#!/usr/bin/env python3
"""
Multi-Agent Pipeline

Demonstrates a CI/CD-like pipeline with multiple specialized agents:
- Coder Agent: Implements features
- Reviewer Agent: Reviews code
- Tester Agent: Runs tests
- Deployer Agent: Deploys to staging

Each agent monitors for issues in their stage and advances them through the pipeline.

Usage:
    export GITEA_URL=https://gitea.example.com
    export GITEA_TOKEN=your-token
    export GITEA_OWNER=your-org
    export GITEA_REPO=your-repo

    # Run all agents in parallel (in separate terminals)
    python multi_agent_pipeline.py --agent=coder
    python multi_agent_pipeline.py --agent=reviewer
    python multi_agent_pipeline.py --agent=tester
    python multi_agent_pipeline.py --agent=deployer

    # Or run in round-robin mode (all agents in one process)
    python multi_agent_pipeline.py --mode=roundrobin
"""

import os
import sys
import time
import argparse
from datetime import datetime, timezone
from pathlib import Path
from typing import List

sys.path.insert(0, str(Path(__file__).parent.parent.parent))

from issue_tracker.backends.gitea import GiteaBackend
from issue_tracker.core.models import Issue, Label, User, Comment, IssueState
from issue_tracker.core.interfaces import IssueFilter


class BaseAgent:
    """Base class for pipeline agents."""

    def __init__(self, agent_id: str, role: str):
        self.agent_id = agent_id
        self.role = role
        self.backend = None

    def connect(self):
        """Connect to backend from environment."""
        base_url = os.environ['GITEA_URL']
        token = os.environ['GITEA_TOKEN']
        owner = os.environ['GITEA_OWNER']
        repo = os.environ['GITEA_REPO']

        self.backend = GiteaBackend()
        self.backend.connect({
            'base_url': base_url,
            'token': token,
            'owner': owner,
            'repo': repo
        })
        print(f"✓ {self.role} connected")

    def log(self, message: str):
        """Log a message with agent role prefix."""
        print(f"[{self.role}] {message}")

    def add_comment(self, issue: Issue, message: str):
        """Add a comment to an issue."""
        comment = Comment(
            id=None,
            body=f"**{self.role}**: {message}",
            author=User(id=self.agent_id, username=self.agent_id),
            created_at=datetime.now(timezone.utc)
        )
        self.backend.add_comment(issue.id, comment)

    def process_one(self) -> bool:
        """Process one issue. Return True if work was done."""
        raise NotImplementedError


class CoderAgent(BaseAgent):
    """Agent that implements features."""

    def __init__(self):
        super().__init__("agent-coder", "Coder")

    def process_one(self) -> bool:
        # Find issues needing implementation
        issues = self.backend.list_issues(IssueFilter(
            state='open',
            labels=['needs-implementation']
        ))

        if not issues:
            return False

        issue = issues[0]
        self.log(f"Implementing #{issue.number}: {issue.title}")

        # Update state
        issue.state = IssueState.IN_PROGRESS
        if not issue.assignees:
            issue.assignees = [User(id=self.agent_id, username=self.agent_id)]

        # Remove old label, add new label
        issue.labels = [l for l in issue.labels if l.name != 'needs-implementation']
        issue.labels.append(Label(name='needs-review'))

        self.backend.update_issue(issue)

        # Simulate work
        time.sleep(2)

        # Add comment
        self.add_comment(issue,
            "Implementation complete.\n\n"
            "**Files changed:**\n"
            "- src/feature.py\n"
            "- tests/test_feature.py\n\n"
            "Ready for code review."
        )

        self.log(f"✓ Completed #{issue.number}")
        return True


class ReviewerAgent(BaseAgent):
    """Agent that reviews code."""

    def __init__(self):
        super().__init__("agent-reviewer", "Reviewer")

    def process_one(self) -> bool:
        # Find issues needing review
        issues = self.backend.list_issues(IssueFilter(
            state='in_progress',
            labels=['needs-review']
        ))

        if not issues:
            return False

        issue = issues[0]
        self.log(f"Reviewing #{issue.number}: {issue.title}")

        # Simulate review
        time.sleep(2)

        # Update labels
        issue.labels = [l for l in issue.labels if l.name != 'needs-review']
        issue.labels.append(Label(name='needs-testing'))
        self.backend.update_issue(issue)

        # Add review comment
        self.add_comment(issue,
            "Code review complete. ✅\n\n"
            "**Review notes:**\n"
            "- Code quality: Good\n"
            "- Test coverage: 95%\n"
            "- Documentation: Complete\n\n"
            "Approved for testing."
        )

        self.log(f"✓ Approved #{issue.number}")
        return True


class TesterAgent(BaseAgent):
    """Agent that runs tests."""

