struct TaskManager<'a> {
    pool: &'a SqlitePool,
}

impl<'a> TaskManager<'a> {
    pub fn new(pool: &'a SqlitePool) -> Self {
        Self { pool }
    }

    /// Add a new task
    pub async fn add_task(
        &self,
        name: &str,
        spec: Option<&str>,
        parent_id: Option<i64>,
    ) -> Result<Task> {
        // Check for circular dependency if parent_id is provided
        if let Some(pid) = parent_id {
            self.check_task_exists(pid).await?;
        }

        let now = Utc::now();

        let result = sqlx::query(
            r#"
            INSERT INTO tasks (name, spec, parent_id, status, first_todo_at)
            VALUES (?, ?, ?, 'todo', ?)
            "#,
        )
        .bind(name)
        .bind(spec)
        .bind(parent_id)
        .bind(now)
        .execute(self.pool)
        .await?;

        let id = result.last_insert_rowid();
        self.get_task(id).await
    }

    /// Get a task by ID
    pub async fn get_task(&self, id: i64) -> Result<Task> {
        let task = sqlx::query_as::<_, Task>(
            r#"
            SELECT id, parent_id, name, spec, status, complexity, priority, first_todo_at, first_doing_at, first_done_at
            FROM tasks
            WHERE id = ?
            "#,
        )
        .bind(id)
        .fetch_optional(self.pool)
        .await?
        .ok_or(IntentError::TaskNotFound(id))?;

        Ok(task)
    }

    /// Get a task with events summary
    pub async fn get_task_with_events(&self, id: i64) -> Result<TaskWithEvents> {
        let task = self.get_task(id).await?;
        let events_summary = self.get_events_summary(id).await?;

        Ok(TaskWithEvents {
            task,
            events_summary: Some(events_summary),
        })
    }

    /// Get task context - the complete family tree of a task
    ///
    /// Returns:
    /// - task: The requested task
    /// - ancestors: Parent chain up to root (ordered from immediate parent to root)
    /// - siblings: Other tasks at the same level (same parent_id)
    /// - children: Direct subtasks of this task
    pub async fn get_task_context(&self, id: i64) -> Result<TaskContext> {
        // Get the main task
        let task = self.get_task(id).await?;

        // Get ancestors (walk up parent chain)
        let mut ancestors = Vec::new();
        let mut current_parent_id = task.parent_id;

        while let Some(parent_id) = current_parent_id {
            let parent = self.get_task(parent_id).await?;
            current_parent_id = parent.parent_id;
            ancestors.push(parent);
        }

        // Get siblings (tasks with same parent_id)
        let siblings = if let Some(parent_id) = task.parent_id {
            sqlx::query_as::<_, Task>(
                r#"
                SELECT id, parent_id, name, spec, status, complexity, priority,
                       first_todo_at, first_doing_at, first_done_at
                FROM tasks
                WHERE parent_id = ? AND id != ?
                ORDER BY priority ASC NULLS LAST, id ASC
                "#,
            )
            .bind(parent_id)
            .bind(id)
            .fetch_all(self.pool)
            .await?
        } else {
            // For root tasks, get other root tasks as siblings
            sqlx::query_as::<_, Task>(
                r#"
                SELECT id, parent_id, name, spec, status, complexity, priority,
                       first_todo_at, first_doing_at, first_done_at
                FROM tasks
                WHERE parent_id IS NULL AND id != ?
                ORDER BY priority ASC NULLS LAST, id ASC
                "#,
            )
            .bind(id)
            .fetch_all(self.pool)
            .await?
        };

        // Get children (direct subtasks)
        let children = sqlx::query_as::<_, Task>(
            r#"
            SELECT id, parent_id, name, spec, status, complexity, priority,
                   first_todo_at, first_doing_at, first_done_at
            FROM tasks
            WHERE parent_id = ?
            ORDER BY priority ASC NULLS LAST, id ASC
            "#,
        )
        .bind(id)
        .fetch_all(self.pool)
        .await?;

        // Get blocking tasks (tasks that this task depends on)
        let blocking_tasks = sqlx::query_as::<_, Task>(
            r#"
            SELECT t.id, t.parent_id, t.name, t.spec, t.status, t.complexity, t.priority,
                   t.first_todo_at, t.first_doing_at, t.first_done_at
            FROM tasks t
            JOIN dependencies d ON t.id = d.blocking_task_id
            WHERE d.blocked_task_id = ?
            ORDER BY t.priority ASC NULLS LAST, t.id ASC
            "#,
        )
        .bind(id)
        .fetch_all(self.pool)
        .await?;

        // Get blocked_by tasks (tasks that depend on this task)
        let blocked_by_tasks = sqlx::query_as::<_, Task>(
            r#"
            SELECT t.id, t.parent_id, t.name, t.spec, t.status, t.complexity, t.priority,
                   t.first_todo_at, t.first_doing_at, t.first_done_at
            FROM tasks t
            JOIN dependencies d ON t.id = d.blocked_task_id
            WHERE d.blocking_task_id = ?
            ORDER BY t.priority ASC NULLS LAST, t.id ASC
            "#,
        )
        .bind(id)
        .fetch_all(self.pool)
        .await?;

        Ok(TaskContext {
            task,
            ancestors,
            siblings,
            children,
            dependencies: crate::db::models::TaskDependencies {
                blocking_tasks,
                blocked_by_tasks,
            },
        })
    }

    /// Get events summary for a task
    async fn get_events_summary(&self, task_id: i64) -> Result<EventsSummary> {
        let total_count: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM events WHERE task_id = ?")
            .bind(task_id)
            .fetch_one(self.pool)
            .await?;

        let recent_events = sqlx::query_as::<_, Event>(
            r#"
            SELECT id, task_id, timestamp, log_type, discussion_data
            FROM events
            WHERE task_id = ?
            ORDER BY timestamp DESC
            LIMIT 10
            "#,
        )
        .bind(task_id)
        .fetch_all(self.pool)
        .await?;

        Ok(EventsSummary {
            total_count,
            recent_events,
        })
    }

    /// Update a task
    #[allow(clippy::too_many_arguments)]
    pub async fn update_task(
        &self,
        id: i64,
        name: Option<&str>,
        spec: Option<&str>,
        parent_id: Option<Option<i64>>,
        status: Option<&str>,
        complexity: Option<i32>,
        priority: Option<i32>,
    ) -> Result<Task> {
        // Check task exists
        let task = self.get_task(id).await?;

        // Validate status if provided
        if let Some(s) = status {
            if !["todo", "doing", "done"].contains(&s) {
                return Err(IntentError::InvalidInput(format!("Invalid status: {}", s)));
            }
        }

        // Check for circular dependency if parent_id is being changed
        if let Some(Some(pid)) = parent_id {
            if pid == id {
                return Err(IntentError::CircularDependency {
                    blocking_task_id: pid,
                    blocked_task_id: id,
                });
            }
            self.check_task_exists(pid).await?;
            self.check_circular_dependency(id, pid).await?;
        }

        // Build dynamic update query
        let mut query = String::from("UPDATE tasks SET ");
        let mut updates = Vec::new();

        if let Some(n) = name {
            updates.push(format!("name = '{}'", n.replace('\'', "''")));
        }

        if let Some(s) = spec {
            updates.push(format!("spec = '{}'", s.replace('\'', "''")));
        }

        if let Some(pid) = parent_id {
            match pid {
                Some(p) => updates.push(format!("parent_id = {}", p)),
                None => updates.push("parent_id = NULL".to_string()),
            }
        }

        if let Some(c) = complexity {
            updates.push(format!("complexity = {}", c));
        }

        if let Some(p) = priority {
            updates.push(format!("priority = {}", p));
        }

        if let Some(s) = status {
            updates.push(format!("status = '{}'", s));

            // Update timestamp fields based on status
            let now = Utc::now();
            match s {
                "todo" if task.first_todo_at.is_none() => {
                    updates.push(format!("first_todo_at = '{}'", now.to_rfc3339()));
                },
                "doing" if task.first_doing_at.is_none() => {
                    updates.push(format!("first_doing_at = '{}'", now.to_rfc3339()));
                },
                "done" if task.first_done_at.is_none() => {
                    updates.push(format!("first_done_at = '{}'", now.to_rfc3339()));
                },
                _ => {},
            }
        }

        if updates.is_empty() {
            return Ok(task);
        }

        query.push_str(&updates.join(", "));
        query.push_str(&format!(" WHERE id = {}", id));

        sqlx::query(&query).execute(self.pool).await?;

        self.get_task(id).await
    }

    /// Delete a task
    pub async fn delete_task(&self, id: i64) -> Result<()> {
        self.check_task_exists(id).await?;

        sqlx::query("DELETE FROM tasks WHERE id = ?")
            .bind(id)
            .execute(self.pool)
            .await?;

