"""Dispatches work to a single CodingAgent, one repo at a time."""

import logging
import re
from typing import Any
from core.coding_agent import CodingAgent
from core.queue import WorkItem
from gitea.tools.coding_tools import CodingTools
from gitea.tools.gitea_tools import GiteaTools
from gitea.client import GiteaClient
from core.coding_prompt import CODING_AGENT_SYSTEM_PROMPT
from gitea.config import AGENT_MODEL_ID
from gitea.workspace import WorkspaceManager
from gitea.models import CommentModel, PullRequestFileModel, PullRequestModel, IssueModel

logger: logging.Logger = logging.getLogger("agent-dispatcher")

AGENT_USERNAMES: frozenset[str] = frozenset({"meeks-ai", "agent-bot"})

CLOSE_KEYWORDS_PATTERN = re.compile(
    rf"\b(?:close|closes|closed|fix|fixes|fixed|resolve|resolves|resolved)\s+#(\d+)\b",
    re.IGNORECASE
)


class AgentDispatcher:
    """Dispatches work to a single CodingAgent, one repo at a time."""

    def __init__(
        self,
        client: GiteaClient,
        tools: GiteaTools,
        model_name: str = AGENT_MODEL_ID,
        max_retries: int = 2,
    ) -> None:
        self._client = client
        self._tools = tools
        self._model_name = model_name
        self._max_retries = max_retries

    def _find_pr_for_issue(self, repo_full_name: str, issue_number: int) -> PullRequestModel | None:
        """Find an open pull request that addresses the given issue number."""
        owner, repo_name = repo_full_name.split("/")
        try:
            prs = self._client.list_repo_pull_requests(owner, repo_name)
            for pr in prs:
                ref = pr.head.get("ref", "") if pr.head else ""
                if re.search(rf"(?<!\d){issue_number}(?!\d)", ref):
                    return pr
                body = pr.body or ""
                title = pr.title or ""
                matches = CLOSE_KEYWORDS_PATTERN.findall(body) + CLOSE_KEYWORDS_PATTERN.findall(title)
                if any(int(m) == issue_number for m in matches):
                    return pr
                issue_ref_pattern = re.compile(rf"(?<!\w)#{issue_number}\b")
                if issue_ref_pattern.search(title) or issue_ref_pattern.search(body):
                    return pr
        except Exception as e:
            logger.warning(f"Error checking PRs for issue #{issue_number} in {repo_full_name}: {e}")
        return None

    def _find_issues_for_pr(self, pr_body: str) -> list[int]:
        """Extract referenced issue numbers from the PR body."""
        matches = CLOSE_KEYWORDS_PATTERN.findall(pr_body)
        return list(set(int(m) for m in matches))

    def _is_awaiting_reply(self, comments: list[CommentModel]) -> bool:
        """Return True if the agent's most recent comment contains the
        awaiting-reply marker AND no human has commented after it.
        The agent itself embeds the marker when it needs human input.
        """
        if not comments:
            return False
        # Find the last agent comment index
        last_agent_idx: int = -1
        for i, c in enumerate(comments):
            if c.user and c.user.login in AGENT_USERNAMES:
                last_agent_idx = i
        if last_agent_idx == -1:
            return False
        last_agent_comment = comments[last_agent_idx]
        body = (last_agent_comment.body or "")
        # The agent explicitly embeds this marker when it is waiting for input
        if "<!-- agent:awaiting-reply -->" not in body:
            return False
        # Check if any human replied AFTER the last agent comment
        for c in comments[last_agent_idx + 1:]:
            if c.user and c.user.login not in AGENT_USERNAMES:
                return False  # Human replied — we can proceed
        return True  # Agent signalled wait, no human replied yet

    async def dispatch(
        self,
        repo: str,
        work_items: list[WorkItem],
    ) -> list[str]:
        """Dispatch all work for a single repo to a fresh agent, then discard it."""
        workspace = WorkspaceManager()
        repo_path = workspace.get_repo_path(repo)
        coding_tools = CodingTools(str(repo_path))

        planning_tools: list[Any] = [
            self._tools.get_issue,
            self._tools.get_pull_request,
            self._tools.list_issues,
            self._tools.list_pull_requests,
            self._tools.get_file_content,
            self._tools.get_issue_comments,
            self._tools.get_pull_request_comments,
            self._tools.get_pull_request_diff,
            self._tools.get_pull_request_patch,
            coding_tools.list_files,
            coding_tools.read_file,
            coding_tools.grep_search,
            coding_tools.get_working_directory,
            coding_tools.run_command,
        ]

