"""Declared portable graph planning, publication, and receipt-only status."""

from __future__ import annotations

import fcntl
import json
import os
from collections.abc import Callable, Generator
from contextlib import contextmanager
from pathlib import Path
from typing import cast

from ._fs_safety import (
    atomic_replace_bytes_at,
    open_confined_directory,
    read_bounded_file_at,
    require_bound_directory,
    safe_file_identity_at,
)
from .errors import DocForgeError
from .graph_projection import (
    GraphViewRequestV1,
    build_graph_projection_package,
    build_graph_view_plan,
)
from .models import (
    GenerationRecordingProject,
    GraphRenderConfig,
    GraphRenderView,
    IncrementalStateProject,
    ProjectService,
    ProjectSnapshot,
    ProjectState,
)
from .project import project_root_fingerprint
from .projection_contract import GraphViewPlanV1, ProjectionReceiptV1, projection_hash

GRAPH_RENDERER_ID = "portable_graph_html"
GRAPH_RENDERER_VERSION = "1"
GRAPH_PUBLICATION_MANIFEST_VERSION = 1
GRAPH_PUBLICATION_CONTRACT = "docforge.graph-publication"
MAX_GRAPH_PUBLICATION_BYTES = 256_000


class GraphRenderService:
    """Publish one declared artifact while keeping planning and rendering independent."""

    def __init__(self, project: ProjectService, *, allow_logic: bool = False) -> None:
        self.project = project
        self.allow_logic = allow_logic

    def plan(self, view_id: str) -> dict[str, object]:
        snapshot = self.project.load()
        view = self._view(self._config(snapshot), view_id)
        plan = self._plan(snapshot, view)
        return {
            "status": "ok",
            **self._identity(snapshot),
            "view_id": view.view_id,
            "plan": plan.as_dict(),
        }

    def status(self, view_id: str | None = None) -> dict[str, object]:
        config = self.project.descriptor.graph_render
        current = self._current_state()
        if config is None:
            return self._status_result(
                current,
                configured=False,
                state="not_configured",
                outputs=[],
            )
        views = config.views if view_id is None else (self._view(config, view_id),)
        first_outputs = [self._manifest_status(view, current) for view in views]
        outputs = [self._manifest_status(view, current) for view in views]
        if outputs != first_outputs:
            for output in outputs:
                if output["state"] == "current":
                    output["state"] = "stale"
                    output["reason"] = "publication_changed_during_status"
        final = self._current_state()
        if final != current:
            for output in outputs:
                if output["state"] == "current":
                    output["state"] = "stale"
                    output["reason"] = "source_changed_during_status"
        identity = final if final is not None else current
        return self._status_result(
            identity,
            configured=True,
            state="current" if all(item["state"] == "current" for item in outputs) else "stale",
            outputs=outputs,
        )

    def render(self, view_id: str) -> dict[str, object]:
        with self._lock():
            current_status = self.status(view_id)
            current_outputs = cast(list[dict[str, object]], current_status["outputs"])
            if current_status["state"] == "current" and current_outputs:
                return {
                    **current_status,
                    "publication": "unchanged",
                    "output": current_outputs[0],
                }
            snapshot = self.project.load()
            view = self._view(self._config(snapshot), view_id)
            plan = self._plan(snapshot, view)
            package = build_graph_projection_package(
                plan,
                renderer_id=GRAPH_RENDERER_ID,
                renderer_version=GRAPH_RENDERER_VERSION,
                max_output_bytes=snapshot.descriptor.limits.max_render_bytes,
            )
            from docforge_renderers.graph import PortableGraphHtmlRenderer

            result = PortableGraphHtmlRenderer().render(package)
            if len(result.artifacts) != 1:
                raise DocForgeError(
                    "invalid_projection",
                    "Portable graph renderer returned an unsupported artifact set",
                )
            artifact = result.artifacts[0]

            def verify() -> None:
                current = self.project.load()
                if (
                    current.revision != snapshot.revision
                    or current.source_hash != snapshot.source_hash
                ):
                    raise DocForgeError(
                        "render_input_changed",
                        "Canonical input changed during portable graph rendering",
                    )