        Ok(())
    }

    /// Find tasks with optional filters
    pub async fn find_tasks(
        &self,
        status: Option<&str>,
        parent_id: Option<Option<i64>>,
    ) -> Result<Vec<Task>> {
        let mut query = String::from(
            "SELECT id, parent_id, name, NULL as spec, status, complexity, priority, first_todo_at, first_doing_at, first_done_at FROM tasks WHERE 1=1"
        );
        let mut conditions = Vec::new();

        if let Some(s) = status {
            query.push_str(" AND status = ?");
            conditions.push(s.to_string());
        }

        if let Some(pid) = parent_id {
            if let Some(p) = pid {
                query.push_str(" AND parent_id = ?");
                conditions.push(p.to_string());
            } else {
                query.push_str(" AND parent_id IS NULL");
            }
        }

        query.push_str(" ORDER BY id");

        let mut q = sqlx::query_as::<_, Task>(&query);
        for cond in conditions {
            q = q.bind(cond);
        }

        let tasks = q.fetch_all(self.pool).await?;
        Ok(tasks)
    }

    /// Search tasks using full-text search (FTS5)
    /// Returns tasks with match snippets showing highlighted keywords
    pub async fn search_tasks(&self, query: &str) -> Result<Vec<TaskSearchResult>> {
        // Escape special FTS5 characters in the query
        let escaped_query = self.escape_fts_query(query);

        // Use FTS5 to search and get snippets
        // snippet(table, column, start_mark, end_mark, ellipsis, max_tokens)
        // We search in both name (column 0) and spec (column 1)
        let results = sqlx::query(
            r#"
            SELECT
                t.id,
                t.parent_id,
                t.name,
                t.spec,
                t.status,
                t.complexity,
                t.priority,
                t.first_todo_at,
                t.first_doing_at,
                t.first_done_at,
                COALESCE(
                    snippet(tasks_fts, 1, '**', '**', '...', 15),
                    snippet(tasks_fts, 0, '**', '**', '...', 15)
                ) as match_snippet
            FROM tasks_fts
            INNER JOIN tasks t ON tasks_fts.rowid = t.id
            WHERE tasks_fts MATCH ?
            ORDER BY rank
            "#,
        )
        .bind(&escaped_query)
        .fetch_all(self.pool)
        .await?;

        let mut search_results = Vec::new();
        for row in results {
            let task = Task {
                id: row.get("id"),
                parent_id: row.get("parent_id"),
                name: row.get("name"),
                spec: row.get("spec"),
                status: row.get("status"),
                complexity: row.get("complexity"),
                priority: row.get("priority"),
                first_todo_at: row.get("first_todo_at"),
                first_doing_at: row.get("first_doing_at"),
                first_done_at: row.get("first_done_at"),
            };
            let match_snippet: String = row.get("match_snippet");

            search_results.push(TaskSearchResult {
                task,
                match_snippet,
            });
        }

        Ok(search_results)
    }

    /// Escape FTS5 special characters in query
    fn escape_fts_query(&self, query: &str) -> String {
        // FTS5 queries are passed through as-is to support advanced syntax
        // Users can use operators like AND, OR, NOT, *, "phrase search", etc.
        // We only need to handle basic escaping for quotes
        query.replace('"', "\"\"")
    }

    /// Start a task (atomic: update status + set current)
    pub async fn start_task(&self, id: i64, with_events: bool) -> Result<TaskWithEvents> {
        // Check if task is blocked by incomplete dependencies
        use crate::dependencies::get_incomplete_blocking_tasks;
        if let Some(blocking_tasks) = get_incomplete_blocking_tasks(self.pool, id).await? {
            return Err(IntentError::TaskBlocked {
                task_id: id,
                blocking_task_ids: blocking_tasks,
            });
        }

        let mut tx = self.pool.begin().await?;

        let now = Utc::now();

        // Update task status to doing
        sqlx::query(
            r#"
            UPDATE tasks
            SET status = 'doing', first_doing_at = COALESCE(first_doing_at, ?)
            WHERE id = ?
            "#,
        )
        .bind(now)
        .bind(id)
        .execute(&mut *tx)
        .await?;

        // Set as current task
        sqlx::query(
            r#"
            INSERT OR REPLACE INTO workspace_state (key, value)
            VALUES ('current_task_id', ?)
            "#,
        )
        .bind(id.to_string())
        .execute(&mut *tx)
        .await?;

        tx.commit().await?;

        if with_events {
            self.get_task_with_events(id).await
        } else {
            let task = self.get_task(id).await?;
            Ok(TaskWithEvents {
                task,
                events_summary: None,
            })
        }
    }

    /// Complete the current focused task (atomic: check children + update status + clear current)
    /// This command only operates on the current_task_id.
    /// Prerequisites: A task must be set as current
    pub async fn done_task(&self) -> Result<DoneTaskResponse> {
        let mut tx = self.pool.begin().await?;

        // Get the current task ID
        let current_task_id: Option<String> =
            sqlx::query_scalar("SELECT value FROM workspace_state WHERE key = 'current_task_id'")
                .fetch_optional(&mut *tx)
                .await?;

        let id = current_task_id.and_then(|s| s.parse::<i64>().ok()).ok_or(
            IntentError::InvalidInput(
                "No current task is set. Use 'current --set <ID>' to set a task first.".to_string(),
            ),
        )?;

        // Get the task info before completing it
        let task_info: (String, Option<i64>) =
            sqlx::query_as("SELECT name, parent_id FROM tasks WHERE id = ?")
                .bind(id)
                .fetch_one(&mut *tx)
                .await?;
        let (task_name, parent_id) = task_info;

        // Check if all children are done
        let uncompleted_children: i64 = sqlx::query_scalar(
            "SELECT COUNT(*) FROM tasks WHERE parent_id = ? AND status != 'done'",
        )
        .bind(id)
        .fetch_one(&mut *tx)
        .await?;

        if uncompleted_children > 0 {
            return Err(IntentError::UncompletedChildren);
        }

        let now = Utc::now();

        // Update task status to done
        sqlx::query(
            r#"
            UPDATE tasks
            SET status = 'done', first_done_at = COALESCE(first_done_at, ?)
            WHERE id = ?
            "#,
        )
        .bind(now)
        .bind(id)
        .execute(&mut *tx)
        .await?;

        // Clear the current task
        sqlx::query("DELETE FROM workspace_state WHERE key = 'current_task_id'")
            .execute(&mut *tx)
            .await?;

        // Determine next step suggestion based on context
        let next_step_suggestion = if let Some(parent_task_id) = parent_id {
            // Task has a parent - check sibling status
            let remaining_siblings: i64 = sqlx::query_scalar(
                "SELECT COUNT(*) FROM tasks WHERE parent_id = ? AND status != 'done' AND id != ?",
            )
            .bind(parent_task_id)
            .bind(id)
            .fetch_one(&mut *tx)
            .await?;

            if remaining_siblings == 0 {
                // All siblings are done - parent is ready
                let parent_name: String = sqlx::query_scalar("SELECT name FROM tasks WHERE id = ?")
                    .bind(parent_task_id)
                    .fetch_one(&mut *tx)
                    .await?;

                NextStepSuggestion::ParentIsReady {
                    message: format!(
                        "All sub-tasks of parent #{} '{}' are now complete. The parent task is ready for your attention.",
                        parent_task_id, parent_name
                    ),
                    parent_task_id,
                    parent_task_name: parent_name,
                }
            } else {
                // Siblings remain
                let parent_name: String = sqlx::query_scalar("SELECT name FROM tasks WHERE id = ?")
                    .bind(parent_task_id)
                    .fetch_one(&mut *tx)
                    .await?;

                NextStepSuggestion::SiblingTasksRemain {
                    message: format!(
                        "Task #{} completed. Parent task #{} '{}' has other sub-tasks remaining.",
                        id, parent_task_id, parent_name
                    ),
                    parent_task_id,
                    parent_task_name: parent_name,
                    remaining_siblings_count: remaining_siblings,
                }
            }
        } else {
            // No parent - check if this was a top-level task with children or standalone
            let child_count: i64 =
                sqlx::query_scalar("SELECT COUNT(*) FROM tasks WHERE parent_id = ?")
                    .bind(id)
                    .fetch_one(&mut *tx)
                    .await?;

            if child_count > 0 {
                // Top-level task with children completed
                NextStepSuggestion::TopLevelTaskCompleted {
                    message: format!(
                        "Top-level task #{} '{}' has been completed. Well done!",
                        id, task_name
                    ),
                    completed_task_id: id,
                    completed_task_name: task_name.clone(),
                }
            } else {
                // Check if workspace is clear
                let remaining_tasks: i64 = sqlx::query_scalar(
                    "SELECT COUNT(*) FROM tasks WHERE status != 'done' AND id != ?",
                )
                .bind(id)
                .fetch_one(&mut *tx)
                .await?;

                if remaining_tasks == 0 {
                    NextStepSuggestion::WorkspaceIsClear {
                        message: format!(
                            "Project complete! Task #{} was the last remaining task. There are no more 'todo' or 'doing' tasks.",
                            id
                        ),
                        completed_task_id: id,
                    }
                } else {
                    NextStepSuggestion::NoParentContext {
                        message: format!("Task #{} '{}' has been completed.", id, task_name),
                        completed_task_id: id,
                        completed_task_name: task_name.clone(),
                    }
                }
            }
        };

        tx.commit().await?;

        let completed_task = self.get_task(id).await?;

