"""
Kin — structured deploy module.

Business logic for project deployments:
- Runtime-based step templates (docker/node/python/static)
- Local and SSH execution
- Dependency chain traversal via project_links
"""

import shlex
import sqlite3
import subprocess
import time

VALID_RUNTIMES = {"docker", "node", "python", "static"}

# Base command templates per runtime.
# deploy_restart_cmd (if set) is appended as the final step for all runtimes.
RUNTIME_STEPS = {
    "docker": ["git pull", "docker compose up -d --build"],
    "node": ["git pull", "npm install --production", "pm2 restart all"],
    "python": ["git pull", "pip install -r requirements.txt"],
    "static": ["git pull", "nginx -s reload"],
}


def build_deploy_steps(project: dict) -> list[str]:
    """Build deploy command list based on runtime and project config.

    Returns empty list if deploy_runtime is not set or invalid.
    Appends deploy_restart_cmd as the last step if provided.
    """
    runtime = project.get("deploy_runtime")
    if not runtime or runtime not in RUNTIME_STEPS:
        return []

    steps = list(RUNTIME_STEPS[runtime])

    restart_cmd = project.get("deploy_restart_cmd")
    if restart_cmd and restart_cmd.strip():
        steps.append(restart_cmd.strip())

    return steps


def _build_ssh_cmd(project: dict, command: str) -> list[str]:
    """Build SSH subprocess command list to run a shell command on deploy_host."""
    deploy_host = project.get("deploy_host") or project.get("ssh_host")
    ssh_user = project.get("ssh_user") or "root"
    ssh_key = project.get("ssh_key_path")
    proxy_jump = project.get("ssh_proxy_jump")
    deploy_path = project.get("deploy_path")

    full_cmd = f"cd {shlex.quote(deploy_path)} && {command}" if deploy_path else command

    cmd = ["ssh"]
    if ssh_key:
        cmd += ["-i", ssh_key]
    if proxy_jump:
        cmd += ["-J", proxy_jump]
    cmd += ["-o", "StrictHostKeyChecking=no", "-o", "BatchMode=yes"]
    cmd += [f"{ssh_user}@{deploy_host}", full_cmd]
    return cmd


def execute_deploy(project: dict, conn: sqlite3.Connection) -> dict:
    """Execute deploy steps for a project. Returns structured result.

    Returns:
        {
            "success": bool,
            "steps": list[str],
            "results": list[{"step", "stdout", "stderr", "exit_code"}],
        }
    """
    deploy_host = project.get("deploy_host") or project.get("ssh_host")
    steps = build_deploy_steps(project)

    if not steps:
        return {
            "success": False,
            "steps": [],
            "results": [],
            "error": "No deploy steps: deploy_runtime not set or invalid",
        }

    deploy_path = project.get("deploy_path") or project.get("path") or None
    results = []
    overall_success = True

    for step in steps:
        try:
            if deploy_host:
                cmd = _build_ssh_cmd(project, step)
                proc = subprocess.run(
                    cmd,
                    capture_output=True,
                    text=True,
                    timeout=120,
                )
            else:
                # WARNING: shell=True — deploy commands are admin-only, set by project owner
                proc = subprocess.run(
                    step,
                    shell=True,  # WARNING: shell=True — command is admin-only
                    cwd=deploy_path,
                    capture_output=True,
                    text=True,
                    timeout=120,
                )
        except subprocess.TimeoutExpired:
            results.append({
                "step": step,
                "stdout": "",
                "stderr": "Timed out after 120 seconds",
                "exit_code": -1,
            })
            overall_success = False
            break
        except Exception as e:
            results.append({
                "step": step,
                "stdout": "",
                "stderr": str(e),
                "exit_code": -1,
            })
            overall_success = False
            break

        results.append({
            "step": step,
            "stdout": proc.stdout,
            "stderr": proc.stderr,
            "exit_code": proc.returncode,
        })

        if proc.returncode != 0:
            overall_success = False
            break  # Stop on first failure

    return {
        "success": overall_success,
        "steps": steps,
        "results": results,
    }


def get_deploy_chain(conn: sqlite3.Connection, project_id: str) -> list[str]:
    """Get ordered deploy chain: project + all downstream dependents (BFS, cycle-safe).

    Traverses project_links where type='depends_on':
    - from_project depends_on to_project
    - When to_project changes, from_project must also be redeployed.

    Returns list starting with project_id, followed by dependents in BFS order.
    """
    visited: set[str] = {project_id}
    chain: list[str] = [project_id]
    queue: list[str] = [project_id]

    while queue:
        current = queue.pop(0)
        rows = conn.execute(
            "SELECT from_project FROM project_links"
            " WHERE to_project = ? AND type = 'depends_on'",
            (current,),
        ).fetchall()
        for row in rows:
            dep_id = row[0]
            if dep_id not in visited:
                visited.add(dep_id)
                chain.append(dep_id)
                queue.append(dep_id)

    return chain


def deploy_with_dependents(conn: sqlite3.Connection, project_id: str) -> dict:
    """Deploy project and all dependents in chain order.

    Returns:
        {
            "success": bool,
            "steps": list[str],            # main project steps
            "results": list[dict],          # main project step results
            "dependents_deployed": list[str],
        }
    """
    from core.models import get_project

    chain = get_deploy_chain(conn, project_id)
    dependents = [pid for pid in chain if pid != project_id]

    # Deploy main project first
    main_project = get_project(conn, project_id)
    if not main_project:
        return {
            "success": False,
            "steps": [],
            "results": [],
            "dependents_deployed": [],
            "error": f"Project '{project_id}' not found",
        }

    main_result = execute_deploy(main_project, conn)
    overall_success = main_result["success"]

    dependents_deployed = []
    if main_result["success"] and dependents:
        for dep_id in dependents:
            dep_project = get_project(conn, dep_id)
            if dep_project:
                dep_result = execute_deploy(dep_project, conn)
                if dep_result["success"]:
                    dependents_deployed.append(dep_id)
                else:
                    overall_success = False

    return {
        "success": overall_success,
        "steps": main_result.get("steps", []),
        "results": main_result.get("results", []),
        "dependents_deployed": dependents_deployed,
    }