from __future__ import annotations

from datetime import date
from pathlib import Path
import re

from .tasks import read_tasks


def project_stage(root: Path) -> str:
    if not (root / "context" / "discovery-log.md").exists():
        return "NOT_INITIALISED"
    tasks = read_tasks(root)
    if not tasks:
        return "DISCOVERY"
    if any(task.status.lower() == "in progress" for task in tasks):
        return "BUILDING"
    if any(task.status.lower() == "todo" for task in tasks):
        return "TASKS_READY"
    return "REVIEW_READY"


def task_counts(root: Path) -> dict[str, int]:
    counts: dict[str, int] = {}
    for task in read_tasks(root):
        counts[task.status] = counts.get(task.status, 0) + 1
    return counts


_CURRENT_TASK_RE = re.compile(r"^(Current Task): .+$", re.MULTILINE)
_UPDATED_RE = re.compile(r"^(Last Updated): .+$", re.MULTILINE)


def update_project_state(root: Path, task_id: str = "None") -> bool:
    """Update PROJECT_STATE.md current task and timestamp."""
    path = root / "PROJECT_STATE.md"
    if not path.exists():
        return False

    text = path.read_text(encoding="utf-8")
    text = _CURRENT_TASK_RE.sub(f"Current Task: {task_id}", text, count=1)
    text = _UPDATED_RE.sub(f"Last Updated: {date.today().isoformat()}", text, count=1)
    path.write_text(text, encoding="utf-8")
    return True


_STAGE_RE = re.compile(r"(## Current Stage\n\n)[\s\S]+?(?=\n)", re.MULTILINE | re.DOTALL)
_TASK_RE = re.compile(r"(## Current Task\n\n)[\s\S]+?(?=\n)", re.MULTILINE | re.DOTALL)


def update_agent_handoff(root: Path, task_id: str = "None") -> bool:
    """Update AGENT_HANDOFF.md current stage and task."""
    path = root / "AGENT_HANDOFF.md"
    if not path.exists():
        return False

    text = path.read_text(encoding="utf-8")
    stage = project_stage(root)
    text = _STAGE_RE.sub(f"## Current Stage\n\n{stage}", text, count=1)
    text = _TASK_RE.sub(f"## Current Task\n\n{task_id}", text, count=1)
    path.write_text(text, encoding="utf-8")
    return True