        Ok(DoneTaskResponse {
            completed_task,
            workspace_status: WorkspaceStatus {
                current_task_id: None,
            },
            next_step_suggestion,
        })
    }

    /// Check if a task exists
    async fn check_task_exists(&self, id: i64) -> Result<()> {
        let exists: bool = sqlx::query_scalar("SELECT EXISTS(SELECT 1 FROM tasks WHERE id = ?)")
            .bind(id)
            .fetch_one(self.pool)
            .await?;

        if !exists {
            return Err(IntentError::TaskNotFound(id));
        }

        Ok(())
    }

    /// Check for circular dependencies
    async fn check_circular_dependency(&self, task_id: i64, new_parent_id: i64) -> Result<()> {
        let mut current_id = new_parent_id;

        loop {
            if current_id == task_id {
                return Err(IntentError::CircularDependency {
                    blocking_task_id: new_parent_id,
                    blocked_task_id: task_id,
                });
            }

            let parent: Option<i64> =
                sqlx::query_scalar("SELECT parent_id FROM tasks WHERE id = ?")
                    .bind(current_id)
                    .fetch_optional(self.pool)
                    .await?;

            match parent {
                Some(pid) => current_id = pid,
                None => break,
            }
        }

        Ok(())
    }

    /// Switch to a specific task (atomic: update status to doing + set as current)
    /// If the task is not in 'doing' status, it will be transitioned to 'doing'
    /// Returns response with previous task info (if any) and current task info
    pub async fn switch_to_task(&self, id: i64) -> Result<SwitchTaskResponse> {
        // Verify task exists
        self.check_task_exists(id).await?;

        let mut tx = self.pool.begin().await?;
        let now = Utc::now();

        // Get current task info before switching (if any)
        let current_task_id: Option<String> =
            sqlx::query_scalar("SELECT value FROM workspace_state WHERE key = 'current_task_id'")
                .fetch_optional(&mut *tx)
                .await?;

        let previous_task = if let Some(prev_id_str) = current_task_id {
            if let Ok(prev_id) = prev_id_str.parse::<i64>() {
                // Set previous task back to 'todo' if it was 'doing'
                sqlx::query(
                    r#"
                    UPDATE tasks
                    SET status = 'todo'
                    WHERE id = ? AND status = 'doing'
                    "#,
                )
                .bind(prev_id)
                .execute(&mut *tx)
                .await?;

                Some(PreviousTaskInfo {
                    id: prev_id,
                    status: "todo".to_string(),
                })
            } else {
                None
            }
        } else {
            None
        };

        // Update new task to doing status if not already
        sqlx::query(
            r#"
            UPDATE tasks
            SET status = 'doing',
                first_doing_at = COALESCE(first_doing_at, ?)
            WHERE id = ? AND status != 'doing'
            "#,
        )
        .bind(now)
        .bind(id)
        .execute(&mut *tx)
        .await?;

        // Get new task name for response
        let (task_name, task_status): (String, String) =
            sqlx::query_as("SELECT name, status FROM tasks WHERE id = ?")
                .bind(id)
                .fetch_one(&mut *tx)
                .await?;

        // Set as current task
        sqlx::query(
            r#"
            INSERT OR REPLACE INTO workspace_state (key, value)
            VALUES ('current_task_id', ?)
            "#,
        )
        .bind(id.to_string())
        .execute(&mut *tx)
        .await?;

        tx.commit().await?;

        Ok(SwitchTaskResponse {
            previous_task,
            current_task: CurrentTaskInfo {
                id,
                name: task_name,
                status: task_status,
            },
        })
    }

    /// Create a subtask under the current task and switch to it (atomic operation)
    /// Returns error if there is no current task
    /// Returns response with subtask info and parent task info
    pub async fn spawn_subtask(
        &self,
        name: &str,
        spec: Option<&str>,
    ) -> Result<SpawnSubtaskResponse> {
        // Get current task
        let current_task_id: Option<String> =
            sqlx::query_scalar("SELECT value FROM workspace_state WHERE key = 'current_task_id'")
                .fetch_optional(self.pool)
                .await?;

        let parent_id = current_task_id.and_then(|s| s.parse::<i64>().ok()).ok_or(
            IntentError::InvalidInput("No current task to create subtask under".to_string()),
        )?;

        // Get parent task info
        let parent_name: String = sqlx::query_scalar("SELECT name FROM tasks WHERE id = ?")
            .bind(parent_id)
            .fetch_one(self.pool)
            .await?;

        // Create the subtask
        let subtask = self.add_task(name, spec, Some(parent_id)).await?;

        // Switch to the new subtask (sets status to doing and updates current_task_id)
        self.switch_to_task(subtask.id).await?;

        Ok(SpawnSubtaskResponse {
            subtask: SubtaskInfo {
                id: subtask.id,
                name: subtask.name,
                parent_id,
                status: "doing".to_string(),
            },
            parent_task: ParentTaskInfo {
                id: parent_id,
                name: parent_name,
            },
        })
    }

    /// Intelligently pick tasks from 'todo' and transition them to 'doing'
    /// Returns tasks that were successfully transitioned
    ///
    /// # Arguments
    /// * `max_count` - Maximum number of tasks to pick
    /// * `capacity_limit` - Maximum total number of tasks allowed in 'doing' status
    ///
    /// # Logic
    /// 1. Check current 'doing' task count
    /// 2. Calculate available capacity
    /// 3. Select tasks from 'todo' (prioritized by: priority DESC, complexity ASC)
    /// 4. Transition selected tasks to 'doing'
    pub async fn pick_next_tasks(
        &self,
        max_count: usize,
        capacity_limit: usize,
    ) -> Result<Vec<Task>> {
        let mut tx = self.pool.begin().await?;

        // Get current doing count
        let doing_count: i64 =
            sqlx::query_scalar("SELECT COUNT(*) FROM tasks WHERE status = 'doing'")
                .fetch_one(&mut *tx)
                .await?;

        // Calculate available capacity
        let available = capacity_limit.saturating_sub(doing_count as usize);
        if available == 0 {
            return Ok(vec![]);
        }

        let limit = std::cmp::min(max_count, available);

        // Select tasks from todo, prioritizing by priority DESC, complexity ASC
        let todo_tasks = sqlx::query_as::<_, Task>(
            r#"
            SELECT id, parent_id, name, spec, status, complexity, priority, first_todo_at, first_doing_at, first_done_at
            FROM tasks
            WHERE status = 'todo'
            ORDER BY
                COALESCE(priority, 0) DESC,
                COALESCE(complexity, 5) ASC,
                id ASC
            LIMIT ?
            "#,
        )
        .bind(limit as i64)
        .fetch_all(&mut *tx)
        .await?;

        if todo_tasks.is_empty() {
            return Ok(vec![]);
        }

        let now = Utc::now();

        // Transition selected tasks to 'doing'
        for task in &todo_tasks {
            sqlx::query(
                r#"
                UPDATE tasks
                SET status = 'doing',
                    first_doing_at = COALESCE(first_doing_at, ?)
                WHERE id = ?
                "#,
            )
            .bind(now)
            .bind(task.id)
            .execute(&mut *tx)
            .await?;
        }

        tx.commit().await?;

        // Fetch and return updated tasks in the same order
        let task_ids: Vec<i64> = todo_tasks.iter().map(|t| t.id).collect();
        let placeholders = vec!["?"; task_ids.len()].join(",");
        let query = format!(
            "SELECT id, parent_id, name, spec, status, complexity, priority, first_todo_at, first_doing_at, first_done_at
             FROM tasks WHERE id IN ({})
             ORDER BY
                 COALESCE(priority, 0) DESC,
                 COALESCE(complexity, 5) ASC,
                 id ASC",
            placeholders
        );

        let mut q = sqlx::query_as::<_, Task>(&query);
        for id in task_ids {
            q = q.bind(id);
        }

        let updated_tasks = q.fetch_all(self.pool).await?;
        Ok(updated_tasks)
    }

