import json

from flask import Blueprint, Response, redirect, render_template, request
from sqlalchemy import select

from l4d2web.auth import current_user, require_admin, require_login
from l4d2web.db import session_scope
from l4d2web.models import Blueprint as BlueprintModel
from l4d2web.models import (
    BlueprintOverlay,
    Job,
    Overlay,
    OverlayWorkshopItem,
    Server,
    User,
    WorkshopItem,
)
from l4d2web.services.overlay_files import (
    list_directory,
    safe_resolve_for_listing,
)


bp = Blueprint("pages", __name__)


@bp.get("/dashboard")
@require_login
def dashboard() -> str:
    return render_template("dashboard.html")


@bp.get("/admin")
@require_admin
def admin_home() -> str:
    return render_template("admin.html")


@bp.post("/admin/install")
@require_admin
def enqueue_runtime_install() -> Response:
    user = current_user()
    assert user is not None
    with session_scope() as db:
        db.add(Job(user_id=user.id, server_id=None, operation="install", state="queued"))
    return redirect("/admin/jobs")


@bp.get("/admin/users")
@require_admin
def admin_users() -> str:
    with session_scope() as db:
        users = db.scalars(select(User).order_by(User.username)).all()
    return render_template("admin_users.html", users=users)


@bp.get("/admin/jobs")
@require_admin
def admin_jobs() -> str:
    with session_scope() as db:
        rows = db.execute(
            select(Job, User, Server)
            .outerjoin(User, User.id == Job.user_id)
            .outerjoin(Server, Server.id == Job.server_id)
            .order_by(Job.created_at.desc())
        ).all()
    return render_template("admin_jobs.html", rows=rows)


@bp.get("/servers")
@require_login
def servers_page() -> str:
    user = current_user()
    assert user is not None
    with session_scope() as db:
        rows = db.execute(
            select(Server, BlueprintModel)
            .join(BlueprintModel, BlueprintModel.id == Server.blueprint_id)
            .where(Server.user_id == user.id)
            .order_by(Server.name)
        ).all()
        blueprints = db.scalars(
            select(BlueprintModel).where(BlueprintModel.user_id == user.id).order_by(BlueprintModel.name)
        ).all()

    prefill_blueprint_id: int | None = None
    raw_prefill = request.args.get("blueprint_id")
    if raw_prefill:
        try:
            candidate = int(raw_prefill)
        except ValueError:
            candidate = None
        if candidate is not None and any(b.id == candidate for b in blueprints):
            prefill_blueprint_id = candidate

    return render_template(
        "servers.html",
        rows=rows,
        blueprints=blueprints,
        prefill_blueprint_id=prefill_blueprint_id,
    )


@bp.get("/servers/<int:server_id>")
@require_login
def server_detail(server_id: int):
    user = current_user()
    assert user is not None

    with session_scope() as db:
        server = db.scalar(select(Server).where(Server.id == server_id, Server.user_id == user.id))
        if server is None:
            return Response(status=404)
        blueprint = db.scalar(select(BlueprintModel).where(BlueprintModel.id == server.blueprint_id))
        recent_job_rows = db.execute(
            select(Job, User, Server)
            .outerjoin(User, User.id == Job.user_id)
            .outerjoin(Server, Server.id == Job.server_id)
            .where(Job.server_id == server.id)
            .order_by(Job.created_at.desc())
            .limit(5)
        ).all()

    return render_template(
        "server_detail.html",
        server=server,
        blueprint=blueprint,
        recent_job_rows=recent_job_rows,
    )


@bp.get("/servers/<int:server_id>/jobs")
@require_login
def server_jobs_page(server_id: int):
    user = current_user()
    assert user is not None

    with session_scope() as db:
        server = db.scalar(select(Server).where(Server.id == server_id, Server.user_id == user.id))
        if server is None:
            return Response(status=404)
        rows = db.execute(
            select(Job, User, Server)
            .outerjoin(User, User.id == Job.user_id)
            .outerjoin(Server, Server.id == Job.server_id)
            .where(Job.server_id == server.id)
            .order_by(Job.created_at.desc())
        ).all()

    return render_template("server_jobs.html", server=server, rows=rows)


@bp.get("/overlays")
@require_login
def overlays() -> str:
    user = current_user()
    assert user is not None
    with session_scope() as db:
        query = select(Overlay).order_by(Overlay.name)
        if not user.admin:
            query = query.where(
                Overlay.user_id.is_(None) | (Overlay.user_id == user.id)
            )
        overlays = db.scalars(query).all()
    return render_template("overlays.html", overlays=overlays)


