import os
import requests
import logging
from fastmcp import FastMCP

# --- Configuration ---
VIKUNJA_URL = os.getenv("VIKUNJA_URL")
VIKUNJA_USERNAME = os.getenv("VIKUNJA_USERNAME")
VIKUNJA_PASSWORD = os.getenv("VIKUNJA_PASSWORD")
LOG_LEVEL = os.getenv("LOG_LEVEL", "INFO")
DEBUG_TASK_MATCHES = os.getenv("DEBUG_TASK_MATCHES", "false").lower() in ("1", "true", "yes")

# --- MCP Application Setup ---
mcp = FastMCP()
session = requests.Session()

# Configure basic logging. Level can be controlled with LOG_LEVEL env var.
level = getattr(logging, LOG_LEVEL.upper(), logging.INFO)
logging.basicConfig(level=level, format='%(asctime)s %(levelname)s %(message)s')
logger = logging.getLogger(__name__)
if DEBUG_TASK_MATCHES:
    logger.info("DEBUG_TASK_MATCHES is enabled: per-task match attempts will be logged at INFO level")

# --- Input Validation ---
if not all([VIKUNJA_URL, VIKUNJA_USERNAME, VIKUNJA_PASSWORD]):
    print("Error: Please set the VIKUNJA_URL, VIKUNJA_USERNAME, and VIKUNJA_PASSWORD environment variables.")
    exit(1)

@mcp.tool()
def login():
    """
    Authenticates with the Vikunja API to get a session token.
    """
    global session
    try:
        response = session.post(
            f"{VIKUNJA_URL}/api/v1/login",
            json={"username": VIKUNJA_USERNAME, "password": VIKUNJA_PASSWORD}
        )
        response.raise_for_status()
        token = response.json().get("token")
        if not token:
            return "Login failed: Token not found in response."
        
        session.headers.update({"Authorization": f"Bearer {token}"})
        return "Login successful. Token stored for session."
    except requests.exceptions.RequestException as e:
        return f"Login failed: {e}"

@mcp.tool()
def search_tasks(query: str):
    """
    Searches for tasks in Vikunja.
    
    :param query: The search string to use for finding tasks.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."
    
    try:
        # Vikunja does not expose a /tasks/search endpoint in the public API.
        # Fetch all tasks and filter client-side by title/description.
        logger.info("search_tasks: fetching all tasks from %s", f"{VIKUNJA_URL}/api/v1/tasks/all")
        
        all_tasks = []
        page = 1
        per_page = 50 
        
        while True:
            response = session.get(f"{VIKUNJA_URL}/api/v1/tasks/all?page={page}&limit={per_page}")
            response.raise_for_status()
            data = response.json()
            tasks = data if isinstance(data, list) else data.get("tasks", [])
            if not tasks:
                break
            all_tasks.extend(tasks)
            page += 1

        tasks = all_tasks

        q = (query or "").strip()
        logger.info("search_tasks: raw query='%s'", q)
        if not q:
            logger.info("search_tasks: empty query, returning %d tasks", len(tasks))
            return tasks

        terms = [t.lower() for t in q.split() if t]
        logger.info("search_tasks: parsed terms=%s", terms)

        def matches(task: dict) -> bool:
            title = (task.get("title") or "")
            description = (task.get("description") or "")
            title_l = title.lower()
            desc_l = description.lower()
            for term in terms:
                if term in title_l or term in desc_l:
                    logger.debug("search_tasks: task id=%s matched term='%s' (title=%r, description=%r)", task.get("id"), term, title, description)
                    return True
                else:
                    logger.debug("search_tasks: task id=%s did not match term='%s' (title=%r)", task.get("id"), term, title)
            return False

        filtered = [t for t in tasks if matches(t)]
        logger.info("search_tasks: fetched=%d filtered=%d", len(tasks), len(filtered))
        return filtered
    except requests.exceptions.RequestException as e:
        logger.exception("search_tasks: request failed")
        return f"Error searching tasks: {e}"

@mcp.tool()
def active_tasks(project_id: int = None, is_favorite: bool = None):
    """
    Returns a list of active tasks (where 'done' is False) from Vikunja.