    /// Intelligently recommend the next task to work on based on context-aware priority model.
    ///
    /// Priority logic:
    /// 1. First priority: Subtasks of the current focused task (depth-first)
    /// 2. Second priority: Top-level tasks (breadth-first)
    /// 3. No recommendation: Return appropriate empty state
    ///
    /// This command does NOT modify task status.
    pub async fn pick_next(&self) -> Result<PickNextResponse> {
        // Step 1: Check if there's a current focused task
        let current_task_id: Option<String> =
            sqlx::query_scalar("SELECT value FROM workspace_state WHERE key = 'current_task_id'")
                .fetch_optional(self.pool)
                .await?;

        if let Some(current_id_str) = current_task_id {
            if let Ok(current_id) = current_id_str.parse::<i64>() {
                // First priority: Get todo subtasks of current focused task
                // Exclude tasks blocked by incomplete dependencies
                let subtasks = sqlx::query_as::<_, Task>(
                    r#"
                    SELECT id, parent_id, name, spec, status, complexity, priority,
                           first_todo_at, first_doing_at, first_done_at
                    FROM tasks
                    WHERE parent_id = ? AND status = 'todo'
                      AND NOT EXISTS (
                        SELECT 1 FROM dependencies d
                        JOIN tasks bt ON d.blocking_task_id = bt.id
                        WHERE d.blocked_task_id = tasks.id
                          AND bt.status != 'done'
                      )
                    ORDER BY COALESCE(priority, 999999) ASC, id ASC
                    LIMIT 1
                    "#,
                )
                .bind(current_id)
                .fetch_optional(self.pool)
                .await?;

                if let Some(task) = subtasks {
                    return Ok(PickNextResponse::focused_subtask(task));
                }
            }
        }

        // Step 2: Second priority - get top-level todo tasks
        // Exclude tasks blocked by incomplete dependencies
        let top_level_task = sqlx::query_as::<_, Task>(
            r#"
            SELECT id, parent_id, name, spec, status, complexity, priority,
                   first_todo_at, first_doing_at, first_done_at
            FROM tasks
            WHERE parent_id IS NULL AND status = 'todo'
              AND NOT EXISTS (
                SELECT 1 FROM dependencies d
                JOIN tasks bt ON d.blocking_task_id = bt.id
                WHERE d.blocked_task_id = tasks.id
                  AND bt.status != 'done'
              )
            ORDER BY COALESCE(priority, 999999) ASC, id ASC
            LIMIT 1
            "#,
        )
        .fetch_optional(self.pool)
        .await?;

        if let Some(task) = top_level_task {
            return Ok(PickNextResponse::top_level_task(task));
        }

        // Step 3: No recommendation - determine why
        // Check if there are any tasks at all
        let total_tasks: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM tasks")
            .fetch_one(self.pool)
            .await?;

        if total_tasks == 0 {
            return Ok(PickNextResponse::no_tasks_in_project());
        }

        // Check if all tasks are completed
        let todo_or_doing_count: i64 =
            sqlx::query_scalar("SELECT COUNT(*) FROM tasks WHERE status IN ('todo', 'doing')")
                .fetch_one(self.pool)
                .await?;

        if todo_or_doing_count == 0 {
            return Ok(PickNextResponse::all_tasks_completed());
        }

        // Otherwise, there are tasks but none available based on current context
        Ok(PickNextResponse::no_available_todos())
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::events::EventManager;
    use crate::test_utils::test_helpers::TestContext;

    #[tokio::test]
    async fn test_add_task() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let task = manager.add_task("Test task", None, None).await.unwrap();

        assert_eq!(task.name, "Test task");
        assert_eq!(task.status, "todo");
        assert!(task.first_todo_at.is_some());
        assert!(task.first_doing_at.is_none());
        assert!(task.first_done_at.is_none());
    }

    #[tokio::test]
    async fn test_add_task_with_spec() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let spec = "This is a task specification";
        let task = manager
            .add_task("Test task", Some(spec), None)
            .await
            .unwrap();

        assert_eq!(task.name, "Test task");
        assert_eq!(task.spec.as_deref(), Some(spec));
    }

    #[tokio::test]
    async fn test_add_task_with_parent() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let parent = manager.add_task("Parent task", None, None).await.unwrap();
        let child = manager
            .add_task("Child task", None, Some(parent.id))
            .await
            .unwrap();

        assert_eq!(child.parent_id, Some(parent.id));
    }

    #[tokio::test]
    async fn test_get_task() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let created = manager.add_task("Test task", None, None).await.unwrap();
        let retrieved = manager.get_task(created.id).await.unwrap();

        assert_eq!(created.id, retrieved.id);
        assert_eq!(created.name, retrieved.name);
    }

    #[tokio::test]
    async fn test_get_task_not_found() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let result = manager.get_task(999).await;
        assert!(matches!(result, Err(IntentError::TaskNotFound(999))));
    }

    #[tokio::test]
    async fn test_update_task_name() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let task = manager.add_task("Original name", None, None).await.unwrap();
        let updated = manager
            .update_task(task.id, Some("New name"), None, None, None, None, None)
            .await
            .unwrap();

        assert_eq!(updated.name, "New name");
    }

    #[tokio::test]
    async fn test_update_task_status() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let task = manager.add_task("Test task", None, None).await.unwrap();
        let updated = manager
            .update_task(task.id, None, None, None, Some("doing"), None, None)
            .await
            .unwrap();

        assert_eq!(updated.status, "doing");
        assert!(updated.first_doing_at.is_some());
    }

    #[tokio::test]
    async fn test_delete_task() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let task = manager.add_task("Test task", None, None).await.unwrap();
        manager.delete_task(task.id).await.unwrap();

        let result = manager.get_task(task.id).await;
        assert!(result.is_err());
    }

    #[tokio::test]
    async fn test_find_tasks_by_status() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        manager.add_task("Todo task", None, None).await.unwrap();
        let doing_task = manager.add_task("Doing task", None, None).await.unwrap();
        manager
            .update_task(doing_task.id, None, None, None, Some("doing"), None, None)
            .await
            .unwrap();

        let todo_tasks = manager.find_tasks(Some("todo"), None).await.unwrap();
        let doing_tasks = manager.find_tasks(Some("doing"), None).await.unwrap();

        assert_eq!(todo_tasks.len(), 1);
        assert_eq!(doing_tasks.len(), 1);
        assert_eq!(doing_tasks[0].status, "doing");
    }

    #[tokio::test]
    async fn test_find_tasks_by_parent() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let parent = manager.add_task("Parent", None, None).await.unwrap();
        manager
            .add_task("Child 1", None, Some(parent.id))
            .await
            .unwrap();
        manager
            .add_task("Child 2", None, Some(parent.id))
            .await
            .unwrap();

        let children = manager
            .find_tasks(None, Some(Some(parent.id)))
            .await
            .unwrap();

        assert_eq!(children.len(), 2);
    }

    #[tokio::test]
    async fn test_start_task() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let task = manager.add_task("Test task", None, None).await.unwrap();
        let started = manager.start_task(task.id, false).await.unwrap();

        assert_eq!(started.task.status, "doing");
        assert!(started.task.first_doing_at.is_some());

        // Verify it's set as current task
        let current: Option<String> =
            sqlx::query_scalar("SELECT value FROM workspace_state WHERE key = 'current_task_id'")
                .fetch_optional(ctx.pool())
                .await
                .unwrap();

        assert_eq!(current, Some(task.id.to_string()));
    }

    #[tokio::test]
    async fn test_start_task_with_events() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let task = manager.add_task("Test task", None, None).await.unwrap();

        // Add an event
        sqlx::query("INSERT INTO events (task_id, log_type, discussion_data) VALUES (?, ?, ?)")
            .bind(task.id)
            .bind("test")
            .bind("test event")
            .execute(ctx.pool())
            .await
            .unwrap();

        let started = manager.start_task(task.id, true).await.unwrap();

        assert!(started.events_summary.is_some());
        let summary = started.events_summary.unwrap();
        assert_eq!(summary.total_count, 1);
    }

    #[tokio::test]
    async fn test_done_task() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let task = manager.add_task("Test task", None, None).await.unwrap();
        manager.start_task(task.id, false).await.unwrap();
        let response = manager.done_task().await.unwrap();

        assert_eq!(response.completed_task.status, "done");
        assert!(response.completed_task.first_done_at.is_some());
        assert_eq!(response.workspace_status.current_task_id, None);

        // Should be WORKSPACE_IS_CLEAR since it's the only task
        match response.next_step_suggestion {
            NextStepSuggestion::WorkspaceIsClear { .. } => {},
            _ => panic!("Expected WorkspaceIsClear suggestion"),
        }