            verify()
            if isinstance(self.project, GenerationRecordingProject):
                self.project.record_generation(snapshot)
            artifact_evidence = artifact.evidence()
            try:
                store_identity = self._publish_artifact(
                    snapshot,
                    artifact_evidence["sha256"],
                    artifact.content,
                    verify=verify,
                )
            except DocForgeError as error:
                if self._mutation_committed(error):
                    return self._degraded_publication(
                        snapshot,
                        view,
                        plan,
                        package.package_id,
                        result.receipt.as_dict(),
                        artifact_evidence,
                        stage="artifact_store",
                        error=error,
                        output_published=False,
                    )
                raise
            try:
                output_identity = self._publish_output(
                    snapshot,
                    view,
                    artifact.content,
                    verify=verify,
                )
            except DocForgeError as error:
                if self._mutation_committed(error):
                    return self._degraded_publication(
                        snapshot,
                        view,
                        plan,
                        package.package_id,
                        result.receipt.as_dict(),
                        artifact_evidence,
                        stage="output",
                        error=error,
                        output_published=True,
                    )
                raise
            manifest = self._manifest(
                snapshot,
                view,
                plan,
                package.package_id,
                result.receipt.as_dict(),
                artifact_evidence,
                store_identity,
                output_identity,
            )
            try:
                self._publish_manifest(snapshot, view, manifest, verify=verify)
            except DocForgeError as error:
                return self._degraded_publication(
                    snapshot,
                    view,
                    plan,
                    package.package_id,
                    result.receipt.as_dict(),
                    artifact_evidence,
                    stage="manifest",
                    error=error,
                    output_published=True,
                )
            return {
                "status": "ok",
                **self._identity(snapshot),
                "view_id": view.view_id,
                "state": "current",
                "publication": "published",
                "plan_id": plan.plan_id,
                "package_id": package.package_id,
                "output": {
                    **artifact.evidence(),
                    "path": view.output_path.relative_to(snapshot.descriptor.root).as_posix(),
                },
                "receipt": result.receipt.as_dict(),
                "manifest": {
                    "state": "current",
                    "publication_id": manifest["publication_id"],
                },
            }

    @staticmethod
    def _mutation_committed(error: DocForgeError) -> bool:
        return error.details.get("mutation_committed") is True

    def _degraded_publication(
        self,
        snapshot: ProjectSnapshot,
        view: GraphRenderView,
        plan: GraphViewPlanV1,
        package_id: str,
        receipt: dict[str, object],
        artifact: dict[str, object],
        *,
        stage: str,
        error: DocForgeError,
        output_published: bool,
    ) -> dict[str, object]:
        return {
            "status": "ok",
            **self._identity(snapshot),
            "view_id": view.view_id,
            "state": "degraded",
            "publication": "published" if output_published else "partial",
            "committed_stage": stage,
            "plan_id": plan.plan_id,
            "package_id": package_id,
            "artifact": artifact,
            "output": {
                **artifact,
                "path": view.output_path.relative_to(snapshot.descriptor.root).as_posix(),
                "state": "unverified" if output_published else "not_published",
            },
            "receipt": receipt,
            "manifest": {
                "state": "failed",
                "error": error.as_dict(),
            },
        }