@bp.get("/overlays/<int:overlay_id>/jobs")
@require_login
def overlay_jobs_page(overlay_id: int):
    user = current_user()
    assert user is not None
    with session_scope() as db:
        overlay = db.scalar(select(Overlay).where(Overlay.id == overlay_id))
        if overlay is None:
            return Response(status=404)
        if not user.admin and overlay.user_id is not None and overlay.user_id != user.id:
            return Response(status=403)
        rows = db.execute(
            select(Job, User, Server)
            .outerjoin(User, User.id == Job.user_id)
            .outerjoin(Server, Server.id == Job.server_id)
            .where(Job.operation == "build_overlay", Job.overlay_id == overlay.id)
            .order_by(Job.created_at.desc())
        ).all()
    return render_template("overlay_jobs.html", overlay=overlay, rows=rows)


@bp.get("/overlays/<int:overlay_id>")
@require_login
def overlay_detail(overlay_id: int):
    user = current_user()
    assert user is not None
    with session_scope() as db:
        overlay = db.scalar(select(Overlay).where(Overlay.id == overlay_id))
        if overlay is None:
            return Response(status=404)
        if not user.admin and overlay.user_id is not None and overlay.user_id != user.id:
            return Response(status=403)
        using_blueprints_query = (
            select(BlueprintModel)
            .join(BlueprintOverlay, BlueprintOverlay.blueprint_id == BlueprintModel.id)
            .where(BlueprintOverlay.overlay_id == overlay.id)
            .order_by(BlueprintModel.name)
        )
        if not user.admin:
            using_blueprints_query = using_blueprints_query.where(BlueprintModel.user_id == user.id)
        using_blueprints = db.scalars(using_blueprints_query).all()
        workshop_items = []
        if overlay.type == "workshop":
            workshop_items = db.scalars(
                select(WorkshopItem)
                .join(
                    OverlayWorkshopItem,
                    OverlayWorkshopItem.workshop_item_id == WorkshopItem.id,
                )
                .where(OverlayWorkshopItem.overlay_id == overlay.id)
                .order_by(WorkshopItem.created_at)
            ).all()
        latest_build_job = db.scalar(
            select(Job)
            .where(Job.operation == "build_overlay", Job.overlay_id == overlay.id)
            .order_by(Job.created_at.desc())
            .limit(1)
        )

    file_tree_root_entries, file_tree_truncated_count = _root_file_tree(overlay)

    return render_template(
        "overlay_detail.html",
        overlay=overlay,
        using_blueprints=using_blueprints,
        workshop_items=workshop_items,
        latest_build_job=latest_build_job,
        file_tree_root_entries=file_tree_root_entries,
        file_tree_truncated=file_tree_truncated_count > 0
        if file_tree_root_entries is not None
        else False,
        file_tree_truncated_count=file_tree_truncated_count,
    )


def _root_file_tree(overlay: Overlay) -> tuple[list[dict] | None, int]:
    """Return (entries, truncated_count) for the overlay's runtime directory,
    or (None, 0) if the directory doesn't exist or the path is unresolvable
    (e.g. legacy absolute `overlay.path` values that pre-date the current
    `path == str(id)` convention)."""
    try:
        overlay_root = safe_resolve_for_listing(overlay.path, "")
    except ValueError:
        return None, 0
    if not overlay_root.is_dir():
        return None, 0
    entries, truncated_count = list_directory(overlay_root, overlay_root)
    return entries, truncated_count


@bp.get("/blueprints")
@require_login
def blueprints_page() -> str:
    user = current_user()
    assert user is not None
    with session_scope() as db:
        blueprints = db.scalars(
            select(BlueprintModel).where(BlueprintModel.user_id == user.id).order_by(BlueprintModel.name)
        ).all()
    return render_template("blueprints.html", blueprints=blueprints)


@bp.get("/blueprints/<int:blueprint_id>")
@require_login
def blueprint_page(blueprint_id: int):
    user = current_user()
    assert user is not None

    with session_scope() as db:
        blueprint = db.scalar(select(BlueprintModel).where(BlueprintModel.id == blueprint_id))
        if blueprint is None:
            return Response(status=404)
        if blueprint.user_id != user.id:
            return Response(status=403)

        selected_overlays = db.scalars(
            select(Overlay)
            .join(BlueprintOverlay, BlueprintOverlay.overlay_id == Overlay.id)
            .where(BlueprintOverlay.blueprint_id == blueprint.id)
            .order_by(BlueprintOverlay.position)
        ).all()
        position_rows = db.execute(
            select(BlueprintOverlay.overlay_id, BlueprintOverlay.position)
            .where(BlueprintOverlay.blueprint_id == blueprint.id)
        ).all()
        all_overlays = db.scalars(
            select(Overlay)
            .where(Overlay.user_id.is_(None) | (Overlay.user_id == user.id))
            .order_by(Overlay.name)
        ).all()

    overlay_positions = {overlay_id: position + 1 for overlay_id, position in position_rows}
    return render_template(
        "blueprint_detail.html",
        blueprint=blueprint,
        selected_overlays=selected_overlays,
        all_overlays=all_overlays,
        selected_overlay_ids={overlay.id for overlay in selected_overlays},
        overlay_positions=overlay_positions,
        arguments=json.loads(blueprint.arguments),
        config_lines=json.loads(blueprint.config),
    )