        // Verify current task is cleared
        let current: Option<String> =
            sqlx::query_scalar("SELECT value FROM workspace_state WHERE key = 'current_task_id'")
                .fetch_optional(ctx.pool())
                .await
                .unwrap();

        assert!(current.is_none());
    }

    #[tokio::test]
    async fn test_done_task_with_uncompleted_children() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let parent = manager.add_task("Parent", None, None).await.unwrap();
        manager
            .add_task("Child", None, Some(parent.id))
            .await
            .unwrap();

        // Set parent as current task
        manager.start_task(parent.id, false).await.unwrap();

        let result = manager.done_task().await;
        assert!(matches!(result, Err(IntentError::UncompletedChildren)));
    }

    #[tokio::test]
    async fn test_done_task_with_completed_children() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let parent = manager.add_task("Parent", None, None).await.unwrap();
        let child = manager
            .add_task("Child", None, Some(parent.id))
            .await
            .unwrap();

        // Complete child first
        manager.start_task(child.id, false).await.unwrap();
        let child_response = manager.done_task().await.unwrap();

        // Child completion should suggest parent is ready
        match child_response.next_step_suggestion {
            NextStepSuggestion::ParentIsReady { parent_task_id, .. } => {
                assert_eq!(parent_task_id, parent.id);
            },
            _ => panic!("Expected ParentIsReady suggestion"),
        }

        // Now parent can be completed
        manager.start_task(parent.id, false).await.unwrap();
        let parent_response = manager.done_task().await.unwrap();
        assert_eq!(parent_response.completed_task.status, "done");

        // Parent completion should indicate top-level task completed (since it had children)
        match parent_response.next_step_suggestion {
            NextStepSuggestion::TopLevelTaskCompleted { .. } => {},
            _ => panic!("Expected TopLevelTaskCompleted suggestion"),
        }
    }

    #[tokio::test]
    async fn test_circular_dependency() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let task1 = manager.add_task("Task 1", None, None).await.unwrap();
        let task2 = manager
            .add_task("Task 2", None, Some(task1.id))
            .await
            .unwrap();

        // Try to make task1 a child of task2 (circular)
        let result = manager
            .update_task(task1.id, None, None, Some(Some(task2.id)), None, None, None)
            .await;

        assert!(matches!(
            result,
            Err(IntentError::CircularDependency { .. })
        ));
    }

    #[tokio::test]
    async fn test_invalid_parent_id() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let result = manager.add_task("Test", None, Some(999)).await;
        assert!(matches!(result, Err(IntentError::TaskNotFound(999))));
    }

    #[tokio::test]
    async fn test_update_task_complexity_and_priority() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        let task = manager.add_task("Test task", None, None).await.unwrap();
        let updated = manager
            .update_task(task.id, None, None, None, None, Some(8), Some(10))
            .await
            .unwrap();

        assert_eq!(updated.complexity, Some(8));
        assert_eq!(updated.priority, Some(10));
    }

    #[tokio::test]
    async fn test_switch_to_task() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create a task
        let task = manager.add_task("Test task", None, None).await.unwrap();
        assert_eq!(task.status, "todo");

        // Switch to it
        let response = manager.switch_to_task(task.id).await.unwrap();
        assert_eq!(response.current_task.id, task.id);
        assert_eq!(response.current_task.status, "doing");
        assert!(response.previous_task.is_none());

        // Verify it's set as current task
        let current: Option<String> =
            sqlx::query_scalar("SELECT value FROM workspace_state WHERE key = 'current_task_id'")
                .fetch_optional(ctx.pool())
                .await
                .unwrap();

        assert_eq!(current, Some(task.id.to_string()));
    }

    #[tokio::test]
    async fn test_switch_to_task_already_doing() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create and start a task
        let task = manager.add_task("Test task", None, None).await.unwrap();
        manager.start_task(task.id, false).await.unwrap();

        // Switch to it again (should be idempotent)
        let response = manager.switch_to_task(task.id).await.unwrap();
        assert_eq!(response.current_task.id, task.id);
        assert_eq!(response.current_task.status, "doing");
    }

    #[tokio::test]
    async fn test_spawn_subtask() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create and start a parent task
        let parent = manager.add_task("Parent task", None, None).await.unwrap();
        manager.start_task(parent.id, false).await.unwrap();

        // Spawn a subtask
        let response = manager
            .spawn_subtask("Child task", Some("Details"))
            .await
            .unwrap();

        assert_eq!(response.subtask.parent_id, parent.id);
        assert_eq!(response.subtask.name, "Child task");
        assert_eq!(response.subtask.status, "doing");
        assert_eq!(response.parent_task.id, parent.id);
        assert_eq!(response.parent_task.name, "Parent task");

        // Verify subtask is now the current task
        let current: Option<String> =
            sqlx::query_scalar("SELECT value FROM workspace_state WHERE key = 'current_task_id'")
                .fetch_optional(ctx.pool())
                .await
                .unwrap();

        assert_eq!(current, Some(response.subtask.id.to_string()));

        // Verify subtask is in doing status
        let retrieved = manager.get_task(response.subtask.id).await.unwrap();
        assert_eq!(retrieved.status, "doing");
    }

    #[tokio::test]
    async fn test_spawn_subtask_no_current_task() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Try to spawn subtask without a current task
        let result = manager.spawn_subtask("Child", None).await;
        assert!(result.is_err());
    }

    #[tokio::test]
    async fn test_pick_next_tasks_basic() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create 10 todo tasks
        for i in 1..=10 {
            manager
                .add_task(&format!("Task {}", i), None, None)
                .await
                .unwrap();
        }

        // Pick 5 tasks with capacity limit of 5
        let picked = manager.pick_next_tasks(5, 5).await.unwrap();

        assert_eq!(picked.len(), 5);
        for task in &picked {
            assert_eq!(task.status, "doing");
            assert!(task.first_doing_at.is_some());
        }

        // Verify total doing count
        let doing_count: i64 =
            sqlx::query_scalar("SELECT COUNT(*) FROM tasks WHERE status = 'doing'")
                .fetch_one(ctx.pool())
                .await
                .unwrap();

        assert_eq!(doing_count, 5);
    }

    #[tokio::test]
    async fn test_pick_next_tasks_with_existing_doing() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create 10 todo tasks
        for i in 1..=10 {
            manager
                .add_task(&format!("Task {}", i), None, None)
                .await
                .unwrap();
        }

        // Start 2 tasks
        let tasks = manager.find_tasks(Some("todo"), None).await.unwrap();
        manager.start_task(tasks[0].id, false).await.unwrap();
        manager.start_task(tasks[1].id, false).await.unwrap();

        // Pick more tasks with capacity limit of 5
        let picked = manager.pick_next_tasks(10, 5).await.unwrap();

        // Should only pick 3 more (5 - 2 = 3)
        assert_eq!(picked.len(), 3);

        // Verify total doing count
        let doing_count: i64 =
            sqlx::query_scalar("SELECT COUNT(*) FROM tasks WHERE status = 'doing'")
                .fetch_one(ctx.pool())
                .await
                .unwrap();

        assert_eq!(doing_count, 5);
    }

    #[tokio::test]
    async fn test_pick_next_tasks_at_capacity() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create 10 tasks
        for i in 1..=10 {
            manager
                .add_task(&format!("Task {}", i), None, None)
                .await
                .unwrap();
        }

        // Fill capacity
        let first_batch = manager.pick_next_tasks(5, 5).await.unwrap();
        assert_eq!(first_batch.len(), 5);

        // Try to pick more (should return empty)
        let second_batch = manager.pick_next_tasks(5, 5).await.unwrap();
        assert_eq!(second_batch.len(), 0);
    }

    #[tokio::test]
    async fn test_pick_next_tasks_priority_ordering() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create tasks with different priorities
        let low = manager.add_task("Low priority", None, None).await.unwrap();
        manager
            .update_task(low.id, None, None, None, None, None, Some(1))
            .await
            .unwrap();

        let high = manager.add_task("High priority", None, None).await.unwrap();
        manager
            .update_task(high.id, None, None, None, None, None, Some(10))
            .await
            .unwrap();

        let medium = manager
            .add_task("Medium priority", None, None)
            .await
            .unwrap();
        manager
            .update_task(medium.id, None, None, None, None, None, Some(5))
            .await
            .unwrap();

        // Pick tasks
        let picked = manager.pick_next_tasks(3, 5).await.unwrap();

        // Should be ordered by priority DESC
        assert_eq!(picked.len(), 3);
        assert_eq!(picked[0].priority, Some(10)); // high
        assert_eq!(picked[1].priority, Some(5)); // medium
        assert_eq!(picked[2].priority, Some(1)); // low
    }