    :param project_id: Optional project ID to filter tasks by project.
    :param is_favorite: Optional filter to return only tasks matching favorite status.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."

    try:
        logger.info("active_tasks: fetching all tasks from %s", f"{VIKUNJA_URL}/api/v1/tasks/all")

        all_tasks = []
        page = 1
        per_page = 50

        while True:
            response = session.get(f"{VIKUNJA_URL}/api/v1/tasks/all?page={page}&limit={per_page}")
            response.raise_for_status()
            data = response.json()
            tasks = data if isinstance(data, list) else data.get("tasks", [])
            if not tasks:
                break
            all_tasks.extend(tasks)
            page += 1

        # Filter active tasks (not done)
        active = [t for t in all_tasks if not t.get("done", False)]

        # If project_id provided, further filter by task's project_id
        if project_id is not None:
            before = len(active)
            active = [t for t in active if t.get("project_id") == project_id or t.get("projectID") == project_id]
            logger.info("active_tasks: filtered by project_id=%s before=%d after=%d", project_id, before, len(active))

        # If is_favorite provided, filter by is_favorite / is_favourite field
        if is_favorite is not None:
            before = len(active)
            def fav_val(task):
                return bool(task.get("is_favorite", task.get("is_favourite", False)))
            active = [t for t in active if fav_val(t) == bool(is_favorite)]
            logger.info("active_tasks: filtered by is_favorite=%s before=%d after=%d", is_favorite, before, len(active))

        logger.info("active_tasks: fetched=%d active=%d", len(all_tasks), len(active))
        return active
    except requests.exceptions.RequestException as e:
        logger.exception("active_tasks: request failed")
        return f"Error retrieving active tasks: {e}"

@mcp.tool()
def get_task_details(task_id: int):
    """
    Gets task details in Vikunja.

    :param task_id: The ID of the task of which to fetch comments.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."

    try:
        response = session.get(f"{VIKUNJA_URL}/api/v1/tasks/{task_id}")
        response.raise_for_status()
        details = response.json()
        if not details:
            return "No details found for this task."

    # Helpers to produce compact readable strings for nested structures
        def join_names(items):
            if not items:
                return "[]"
            out = []
            for it in items:
                if not isinstance(it, dict):
                    out.append(str(it))
                    continue
                out.append(str(it.get("name") or it.get("username") or it.get("id") or it))
            return ", ".join(out)

        def labels_list(labels):
            if not labels:
                return "[]"
            out = []
            for l in labels:
                if isinstance(l, dict):
                    out.append(str(l.get("title") or l.get("name") or l.get("id") or l))
                else:
                    out.append(str(l))
            return ", ".join(out)

        fetched_id = details.get("id", "N/A")
        title = details.get("title", "N/A")
        identifier = details.get("identifier", "N/A")
        created = details.get("created", "N/A")
        updated = details.get("updated", "N/A")
        created_by = details.get("created_by") or {}
        created_by_str = f"{created_by.get('name','N/A')} (id={created_by.get('id','N/A')}, email={created_by.get('email','N/A')}, username={created_by.get('username','N/A')})"

        description = details.get("description", "N/A")
        done = details.get("done", "N/A")
        done_at = details.get("done_at", "N/A")
        percent_done = details.get("percent_done", "N/A")
        due_date = details.get("due_date", "N/A")
        start_date = details.get("start_date", "N/A")
        end_date = details.get("end_date", "N/A")
        repeat_mode = details.get("repeat_mode", "N/A")
        repeat_after = details.get("repeat_after", "N/A")

        project_id = details.get("project_id", "N/A")
        bucket_id = details.get("bucket_id", "N/A")
        # Coerce potentially-None fields to safe defaults so len() and iteration are safe.
        # Vikunja may return null for some nested fields; normalize to empty lists/dicts
        # to avoid TypeError when calling len() or iterating.
        buckets = details.get("buckets") or []
        index = details.get("index", "N/A")
        position = details.get("position", "N/A")

        priority = details.get("priority", "N/A")
        is_favorite = details.get("is_favorite", details.get("is_favourite", "N/A"))
        hex_color = details.get("hex_color", "N/A")

        assignees = details.get("assignees") or []
        attachments = details.get("attachments") or []
        cover_image_attachment_id = details.get("cover_image_attachment_id", "N/A")
        comments = details.get("comments") or []
        labels = details.get("labels") or []
        reminders = details.get("reminders") or []
        reactions = details.get("reactions") or {}
        related_tasks = details.get("related_tasks") or {}
        subscription = details.get("subscription") or {}