        coding_tools_list: list[Any] = [
            self._tools.get_issue,
            self._tools.get_pull_request,
            self._tools.list_issues,
            self._tools.list_pull_requests,
            self._tools.get_file_content,
            self._tools.create_pull_request,
            self._tools.add_label_to_issue,
            self._tools.add_label_to_pr,
            self._tools.create_branch,
            self._tools.commit_file,
            self._tools.create_issue,
            self._tools.add_comment_to_issue,
            self._tools.close_issue,
            self._tools.close_pull_request,
            self._tools.get_issue_comments,
            self._tools.get_pull_request_comments,
            self._tools.add_comment,
            self._tools.add_label,
            self._tools.update_file,
            self._tools.get_pull_request_diff,
            self._tools.get_pull_request_patch,
            self._tools.approve_pull_request,
            self._tools.request_changes,
            coding_tools.list_files,
            coding_tools.read_file,
            coding_tools.write_file,
            coding_tools.edit_file,
            coding_tools.run_command,
            coding_tools.grep_search,
            coding_tools.get_working_directory,
        ]

        results: list[str] = []

        import os
        original_cwd = os.getcwd()
        changed_dir = False
        if os.path.isdir(str(repo_path)):
            os.chdir(str(repo_path))
            changed_dir = True
        try:
            for item in work_items:
                if item.task_type == "issue":
                    existing_pr = self._find_pr_for_issue(repo, item.task_number)
                    if existing_pr:
                        logger.info(f"Issue #{item.task_number} already has open PR #{existing_pr.number}. Skipping.")
                        results.append(f"SKIP: A pull request (PR #{existing_pr.number}) addressing issue #{item.task_number} already exists.")
                        continue

                    # Check if we're waiting for a human reply before acting
                    owner, repo_name = repo.split("/")
                    issue_comments = []
                    try:
                        issue_comments = self._client.get_issue_comments(owner, repo_name, item.task_number)
                    except Exception:
                        pass
                    if self._is_awaiting_reply(issue_comments):
                        logger.info(f"Issue #{item.task_number}: agent asked a question and is awaiting a human reply. Skipping.")
                        results.append(f"SKIP: Awaiting human reply on issue #{item.task_number}.")
                        continue

                elif item.task_type == "pr":
                    # Check if we're waiting for a human reply before acting on a PR
                    owner, repo_name = repo.split("/")
                    pr_comments = []
                    try:
                        pr_comments = self._client.get_pull_request_comments(owner, repo_name, item.task_number)
                    except Exception:
                        pass
                    if self._is_awaiting_reply(pr_comments):
                        logger.info(f"PR #{item.task_number}: agent asked a question and is awaiting a human reply. Skipping.")
                        results.append(f"SKIP: Awaiting human reply on PR #{item.task_number}.")
                        continue

                for attempt in range(1, self._max_retries + 1):
                    try:
                        if item.task_type == "issue":
                            base_mission = self._build_issue_mission(item)
                        else:
                            base_mission = self._build_pr_mission(item)

                        if base_mission.startswith("SKIP:"):
                            logger.info(f"Skipping task #{item.task_number}: {base_mission}")
                            results.append(base_mission)
                            break

                        # Step 1: Planning Phase
                        logger.info(f"Starting Planning Phase for {item.task_type} #{item.task_number} (attempt {attempt})")
                        planning_mission = (
                            f"PHASE 1: PLANNING PHASE\n\n"
                            f"Your task is to analyze the repository structure and create a detailed implementation plan.\n"
                            f"Original Mission details:\n{base_mission}\n\n"
                            f"CRITICAL RULES:\n"
                            f"1. You are ONLY generating an implementation plan. DO NOT write files, DO NOT edit files, DO NOT commit, DO NOT push, and DO NOT create branches or PRs.\n"
                            f"2. Explore the codebase using read_file, list_files, grep_search, or run_command (for read-only queries like find/grep).\n"
                            f"3. Output your final plan clearly, describing the exact changes to be made and which files to modify.\n"
                        )
                        planning_agent = CodingAgent(self._model_name)
                        plan = await planning_agent.run_with_tools(planning_mission, planning_tools)
                        logger.info(f"Generated Plan:\n{plan}")