    #[tokio::test]
    async fn test_pick_next_tasks_complexity_ordering() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create tasks with different complexities (same priority)
        let complex = manager.add_task("Complex", None, None).await.unwrap();
        manager
            .update_task(complex.id, None, None, None, None, Some(9), Some(5))
            .await
            .unwrap();

        let simple = manager.add_task("Simple", None, None).await.unwrap();
        manager
            .update_task(simple.id, None, None, None, None, Some(1), Some(5))
            .await
            .unwrap();

        let medium = manager.add_task("Medium", None, None).await.unwrap();
        manager
            .update_task(medium.id, None, None, None, None, Some(5), Some(5))
            .await
            .unwrap();

        // Pick tasks
        let picked = manager.pick_next_tasks(3, 5).await.unwrap();

        // Should be ordered by complexity ASC (simple first)
        assert_eq!(picked.len(), 3);
        assert_eq!(picked[0].complexity, Some(1)); // simple
        assert_eq!(picked[1].complexity, Some(5)); // medium
        assert_eq!(picked[2].complexity, Some(9)); // complex
    }

    #[tokio::test]
    async fn test_done_task_sibling_tasks_remain() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create parent with multiple children
        let parent = manager.add_task("Parent Task", None, None).await.unwrap();
        let child1 = manager
            .add_task("Child 1", None, Some(parent.id))
            .await
            .unwrap();
        let child2 = manager
            .add_task("Child 2", None, Some(parent.id))
            .await
            .unwrap();
        let _child3 = manager
            .add_task("Child 3", None, Some(parent.id))
            .await
            .unwrap();

        // Complete first child
        manager.start_task(child1.id, false).await.unwrap();
        let response = manager.done_task().await.unwrap();

        // Should indicate siblings remain
        match response.next_step_suggestion {
            NextStepSuggestion::SiblingTasksRemain {
                parent_task_id,
                remaining_siblings_count,
                ..
            } => {
                assert_eq!(parent_task_id, parent.id);
                assert_eq!(remaining_siblings_count, 2); // child2 and child3
            },
            _ => panic!("Expected SiblingTasksRemain suggestion"),
        }

        // Complete second child
        manager.start_task(child2.id, false).await.unwrap();
        let response2 = manager.done_task().await.unwrap();

        // Should still indicate siblings remain
        match response2.next_step_suggestion {
            NextStepSuggestion::SiblingTasksRemain {
                remaining_siblings_count,
                ..
            } => {
                assert_eq!(remaining_siblings_count, 1); // only child3
            },
            _ => panic!("Expected SiblingTasksRemain suggestion"),
        }
    }

    #[tokio::test]
    async fn test_done_task_top_level_with_children() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create top-level task with children
        let parent = manager.add_task("Epic Task", None, None).await.unwrap();
        let child = manager
            .add_task("Sub Task", None, Some(parent.id))
            .await
            .unwrap();

        // Complete child first
        manager.start_task(child.id, false).await.unwrap();
        manager.done_task().await.unwrap();

        // Complete parent
        manager.start_task(parent.id, false).await.unwrap();
        let response = manager.done_task().await.unwrap();

        // Should be TOP_LEVEL_TASK_COMPLETED
        match response.next_step_suggestion {
            NextStepSuggestion::TopLevelTaskCompleted {
                completed_task_id,
                completed_task_name,
                ..
            } => {
                assert_eq!(completed_task_id, parent.id);
                assert_eq!(completed_task_name, "Epic Task");
            },
            _ => panic!("Expected TopLevelTaskCompleted suggestion"),
        }
    }

    #[tokio::test]
    async fn test_done_task_no_parent_context() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create multiple standalone tasks
        let task1 = manager
            .add_task("Standalone Task 1", None, None)
            .await
            .unwrap();
        let _task2 = manager
            .add_task("Standalone Task 2", None, None)
            .await
            .unwrap();

        // Complete first task
        manager.start_task(task1.id, false).await.unwrap();
        let response = manager.done_task().await.unwrap();

        // Should be NO_PARENT_CONTEXT since task2 is still pending
        match response.next_step_suggestion {
            NextStepSuggestion::NoParentContext {
                completed_task_id,
                completed_task_name,
                ..
            } => {
                assert_eq!(completed_task_id, task1.id);
                assert_eq!(completed_task_name, "Standalone Task 1");
            },
            _ => panic!("Expected NoParentContext suggestion"),
        }
    }

    #[tokio::test]
    async fn test_search_tasks_by_name() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create tasks with different names
        manager
            .add_task("Authentication bug fix", Some("Fix login issue"), None)
            .await
            .unwrap();
        manager
            .add_task("Database migration", Some("Migrate to PostgreSQL"), None)
            .await
            .unwrap();
        manager
            .add_task("Authentication feature", Some("Add OAuth2 support"), None)
            .await
            .unwrap();

        // Search for "authentication"
        let results = manager.search_tasks("authentication").await.unwrap();

        assert_eq!(results.len(), 2);
        assert!(results[0]
            .task
            .name
            .to_lowercase()
            .contains("authentication"));
        assert!(results[1]
            .task
            .name
            .to_lowercase()
            .contains("authentication"));

        // Check that match_snippet is present
        assert!(!results[0].match_snippet.is_empty());
    }

    #[tokio::test]
    async fn test_search_tasks_by_spec() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create tasks
        manager
            .add_task("Task 1", Some("Implement JWT authentication"), None)
            .await
            .unwrap();
        manager
            .add_task("Task 2", Some("Add user registration"), None)
            .await
            .unwrap();
        manager
            .add_task("Task 3", Some("JWT token refresh"), None)
            .await
            .unwrap();

        // Search for "JWT"
        let results = manager.search_tasks("JWT").await.unwrap();

        assert_eq!(results.len(), 2);
        for result in &results {
            assert!(result
                .task
                .spec
                .as_ref()
                .unwrap()
                .to_uppercase()
                .contains("JWT"));
        }
    }

    #[tokio::test]
    async fn test_search_tasks_with_advanced_query() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create tasks
        manager
            .add_task("Bug fix", Some("Fix critical authentication bug"), None)
            .await
            .unwrap();
        manager
            .add_task("Feature", Some("Add authentication feature"), None)
            .await
            .unwrap();
        manager
            .add_task("Bug report", Some("Report critical database bug"), None)
            .await
            .unwrap();

        // Search with AND operator
        let results = manager
            .search_tasks("authentication AND bug")
            .await
            .unwrap();

        assert_eq!(results.len(), 1);
        assert!(results[0]
            .task
            .spec
            .as_ref()
            .unwrap()
            .contains("authentication"));
        assert!(results[0].task.spec.as_ref().unwrap().contains("bug"));
    }

    #[tokio::test]
    async fn test_search_tasks_no_results() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create tasks
        manager
            .add_task("Task 1", Some("Some description"), None)
            .await
            .unwrap();

        // Search for non-existent term
        let results = manager.search_tasks("nonexistent").await.unwrap();

        assert_eq!(results.len(), 0);
    }

    #[tokio::test]
    async fn test_search_tasks_snippet_highlighting() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create task with keyword in spec
        manager
            .add_task(
                "Test task",
                Some("This is a description with the keyword authentication in the middle"),
                None,
            )
            .await
            .unwrap();

        // Search for "authentication"
        let results = manager.search_tasks("authentication").await.unwrap();

        assert_eq!(results.len(), 1);
        // Check that snippet contains highlighted keyword (marked with **)
        assert!(results[0].match_snippet.contains("**authentication**"));
    }

    #[tokio::test]
    async fn test_pick_next_focused_subtask() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create parent task and set as current
        let parent = manager.add_task("Parent task", None, None).await.unwrap();
        manager.start_task(parent.id, false).await.unwrap();

        // Create subtasks with different priorities
        let subtask1 = manager
            .add_task("Subtask 1", None, Some(parent.id))
            .await
            .unwrap();
        let subtask2 = manager
            .add_task("Subtask 2", None, Some(parent.id))
            .await
            .unwrap();

        // Set priorities: subtask1 = 2, subtask2 = 1 (lower number = higher priority)
        manager
            .update_task(subtask1.id, None, None, None, None, None, Some(2))
            .await
            .unwrap();
        manager
            .update_task(subtask2.id, None, None, None, None, None, Some(1))
            .await
            .unwrap();

        // Pick next should recommend subtask2 (priority 1)
        let response = manager.pick_next().await.unwrap();

        assert_eq!(response.suggestion_type, "FOCUSED_SUB_TASK");
        assert!(response.task.is_some());
        assert_eq!(response.task.as_ref().unwrap().id, subtask2.id);
        assert_eq!(response.task.as_ref().unwrap().name, "Subtask 2");
    }

    #[tokio::test]
    async fn test_pick_next_top_level_task() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create top-level tasks with different priorities
        let task1 = manager.add_task("Task 1", None, None).await.unwrap();
        let task2 = manager.add_task("Task 2", None, None).await.unwrap();