        result = []
        result.append(f"ID: {fetched_id}, Identifier: {identifier}, Title: {title}")
        result.append(f"Created: {created} by {created_by_str}, Updated: {updated}")
        result.append(f"Done: {done} (done_at={done_at}), Percent Done: {percent_done}, Priority: {priority}, Favorite: {is_favorite}")
        result.append(f"Due Date: {due_date}, Start Date: {start_date}, End Date: {end_date}, Repeat Mode: {repeat_mode}, Repeat After: {repeat_after}")
        result.append(f"Project ID: {project_id}, Bucket ID: {bucket_id}, Buckets: {len(buckets)} items, Index: {index}, Position: {position}")
        result.append(f"Labels: {labels_list(labels)}, Hex Color: {hex_color}")
        result.append(f"Assignees: {join_names(assignees)}, Attachments Count: {len(attachments)}, Cover Image Attachment ID: {cover_image_attachment_id}")
        result.append(f"Comments Count: {len(comments)}, Reminders Count: {len(reminders)}")
        result.append(f"Reactions: {reactions}, Related Tasks: {related_tasks}, Subscription: {subscription}")
        result.append(f"Description: {description}")

        return "\n".join(result)

    except requests.exceptions.RequestException as e:
        logger.exception("get_task_details: request failed for task_id=%s", task_id)
        return f"Error looking up details for task: {e}"
    
@mcp.tool()
def add_task(project_id: int, title: str, description: str = ""):
    """
    Adds a new task to a Vikunja project.
    
    :param project_id: The ID of the project to add the task to.
    :param title: The title of the new task.
    :param description: An optional description for the task.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."
        
    task_payload = {
        "project_id": project_id,
        "title": title,
        "description": description
    }
    
    try:
        response = session.put(
            f"{VIKUNJA_URL}/api/v1/projects/{project_id}/tasks",
            json=task_payload
        )
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as e:
        return f"Error adding task: {e}"

@mcp.tool()
def update_task_title(task_id: int, title: str):
    """
    Updates an existing title on a task.

    :param task_id: The ID of the task.
    :param title: The updated title text.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."

    if not (title or "").strip():
        return "Title cannot be empty."
        
    task_payload = {
        "title": title
    }

    try:
        response = session.post(
            f"{VIKUNJA_URL}/api/v1/tasks/{task_id}",
            json=task_payload
        )
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as e:
        logger.exception("update_task_title: request failed for task_id=%s", task_id)
        return f"Error updating task title: {e}"

@mcp.tool()
def update_task_description(task_id: int, description: str):
    """
    Updates an existing description on a task.

    :param task_id: The ID of the task.
    :param description: The updated description text.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."

    if not (description or "").strip():
        return "Description cannot be empty."
        
    task_payload = {
        "description": description
    }

    try:
        response = session.post(
            f"{VIKUNJA_URL}/api/v1/tasks/{task_id}",
            json=task_payload
        )
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as e:
        logger.exception("update_task_description: request failed for task_id=%s", task_id)
        return f"Error updating task description: {e}"

@mcp.tool()
def delete_task(task_id: int):
    """
    Deletes an existing task.

    :param task_id: The ID of the task.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."

    try:
        response = session.delete(f"{VIKUNJA_URL}/api/v1/tasks/{task_id}")
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as e:
        logger.exception("delete_task: request failed for task_id=%s", task_id)
        return f"Error deleting task: {e}"
    
@mcp.tool()
def close_task(task_id: int):
    """
    Closes (marks as done) a task in Vikunja.
    
    :param task_id: The ID of the task to close.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."
    
    task_payload = {
        "done": True
    }
    
    try:
        response = session.post(
            f"{VIKUNJA_URL}/api/v1/tasks/{task_id}",
            json=task_payload
        )
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as e:
        return f"Error closing task: {e}"

@mcp.tool()
def comment_task(task_id: int, description: str):
    """
    Adds a comment to a task in Vikunja.

    :param task_id: The ID of the task to comment on.
    :param description: The text of the comment to add.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."

    if not (description or "").strip():
        return "Comment description cannot be empty."

    payload = {"comment": description}

    try:
        response = session.put(
            f"{VIKUNJA_URL}/api/v1/tasks/{task_id}/comments",
            json=payload
        )
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as e:
        logger.exception("comment_task: request failed for task_id=%s", task_id)
        return f"Error adding comment to task: {e}"

@mcp.tool()
def lookup_comment_task(task_id: int):
    """
    Lists comments in a task in Vikunja.

    :param task_id: The ID of the task of which to fetch comments.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."

    try:
        response = session.get(f"{VIKUNJA_URL}/api/v1/tasks/{task_id}/comments")
        response.raise_for_status()
        comments = response.json()
        if not comments:
            return "No comments found for this task."
        
        result = []
        for comment in comments:
            comment_id = comment.get("id", "N/A")
            comment_text = comment.get("comment", "N/A")
            comment_created = comment.get("created", "N/A")
            comment_author = comment.get("author", "N/A")
            result.append(f"ID: {comment_id}, Created: {comment_created}, Author: {comment_author}, Comment: {comment_text}")
        return "\n".join(result)
    
    except requests.exceptions.RequestException as e:
        logger.exception("lookup_comment_task: request failed for task_id=%s", task_id)
        return f"Error looking up comments to task: {e}"

@mcp.tool()
def update_comment(task_id: int, comment_id: int, comment: str):
    """
    Updates an existing comment on a task.