                        # Step 2: Coding Phase
                        logger.info(f"Starting Execution/Coding Phase for {item.task_type} #{item.task_number} (attempt {attempt})")
                        coding_mission = (
                            f"PHASE 2: EXECUTION/CODING PHASE\n\n"
                            f"You must now implement the changes based on the following plan generated in Phase 1:\n"
                            f"--- PLAN ---\n{plan}\n--- PLAN END ---\n\n"
                            f"Original Mission details:\n{base_mission}\n\n"
                            f"Follow the repository workflow to make the changes, verify them, commit, push, and create a PR.\n"
                        )
                        coding_agent = CodingAgent(self._model_name)
                        response = await coding_agent.run_with_tools(coding_mission, coding_tools_list)
                        logger.info(f"Agent response for {item.task_type} #{item.task_number}: {response}")
                        results.append(response)
                        break
                    except Exception as e:
                        logger.error(f"Error processing {item.task_type} #{item.task_number} (attempt {attempt}/{self._max_retries}): {e}")
                        if attempt == self._max_retries:
                            results.append(f"FAILED after {self._max_retries} attempts: {str(e)}")
        finally:
            if changed_dir:
                os.chdir(original_cwd)

        return results

    def _build_issue_mission(self, item: WorkItem) -> str:
        issue_info = item.task_info
        assert isinstance(issue_info, IssueModel)


        repo_full_name: str = item.repo_full_name
        issue_number: int = item.task_number

        issue_body: str = issue_info.body or "No description provided."
        issue_labels: list[str] = [lbl.name for lbl in issue_info.labels]
        issue_user: str = issue_info.user.login if issue_info.user else "unknown"
        issue_created: str = issue_info.created_at or "unknown"
        title: str = issue_info.title


        owner: str = repo_full_name.split("/")[0]
        repo_name: str = repo_full_name.split("/")[1]

        comments: list[CommentModel] = []
        try:
            comments = self._client.get_issue_comments(owner, repo_name, issue_number)
        except Exception:
            pass

        labels_str: str = f"Labels: {', '.join(issue_labels)}" if issue_labels else "Labels: none"
        comments_str: str = "\n".join([
            f"- @{c.user.login} ({c.created_at}): {c.body}"
            for c in comments
        ]) if comments else "No comments yet."

        clean_title = re.sub(r'[^a-zA-Z0-9\s-]', '', title).strip().lower()
        title_words = clean_title.split()[:5]
        desc_suffix = "-".join(title_words)
        if not desc_suffix:
            desc_suffix = "fix-issue"
        branch_name: str = f"fix/issue-{issue_number}-{desc_suffix}"

        workspace = WorkspaceManager()
        repo_path = workspace.get_repo_path(repo_full_name)

        return (
            f"Your mission is to resolve issue #{issue_number} in {repo_full_name}.\n\n"
            f"Issue: {title}\n"
            f"Author: @{issue_user} (created {issue_created})\n"
            f"{labels_str}\n\n"
            f"Description:\n{issue_body}\n\n"
            f"Comments ({len(comments)}):\n{comments_str}\n\n"
            f"Branch name: {branch_name}.\n\n"
            "BEFORE WRITING ANY CODE:\n"
            "  - Search online for relevant documentation, known solutions, library APIs, and platform-specific behavior.\n"
            "  - If ANY part of the issue is unclear, ambiguous, or has multiple valid approaches:\n"
            "    → Post a comment on the issue using `add_comment_to_issue` with your specific question(s).\n"
            "    → List the approaches you are considering.\n"
            "    → End the comment with the marker: <!-- agent:awaiting-reply --> on its own line.\n"
            "    → STOP. Do NOT proceed until a human replies. The system will re-dispatch you once a human responds.\n"
            "  - Never assume or guess. Always prefer asking over guessing.\n\n"
            "CRITICAL INSTRUCTIONS:\n"
            f"1. The repo is already cloned locally at '{repo_path}'. DO NOT create a new repository.\n"
            f"   The repository directory is your current working directory (cwd). You can verify this via the `get_working_directory` tool.\n"
            "2. Always start from master: `git checkout master && git pull origin master`\n"
            "3. Branch from master: `git checkout -b <type>/issue-<number>-<descriptive-name>`\n"
            "   Branch names MUST include a descriptive name (words/hyphens), not just the issue number.\n"
            "   Types: feat, fix, chore, docs, style, refactor, test, build, ci, perf\n"
            "4. Use `edit_file`/`write_file` for code changes, then `git add` and `git commit` via `run_command`.\n"
            "5. Push: `git push origin <branch>` via `run_command`.\n"
            "6. Create PR: Use the `create_pull_request` tool (do NOT use Gitea's `tea` CLI or GitHub's `gh` CLI in run_command, as they can hang/freeze interactively).\n"
            "   PR description MUST include the Gitea automation template with 'closes #<ISSUE>'.\n"
            "7. IMPORTANT: After successfully creating the pull request, you MUST comment on the issue (using the `add_comment_to_issue` tool) with the PR number, PR link, and summary.\n"
            "8. Check AGENTS.md in repo root for project conventions and verification steps.\n"
            "9. Grade severity: Critical/High = fix, Medium = review/fix, Low = skip.\n"
            "An issue is DONE when the connected PR is merged (you cannot merge yourself).\n"
            "DO NOT edit .git files unless explicitly resolving a git issue.\n"
            "DO NOT work on non-meeks organization repos."
        )