        // Set priorities: task1 = 5, task2 = 3 (lower number = higher priority)
        manager
            .update_task(task1.id, None, None, None, None, None, Some(5))
            .await
            .unwrap();
        manager
            .update_task(task2.id, None, None, None, None, None, Some(3))
            .await
            .unwrap();

        // Pick next should recommend task2 (priority 3)
        let response = manager.pick_next().await.unwrap();

        assert_eq!(response.suggestion_type, "TOP_LEVEL_TASK");
        assert!(response.task.is_some());
        assert_eq!(response.task.as_ref().unwrap().id, task2.id);
        assert_eq!(response.task.as_ref().unwrap().name, "Task 2");
    }

    #[tokio::test]
    async fn test_pick_next_no_tasks() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // No tasks created
        let response = manager.pick_next().await.unwrap();

        assert_eq!(response.suggestion_type, "NONE");
        assert_eq!(response.reason_code.as_deref(), Some("NO_TASKS_IN_PROJECT"));
        assert!(response.message.is_some());
    }

    #[tokio::test]
    async fn test_pick_next_all_completed() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create task and mark as done
        let task = manager.add_task("Task 1", None, None).await.unwrap();
        manager.start_task(task.id, false).await.unwrap();
        manager.done_task().await.unwrap();

        // Pick next should indicate all tasks completed
        let response = manager.pick_next().await.unwrap();

        assert_eq!(response.suggestion_type, "NONE");
        assert_eq!(response.reason_code.as_deref(), Some("ALL_TASKS_COMPLETED"));
        assert!(response.message.is_some());
    }

    #[tokio::test]
    async fn test_pick_next_no_available_todos() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create a parent task that's in "doing" status
        let parent = manager.add_task("Parent task", None, None).await.unwrap();
        manager.start_task(parent.id, false).await.unwrap();

        // Create a subtask also in "doing" status (no "todo" subtasks)
        let subtask = manager
            .add_task("Subtask", None, Some(parent.id))
            .await
            .unwrap();
        // Switch to subtask (this will set parent back to todo, so we need to manually set subtask to doing)
        sqlx::query("UPDATE tasks SET status = 'doing' WHERE id = ?")
            .bind(subtask.id)
            .execute(ctx.pool())
            .await
            .unwrap();

        // Set subtask as current
        sqlx::query(
            "INSERT OR REPLACE INTO workspace_state (key, value) VALUES ('current_task_id', ?)",
        )
        .bind(subtask.id.to_string())
        .execute(ctx.pool())
        .await
        .unwrap();

        // Set parent to doing (not todo)
        sqlx::query("UPDATE tasks SET status = 'doing' WHERE id = ?")
            .bind(parent.id)
            .execute(ctx.pool())
            .await
            .unwrap();

        // Pick next should indicate no available todos
        let response = manager.pick_next().await.unwrap();

        assert_eq!(response.suggestion_type, "NONE");
        assert_eq!(response.reason_code.as_deref(), Some("NO_AVAILABLE_TODOS"));
        assert!(response.message.is_some());
    }

    #[tokio::test]
    async fn test_pick_next_priority_ordering() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create parent and set as current
        let parent = manager.add_task("Parent", None, None).await.unwrap();
        manager.start_task(parent.id, false).await.unwrap();

        // Create multiple subtasks with various priorities
        let sub1 = manager
            .add_task("Priority 10", None, Some(parent.id))
            .await
            .unwrap();
        manager
            .update_task(sub1.id, None, None, None, None, None, Some(10))
            .await
            .unwrap();

        let sub2 = manager
            .add_task("Priority 1", None, Some(parent.id))
            .await
            .unwrap();
        manager
            .update_task(sub2.id, None, None, None, None, None, Some(1))
            .await
            .unwrap();

        let sub3 = manager
            .add_task("Priority 5", None, Some(parent.id))
            .await
            .unwrap();
        manager
            .update_task(sub3.id, None, None, None, None, None, Some(5))
            .await
            .unwrap();

        // Pick next should recommend the task with priority 1 (lowest number)
        let response = manager.pick_next().await.unwrap();

        assert_eq!(response.suggestion_type, "FOCUSED_SUB_TASK");
        assert_eq!(response.task.as_ref().unwrap().id, sub2.id);
        assert_eq!(response.task.as_ref().unwrap().name, "Priority 1");
    }

    #[tokio::test]
    async fn test_pick_next_falls_back_to_top_level_when_no_subtasks() {
        let ctx = TestContext::new().await;
        let manager = TaskManager::new(ctx.pool());

        // Create parent without subtasks and set as current
        let parent = manager.add_task("Parent", None, None).await.unwrap();
        manager.start_task(parent.id, false).await.unwrap();

        // Create another top-level task
        let top_level = manager
            .add_task("Top level task", None, None)
            .await
            .unwrap();

        // Pick next should fall back to top-level task since parent has no todo subtasks
        let response = manager.pick_next().await.unwrap();

        assert_eq!(response.suggestion_type, "TOP_LEVEL_TASK");
        assert_eq!(response.task.as_ref().unwrap().id, top_level.id);
    }

    // ===== Missing coverage tests =====

    #[tokio::test]
    async fn test_get_task_with_events() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());
        let event_mgr = EventManager::new(ctx.pool());

        let task = task_mgr.add_task("Test", None, None).await.unwrap();

        // Add some events
        event_mgr
            .add_event(task.id, "progress", "Event 1")
            .await
            .unwrap();
        event_mgr
            .add_event(task.id, "decision", "Event 2")
            .await
            .unwrap();

        let result = task_mgr.get_task_with_events(task.id).await.unwrap();

        assert_eq!(result.task.id, task.id);
        assert!(result.events_summary.is_some());

        let summary = result.events_summary.unwrap();
        assert_eq!(summary.total_count, 2);
        assert_eq!(summary.recent_events.len(), 2);
        assert_eq!(summary.recent_events[0].log_type, "decision"); // Most recent first
        assert_eq!(summary.recent_events[1].log_type, "progress");
    }

    #[tokio::test]
    async fn test_get_task_with_events_nonexistent() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());

        let result = task_mgr.get_task_with_events(999).await;
        assert!(matches!(result, Err(IntentError::TaskNotFound(999))));
    }

    #[tokio::test]
    async fn test_get_task_with_many_events() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());
        let event_mgr = EventManager::new(ctx.pool());

        let task = task_mgr.add_task("Test", None, None).await.unwrap();

        // Add 20 events
        for i in 0..20 {
            event_mgr
                .add_event(task.id, "test", &format!("Event {}", i))
                .await
                .unwrap();
        }

        let result = task_mgr.get_task_with_events(task.id).await.unwrap();
        let summary = result.events_summary.unwrap();

        assert_eq!(summary.total_count, 20);
        assert_eq!(summary.recent_events.len(), 10); // Limited to 10
    }

    #[tokio::test]
    async fn test_get_task_with_no_events() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());

        let task = task_mgr.add_task("Test", None, None).await.unwrap();

        let result = task_mgr.get_task_with_events(task.id).await.unwrap();
        let summary = result.events_summary.unwrap();

        assert_eq!(summary.total_count, 0);
        assert_eq!(summary.recent_events.len(), 0);
    }

    #[tokio::test]
    async fn test_pick_next_tasks_zero_capacity() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());

        task_mgr.add_task("Task 1", None, None).await.unwrap();

        // capacity_limit = 0 means no capacity available
        let results = task_mgr.pick_next_tasks(10, 0).await.unwrap();
        assert_eq!(results.len(), 0);
    }

    #[tokio::test]
    async fn test_pick_next_tasks_capacity_exceeds_available() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());

        task_mgr.add_task("Task 1", None, None).await.unwrap();
        task_mgr.add_task("Task 2", None, None).await.unwrap();

        // Request 10 tasks but only 2 available, capacity = 100
        let results = task_mgr.pick_next_tasks(10, 100).await.unwrap();
        assert_eq!(results.len(), 2); // Only returns available tasks
    }

    // ========== task_context tests ==========

    #[tokio::test]
    async fn test_get_task_context_root_task_no_relations() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());

        // Create a single root task with no relations
        let task = task_mgr.add_task("Root task", None, None).await.unwrap();

        let context = task_mgr.get_task_context(task.id).await.unwrap();

        // Verify task itself
        assert_eq!(context.task.id, task.id);
        assert_eq!(context.task.name, "Root task");

        // No ancestors (root task)
        assert_eq!(context.ancestors.len(), 0);

        // No siblings
        assert_eq!(context.siblings.len(), 0);

        // No children
        assert_eq!(context.children.len(), 0);
    }

    #[tokio::test]
    async fn test_get_task_context_with_siblings() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());