    :param task_id: The ID of the task.
    :param comment_id: The ID of the comment to update.
    :param comment: The updated comment text.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."

    if not (comment or "").strip():
        return "Comment cannot be empty."

    payload = {"comment": comment}

    try:
        response = session.post(
            f"{VIKUNJA_URL}/api/v1/tasks/{task_id}/comments/{comment_id}",
            json=payload
        )
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as e:
        logger.exception("update_comment: request failed for task_id=%s, comment_id=%s", task_id, comment_id)
        return f"Error updating comment for task: {e}"
    
@mcp.tool()
def lookup_project():
    """
    Retrieves all projects the user has access to and lists them by name and ID.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."
    
    try:
        response = session.get(f"{VIKUNJA_URL}/api/v1/projects")
        response.raise_for_status()
        projects = response.json()
        
        if not projects:
            return "No projects found."
        
        result = []
        for project in projects:
            project_id = project.get("id", "N/A")
            project_title = project.get("title", "Untitled")
            result.append(f"ID: {project_id}, Name: {project_title}")
        
        return "\n".join(result)
    except requests.exceptions.RequestException as e:
        return f"Error retrieving projects: {e}"


@mcp.tool()
def create_project(title: str, description: str = "", is_favorite: bool = False):
    """
    Creates a new project in Vikunja.

    :param title: The title of the project.
    :param description: Optional description for the project.
    :param is_favorite: Whether the project should be marked as favorite.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."

    if not (title or "").strip():
        return "Project title cannot be empty."

    payload = {
        "title": title,
        "description": description,
        "is_favourite": bool(is_favorite)
    }

    try:
        response = session.put(
            f"{VIKUNJA_URL}/api/v1/projects",
            json=payload
        )
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as e:
        logger.exception("create_project: request failed for title=%s", title)
        return f"Error creating project: {e}"

@mcp.tool()
def update_task_details(
    task_id: int,
    title: str = None,
    description: str = None,
    done: bool = None,
    percent_done: int = None,
    due_date: str = None,
    start_date: str = None,
    end_date: str = None,
    repeat_mode: int = None,
    repeat_after: int = None,
    project_id: int = None,
    bucket_id: int = None,
    priority: int = None,
    position: int = None,
    is_favorite: bool = None,
    hex_color: str = None,
    labels: str = None,
):
    """
    Updates any primary fields on a task. Only fields provided (not None) will be sent.
    If `labels` is provided as a comma-separated string, it will replace existing labels.
    """
    if "Authorization" not in session.headers:
        return "Please run the 'login' command first."

    payload = {}

    # Simple helper to set only when value explicitly passed (not None)
    def set_if(provided, key, transform=lambda x: x):
        if provided is not None:
            payload[key] = transform(provided)

    set_if(title, "title")
    set_if(description, "description")
    set_if(done, "done")
    set_if(percent_done, "percent_done")
    set_if(due_date, "due_date")
    set_if(start_date, "start_date")
    set_if(end_date, "end_date")
    set_if(repeat_mode, "repeat_mode")
    set_if(repeat_after, "repeat_after")
    set_if(project_id, "project_id")
    set_if(bucket_id, "bucket_id")
    set_if(priority, "priority")
    set_if(position, "position")
    set_if(is_favorite, "is_favorite") 
    set_if(hex_color, "hex_color")

    # Replace labels if provided as comma-separated string
    if labels is not None:
        if isinstance(labels, str):
            parsed = [s.strip() for s in labels.split(",") if s.strip()]
            payload["labels"] = parsed
        else:
            # Allow callers to pass list directly
            payload["labels"] = labels

    if not payload:
        return "No fields provided to update."

    try:
        logger.info("update_task_details: updating task_id=%s with payload keys=%s", task_id, list(payload.keys()))
        response = session.post(f"{VIKUNJA_URL}/api/v1/tasks/{task_id}", json=payload)
        response.raise_for_status()
        return response.json()
    except requests.exceptions.RequestException as e:
        logger.exception("update_task_details: request failed for task_id=%s", task_id)
        return f"Error updating task details: {e}"

if __name__ == "__main__":
    print("--- Vikunja MCP Client ---")
    print("Available commands: login, search_tasks, add_task, close_task, lookup_project, help, exit")
    mcp.run()