    def __init__(self):
        super().__init__("agent-tester", "Tester")

    def process_one(self) -> bool:
        # Find issues needing testing
        issues = self.backend.list_issues(IssueFilter(
            state='in_progress',
            labels=['needs-testing']
        ))

        if not issues:
            return False

        issue = issues[0]
        self.log(f"Testing #{issue.number}: {issue.title}")

        # Simulate tests
        time.sleep(2)

        # Update labels
        issue.labels = [l for l in issue.labels if l.name != 'needs-testing']
        issue.labels.append(Label(name='needs-deployment'))
        self.backend.update_issue(issue)

        # Add test results
        self.add_comment(issue,
            "All tests passing. ✅\n\n"
            "**Test results:**\n"
            "- Unit tests: 50/50 passed\n"
            "- Integration tests: 12/12 passed\n"
            "- Coverage: 96.5%\n\n"
            "Ready for deployment."
        )

        self.log(f"✓ Tests passed #{issue.number}")
        return True


class DeployerAgent(BaseAgent):
    """Agent that deploys to staging."""

    def __init__(self):
        super().__init__("agent-deployer", "Deployer")

    def process_one(self) -> bool:
        # Find issues needing deployment
        issues = self.backend.list_issues(IssueFilter(
            state='in_progress',
            labels=['needs-deployment']
        ))

        if not issues:
            return False

        issue = issues[0]
        self.log(f"Deploying #{issue.number}: {issue.title}")

        # Simulate deployment
        time.sleep(2)

        # Close issue
        issue.state = IssueState.CLOSED
        issue.closed_at = datetime.now(timezone.utc)
        issue.labels = [l for l in issue.labels if l.name != 'needs-deployment']
        issue.labels.append(Label(name='deployed'))

        self.backend.update_issue(issue)

        # Add deployment comment
        self.add_comment(issue,
            "Deployed to staging. 🚀\n\n"
            "**Deployment info:**\n"
            "- Environment: staging\n"
            "- Version: v1.2.3\n"
            "- Status: Healthy\n\n"
            "Feature is live and ready for user testing."
        )

        self.log(f"✓ Deployed #{issue.number}")
        return True


def run_single_agent(agent: BaseAgent, poll_interval: int = 5):
    """Run a single agent in a loop."""
    agent.connect()
    agent.log("Starting pipeline agent...")
    agent.log("Press Ctrl+C to stop\n")

    while True:
        try:
            if agent.process_one():
                agent.log("Task completed, checking for more work...")
            else:
                agent.log(f"No work available, waiting {poll_interval}s...")
                time.sleep(poll_interval)
        except KeyboardInterrupt:
            agent.log("Shutting down...")
            break
        except Exception as e:
            agent.log(f"Error: {e}")
            time.sleep(poll_interval)


def run_roundrobin(agents: List[BaseAgent], poll_interval: int = 5):
    """Run all agents in round-robin fashion."""
    print("🤖 Starting multi-agent pipeline (round-robin mode)")
    print("   Agents:", ", ".join([a.role for a in agents]))
    print("   Press Ctrl+C to stop\n")

    # Connect all agents
    for agent in agents:
        agent.connect()

    while True:
        try:
            work_done = False
            for agent in agents:
                if agent.process_one():
                    work_done = True
                    time.sleep(1)  # Brief pause between agents

            if not work_done:
                print(f"⏸️  No work available for any agent, waiting {poll_interval}s...")
                time.sleep(poll_interval)

        except KeyboardInterrupt:
            print("\n\n⚠️  Shutting down all agents...")
            break
        except Exception as e:
            print(f"❌ Error: {e}")
            time.sleep(poll_interval)


def main():
    """Main entry point."""
    parser = argparse.ArgumentParser(description='Multi-agent pipeline')
    parser.add_argument('--agent', choices=['coder', 'reviewer', 'tester', 'deployer'],
                       help='Run specific agent')
    parser.add_argument('--mode', choices=['single', 'roundrobin'], default='single',
                       help='Execution mode')
    parser.add_argument('--poll-interval', type=int, default=5,
                       help='Polling interval in seconds')

    args = parser.parse_args()

    try:
        if args.mode == 'roundrobin':
            agents = [
                CoderAgent(),
                ReviewerAgent(),
                TesterAgent(),
                DeployerAgent()
            ]
            run_roundrobin(agents, args.poll_interval)
        else:
            if not args.agent:
                print("Error: --agent required in single mode")
                print("Use --mode=roundrobin to run all agents")
                sys.exit(1)

            agent_map = {
                'coder': CoderAgent(),
                'reviewer': ReviewerAgent(),
                'tester': TesterAgent(),
                'deployer': DeployerAgent()
            }

            agent = agent_map[args.agent]
            run_single_agent(agent, args.poll_interval)

    except KeyboardInterrupt:
        print("\n\n⚠️  Interrupted by user")
        sys.exit(0)
    except Exception as e:
        print(f"\n❌ Error: {e}")
        import traceback
        traceback.print_exc()
        sys.exit(1)


if __name__ == '__main__':
    main()