    def _build_pr_mission(self, item: WorkItem) -> str:
        pr_info = item.task_info
        assert isinstance(pr_info, PullRequestModel)


        repo_full_name: str = item.repo_full_name
        pr_number: int = item.task_number

        owner: str = repo_full_name.split("/")[0]
        repo_name: str = repo_full_name.split("/")[1]

        pr_model = self._client.get_pull_request(owner, repo_name, pr_number)
        pr_details: str = pr_model.model_dump_json(indent=2)
        pr_diff: str = ""
        try:
            pr_diff = self._client.get_pull_request_diff(owner, repo_name, pr_number)
        except Exception as e:
            logger.warning(f"Could not fetch PR diff for #{pr_number}: {e}")
            pr_diff = f"Error fetching diff: {e}"


        pr_files: list[PullRequestFileModel] = []
        try:
            pr_files = self._client.get_pull_request_files(owner, repo_name, pr_number)
        except Exception:
            pass

        files_summary: str = "\n".join([f"- {f.filename}" for f in pr_files]) if pr_files else "No files available."

        comments: list[CommentModel] = []
        try:
            comments = self._client.get_pull_request_comments(owner, repo_name, pr_number)
            if not isinstance(comments, list):
                comments = []
        except Exception:
            pass

        reviews: list[dict[str, Any]] = []
        try:
            reviews = self._client.get_pr_reviews(owner, repo_name, pr_number)
            if not isinstance(reviews, list):
                reviews = []
        except Exception:
            pass

        ai_username = "meeks-ai"
        try:
            user = self._client.get_authenticated_user()
            if user:
                ai_username = user.login
        except Exception:
            pass

        # Create a combined, sorted timeline of timeline comments and reviews
        timeline: list[dict[str, Any]] = []
        for c in comments:
            timeline.append({
                "timestamp": c.created_at or "",
                "user": c.user.login,
                "type": "comment",
                "body": c.body,
                "by_ai": "Reviewed by AI Agent" in c.body or c.user.login == ai_username
            })
        for r in reviews:
            r_user = (r.get("user") or {}).get("login", "unknown")
            r_body = r.get("body", "")
            r_state = r.get("state", "")
            timeline.append({
                "timestamp": r.get("submitted_at") or r.get("updated_at") or "",
                "user": r_user,
                "type": "review",
                "body": f"[{r_state}] {r_body}",
                "by_ai": r_user == ai_username
            })

        timeline.sort(key=lambda x: x["timestamp"])

        last_action_by_ai = False
        if timeline:
            last_action_by_ai = timeline[-1]["by_ai"]

        pr_author: str = pr_info.user.login if pr_info.user else "unknown"
        is_own_pr = (pr_author == ai_username)

        # Skip if the latest action is already by AI (waiting for human turn)
        if last_action_by_ai:
            logger.info(f"PR #{pr_number} already addressed by AI. Skipping.")
            return f"SKIP: PR #{pr_number} has already been addressed by AI. No new action needed."

        comments_str: str = "\n".join([
            f"- @{c.user.login} ({c.created_at}): {c.body}"
            for c in comments
        ]) if comments else "No comments yet."

        reviews_str: str = "\n".join([
            f"- @{(r.get('user') or {}).get('login')} ({r.get('submitted_at')}): [{r.get('state')}] {r.get('body')}"
            for r in reviews
        ]) if reviews else "No reviews yet."

        connected_issues_ctx = ""
        pr_body = pr_info.body or ""
        linked_issues = self._find_issues_for_pr(pr_body)
        if linked_issues:
            issues_details = []
            for issue_num in linked_issues:
                try:
                    issue = self._client.get_issue(owner, repo_name, issue_num)
                    issue_comments = self._client.get_issue_comments(owner, repo_name, issue_num)
                    comments_list = "\n".join([
                        f"  - @{c.user.login} ({c.created_at}): {c.body}"
                        for c in issue_comments
                    ]) if issue_comments else "  No comments yet."