        // Create multiple root tasks (siblings)
        let task1 = task_mgr.add_task("Task 1", None, None).await.unwrap();
        let task2 = task_mgr.add_task("Task 2", None, None).await.unwrap();
        let task3 = task_mgr.add_task("Task 3", None, None).await.unwrap();

        let context = task_mgr.get_task_context(task2.id).await.unwrap();

        // Verify task itself
        assert_eq!(context.task.id, task2.id);

        // No ancestors (root task)
        assert_eq!(context.ancestors.len(), 0);

        // Should have 2 siblings
        assert_eq!(context.siblings.len(), 2);
        let sibling_ids: Vec<i64> = context.siblings.iter().map(|t| t.id).collect();
        assert!(sibling_ids.contains(&task1.id));
        assert!(sibling_ids.contains(&task3.id));
        assert!(!sibling_ids.contains(&task2.id)); // Should not include itself

        // No children
        assert_eq!(context.children.len(), 0);
    }

    #[tokio::test]
    async fn test_get_task_context_with_parent() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());

        // Create parent-child relationship
        let parent = task_mgr.add_task("Parent task", None, None).await.unwrap();
        let child = task_mgr
            .add_task("Child task", None, Some(parent.id))
            .await
            .unwrap();

        let context = task_mgr.get_task_context(child.id).await.unwrap();

        // Verify task itself
        assert_eq!(context.task.id, child.id);
        assert_eq!(context.task.parent_id, Some(parent.id));

        // Should have 1 ancestor (the parent)
        assert_eq!(context.ancestors.len(), 1);
        assert_eq!(context.ancestors[0].id, parent.id);
        assert_eq!(context.ancestors[0].name, "Parent task");

        // No siblings
        assert_eq!(context.siblings.len(), 0);

        // No children
        assert_eq!(context.children.len(), 0);
    }

    #[tokio::test]
    async fn test_get_task_context_with_children() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());

        // Create parent with multiple children
        let parent = task_mgr.add_task("Parent task", None, None).await.unwrap();
        let child1 = task_mgr
            .add_task("Child 1", None, Some(parent.id))
            .await
            .unwrap();
        let child2 = task_mgr
            .add_task("Child 2", None, Some(parent.id))
            .await
            .unwrap();
        let child3 = task_mgr
            .add_task("Child 3", None, Some(parent.id))
            .await
            .unwrap();

        let context = task_mgr.get_task_context(parent.id).await.unwrap();

        // Verify task itself
        assert_eq!(context.task.id, parent.id);

        // No ancestors (root task)
        assert_eq!(context.ancestors.len(), 0);

        // No siblings
        assert_eq!(context.siblings.len(), 0);

        // Should have 3 children
        assert_eq!(context.children.len(), 3);
        let child_ids: Vec<i64> = context.children.iter().map(|t| t.id).collect();
        assert!(child_ids.contains(&child1.id));
        assert!(child_ids.contains(&child2.id));
        assert!(child_ids.contains(&child3.id));
    }

    #[tokio::test]
    async fn test_get_task_context_multi_level_hierarchy() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());

        // Create 3-level hierarchy: grandparent -> parent -> child
        let grandparent = task_mgr.add_task("Grandparent", None, None).await.unwrap();
        let parent = task_mgr
            .add_task("Parent", None, Some(grandparent.id))
            .await
            .unwrap();
        let child = task_mgr
            .add_task("Child", None, Some(parent.id))
            .await
            .unwrap();

        let context = task_mgr.get_task_context(child.id).await.unwrap();

        // Verify task itself
        assert_eq!(context.task.id, child.id);

        // Should have 2 ancestors (parent and grandparent, ordered from immediate to root)
        assert_eq!(context.ancestors.len(), 2);
        assert_eq!(context.ancestors[0].id, parent.id);
        assert_eq!(context.ancestors[0].name, "Parent");
        assert_eq!(context.ancestors[1].id, grandparent.id);
        assert_eq!(context.ancestors[1].name, "Grandparent");

        // No siblings
        assert_eq!(context.siblings.len(), 0);

        // No children
        assert_eq!(context.children.len(), 0);
    }

    #[tokio::test]
    async fn test_get_task_context_complex_family_tree() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());

        // Create complex structure:
        // Root
        //  ├─ Child1
        //  │   ├─ Grandchild1
        //  │   └─ Grandchild2 (target)
        //  └─ Child2

        let root = task_mgr.add_task("Root", None, None).await.unwrap();
        let child1 = task_mgr
            .add_task("Child1", None, Some(root.id))
            .await
            .unwrap();
        let child2 = task_mgr
            .add_task("Child2", None, Some(root.id))
            .await
            .unwrap();
        let grandchild1 = task_mgr
            .add_task("Grandchild1", None, Some(child1.id))
            .await
            .unwrap();
        let grandchild2 = task_mgr
            .add_task("Grandchild2", None, Some(child1.id))
            .await
            .unwrap();

        // Get context for grandchild2
        let context = task_mgr.get_task_context(grandchild2.id).await.unwrap();

        // Verify task itself
        assert_eq!(context.task.id, grandchild2.id);

        // Should have 2 ancestors: child1 and root
        assert_eq!(context.ancestors.len(), 2);
        assert_eq!(context.ancestors[0].id, child1.id);
        assert_eq!(context.ancestors[1].id, root.id);

        // Should have 1 sibling: grandchild1
        assert_eq!(context.siblings.len(), 1);
        assert_eq!(context.siblings[0].id, grandchild1.id);

        // No children
        assert_eq!(context.children.len(), 0);

        // Now get context for child1 to verify it sees both grandchildren
        let context_child1 = task_mgr.get_task_context(child1.id).await.unwrap();
        assert_eq!(context_child1.ancestors.len(), 1);
        assert_eq!(context_child1.ancestors[0].id, root.id);
        assert_eq!(context_child1.siblings.len(), 1);
        assert_eq!(context_child1.siblings[0].id, child2.id);
        assert_eq!(context_child1.children.len(), 2);
    }

    #[tokio::test]
    async fn test_get_task_context_respects_priority_ordering() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());

        // Create parent with children having different priorities
        let parent = task_mgr.add_task("Parent", None, None).await.unwrap();

        // Add children with priorities (lower number = higher priority)
        let child_low = task_mgr
            .add_task("Low priority", None, Some(parent.id))
            .await
            .unwrap();
        let _ = task_mgr
            .update_task(child_low.id, None, None, None, None, None, Some(10))
            .await
            .unwrap();

        let child_high = task_mgr
            .add_task("High priority", None, Some(parent.id))
            .await
            .unwrap();
        let _ = task_mgr
            .update_task(child_high.id, None, None, None, None, None, Some(1))
            .await
            .unwrap();

        let child_medium = task_mgr
            .add_task("Medium priority", None, Some(parent.id))
            .await
            .unwrap();
        let _ = task_mgr
            .update_task(child_medium.id, None, None, None, None, None, Some(5))
            .await
            .unwrap();

        let context = task_mgr.get_task_context(parent.id).await.unwrap();

        // Children should be ordered by priority (1, 5, 10)
        assert_eq!(context.children.len(), 3);
        assert_eq!(context.children[0].priority, Some(1));
        assert_eq!(context.children[1].priority, Some(5));
        assert_eq!(context.children[2].priority, Some(10));
    }

    #[tokio::test]
    async fn test_get_task_context_nonexistent_task() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());

        let result = task_mgr.get_task_context(99999).await;
        assert!(result.is_err());
        assert!(matches!(result, Err(IntentError::TaskNotFound(99999))));
    }

    #[tokio::test]
    async fn test_get_task_context_handles_null_priority() {
        let ctx = TestContext::new().await;
        let task_mgr = TaskManager::new(ctx.pool());

        // Create siblings with mixed null and set priorities
        let task1 = task_mgr.add_task("Task 1", None, None).await.unwrap();
        let _ = task_mgr
            .update_task(task1.id, None, None, None, None, None, Some(1))
            .await
            .unwrap();

        let task2 = task_mgr.add_task("Task 2", None, None).await.unwrap();
        // task2 has NULL priority

        let task3 = task_mgr.add_task("Task 3", None, None).await.unwrap();
        let _ = task_mgr
            .update_task(task3.id, None, None, None, None, None, Some(5))
            .await
            .unwrap();

        let context = task_mgr.get_task_context(task2.id).await.unwrap();

        // Should have 2 siblings, ordered by priority (non-null first, then null)
        assert_eq!(context.siblings.len(), 2);
        // Task with priority 1 should come first
        assert_eq!(context.siblings[0].id, task1.id);
        assert_eq!(context.siblings[0].priority, Some(1));
        // Task with priority 5 should come second
        assert_eq!(context.siblings[1].id, task3.id);
        assert_eq!(context.siblings[1].priority, Some(5));
    }
}