                    issues_details.append(
                        f"### Connected Issue #{issue_num}: {issue.title}\n"
                        f"Author: @{issue.user.login} (created {issue.created_at})\n"
                        f"Description:\n{issue.body or 'No description'}\n"
                        f"Discussion:\n{comments_list}"
                    )
                except Exception as e:
                    logger.warning(f"Could not fetch connected issue #{issue_num}: {e}")
            if issues_details:
                connected_issues_ctx = "\n---\n\n## 📋 CONNECTED ISSUE CONTEXT\n" + "\n\n".join(issues_details)

        workspace = WorkspaceManager()
        repo_path = workspace.get_repo_path(repo_full_name)
        pr_head_branch: str = pr_info.head.get('ref', 'unknown') if pr_info.head else "unknown"
        pr_base_branch: str = pr_info.base.get('ref', 'unknown') if pr_info.base else "unknown"
        pr_state: str = pr_info.state
        pr_created: str = pr_info.created_at or "unknown"

        # Dynamically determine instructions based on ownership/comments
        is_fixing_pr = is_own_pr or any(r.get("state") == "REQUEST_CHANGES" for r in reviews)

        if is_fixing_pr:
            instructions = (
                f"   Note: The repository is located locally at '{repo_path}'. This repository directory is your current working directory (cwd). You can verify this via the `get_working_directory` tool.\n"
                f"   Your task is to FIX/UPDATE this PR by addressing comments/change requests.\n"
                f"   DO NOT create a new branch or PR. Follow this exact workflow:\n"
                f"   1. Checkout the PR's head branch: `git checkout {pr_head_branch}`\n"
                f"   2. Implement the requested fixes or changes on this branch.\n"
                f"   3. Verify your fixes and run verification/tests.\n"
                f"   4. Commit and push the changes directly: `git add <files> && git commit -m \"fix: address feedback\" && git push origin {pr_head_branch}`\n"
                f"   5. After pushing, comment on the PR (using the `add_comment` tool) with a summary of the fixes implemented."
            )
        else:
            instructions = (
                f"   Note: The repository is located locally at '{repo_path}'. This repository directory is your current working directory (cwd). You can verify this via the `get_working_directory` tool.\n"
                "   CRITICAL: You are ONLY reviewing this PR. DO NOT edit files, DO NOT make commits, DO NOT push branches, and DO NOT create any new PRs.\n"
                "1. Read the PR diff carefully.\n"
                "2. Analyze the changes for correctness, quality, and potential issues.\n"
                "3. Check for: code quality, security issues, edge cases, test coverage.\n"
                "4. If the PR is good: approve it (using approve_pull_request tool) with a meaningful comment.\n"
                "5. If the PR has issues: request changes (using request_changes tool) with specific feedback.\n"
                "6. Post your review comment on the PR (using add_comment tool).\n"
                "IMPORTANT: Never merge the PR yourself - that is handled by humans."
            )

        return (
            f"Your mission is to process PR #{pr_number} in {repo_full_name}.\n\n"
            f"PR: {pr_info.title}\n"
            f"Author: @{pr_author}\n"
            f"Branch: {pr_head_branch} → {pr_base_branch}\n"
            f"State: {pr_state} (created {pr_created})\n\n"
            f"Description:\n{pr_info.body or 'No description'}\n\n"
            f"Files Changed ({len(pr_files)}):\n{files_summary}\n\n"
            f"Timeline Comments:\n{comments_str}\n\n"
            f"Reviews:\n{reviews_str}\n\n"
            f"{connected_issues_ctx}\n\n"
            "BEFORE MAKING ANY CHANGES:\n"
            "  - Search online for any technology, API, or behavior you are not 100% certain about.\n"
            "  - Read ALL review comments and change requests carefully.\n"
            "  - If any review comment is ambiguous or unclear:\n"
            "    → Post a clarifying comment on the PR (using the `add_comment` tool) with your specific question(s).\n"
            "    → End the comment with the marker: <!-- agent:awaiting-reply --> on its own line.\n"
            "    → STOP. Do NOT implement anything until a human replies. The system will re-dispatch you once a human responds.\n"
            "  - Never assume or guess what a reviewer meant. Always prefer asking over guessing.\n\n"
            f"Instructions:\n{instructions}"
        )