    def _manifest_status(
        self,
        view: GraphRenderView,
        current: ProjectState | None,
    ) -> dict[str, object]:
        manifest = self._read_manifest(view)
        base = {
            "view_id": view.view_id,
            "renderer": GRAPH_RENDERER_ID,
            "renderer_version": GRAPH_RENDERER_VERSION,
            "path": view.output_path.relative_to(self.project.descriptor.root).as_posix(),
            "verification": "manifest",
        }
        if manifest is None:
            return {**base, "state": "missing", "reason": "manifest_missing"}
        if not self._valid_manifest(view, manifest):
            return {**base, "state": "unverified", "reason": "manifest_invalid"}
        if current is None:
            reason = (
                "source_generation_changed"
                if isinstance(self.project, GenerationRecordingProject)
                else "source_generation_unavailable"
            )
            return {
                **base,
                "state": (
                    "stale"
                    if isinstance(self.project, GenerationRecordingProject)
                    else "unverified"
                ),
                "reason": reason,
                "plan_id": manifest.get("plan_id"),
                "package_id": manifest.get("package_id"),
            }
        project = cast(dict[str, object], manifest["project"])
        if project["revision"] != current.revision or project["source_hash"] != current.source_hash:
            return {
                **base,
                "state": "stale",
                "reason": "source_generation_changed",
                "plan_id": manifest["plan_id"],
                "package_id": manifest["package_id"],
            }
        artifact = cast(dict[str, object], manifest["artifact"])
        store = cast(dict[str, object], manifest["store"])
        artifact_root = self.project.descriptor.cache_root / "projection-artifacts"
        if not artifact_root.exists():
            return {
                **base,
                "state": "stale",
                "reason": "artifact_store_missing",
                "plan_id": manifest["plan_id"],
                "package_id": manifest["package_id"],
            }
        if artifact_root.is_symlink() or not artifact_root.is_dir():
            return {
                **base,
                "state": "unsafe",
                "reason": "artifact_store_unsafe",
                "plan_id": manifest["plan_id"],
                "package_id": manifest["package_id"],
            }
        artifact_directory: int | None = None
        try:
            artifact_directory = open_confined_directory(
                self.project.descriptor.root,
                artifact_root,
                create=False,
            )
            artifact_identity = safe_file_identity_at(
                artifact_root,
                artifact_directory,
                f"{artifact['sha256']}.html",
            )
        except DocForgeError:
            return {
                **base,
                "state": "unsafe",
                "reason": "artifact_store_unsafe",
                "plan_id": manifest["plan_id"],
                "package_id": manifest["package_id"],
            }
        finally:
            if artifact_directory is not None:
                os.close(artifact_directory)
        if artifact_identity is None:
            return {
                **base,
                "state": "stale",
                "reason": "artifact_store_missing",
                "plan_id": manifest["plan_id"],
                "package_id": manifest["package_id"],
            }
        if artifact_identity != store:
            return {
                **base,
                "state": "stale",
                "reason": "artifact_store_changed",
                "plan_id": manifest["plan_id"],
                "package_id": manifest["package_id"],
            }
        try:
            directory = open_confined_directory(
                self.project.descriptor.root,
                view.output_path.parent,
                create=False,
            )
        except DocForgeError:
            return {**base, "state": "unsafe", "reason": "output_root_unsafe"}
        try:
            identity = safe_file_identity_at(
                view.output_path.parent, directory, view.output_path.name
            )
        except DocForgeError:
            return {**base, "state": "unsafe", "reason": "output_unsafe"}
        finally:
            os.close(directory)
        expected = cast(dict[str, object], manifest["output"])
        if identity != expected:
            return {
                **base,
                "state": "stale",
                "reason": "output_changed",
                "plan_id": manifest["plan_id"],
                "package_id": manifest["package_id"],
            }
        return {
            **base,
            "state": "current",
            "reason": None,
            "plan_id": manifest["plan_id"],
            "package_id": manifest["package_id"],
            "publication_id": manifest["publication_id"],
            "artifact": manifest["artifact"],
        }

    def _read_manifest(self, view: GraphRenderView) -> dict[str, object] | None:
        root = self._manifest_root()
        if not root.is_dir() or root.is_symlink():
            return None
        try:
            descriptor = open_confined_directory(
                self.project.descriptor.root,
                root,
                create=False,
            )
        except DocForgeError:
            return None
        try:
            raw = read_bounded_file_at(
                descriptor,
                f"{view.view_id}.json",
                MAX_GRAPH_PUBLICATION_BYTES,
            )
        except DocForgeError:
            return None
        finally:
            os.close(descriptor)
        if raw is None:
            return None
        try:
            value: object = json.loads(raw)
        except (UnicodeDecodeError, json.JSONDecodeError):
            return None
        return cast(dict[str, object], value) if isinstance(value, dict) else None

    def _valid_manifest(self, view: GraphRenderView, manifest: dict[str, object]) -> bool:
        required = {
            "schema_version",
            "contract",
            "publication_id",
            "project",
            "view_id",
            "view_config_hash",
            "plan_id",
            "package_id",
            "renderer",
            "receipt",
            "artifact",
            "store",
            "output",
        }
        try:
            if (
                set(manifest) != required
                or manifest.get("schema_version") != GRAPH_PUBLICATION_MANIFEST_VERSION
                or manifest.get("contract") != GRAPH_PUBLICATION_CONTRACT
                or manifest.get("view_id") != view.view_id
                or manifest.get("view_config_hash") != self._view_hash(view)
                or not self._hash(manifest.get("plan_id"))
                or not self._hash(manifest.get("package_id"))
            ):
                return False
            project = manifest.get("project")
            descriptor = self.project.descriptor
            if not isinstance(project, dict):
                return False
            project_document = cast(dict[str, object], project)
            if (
                set(project_document)
                != {
                    "project_id",
                    "project_root_fingerprint",
                    "adapter",
                    "revision",
                    "source_hash",
                }
                or project_document.get("project_id") != descriptor.project_id
                or project_document.get("project_root_fingerprint")
                != project_root_fingerprint(descriptor.root)
                or project_document.get("adapter") != descriptor.adapter
                or not isinstance(project_document.get("revision"), str)
                or not project_document["revision"]
                or not self._hash(project_document.get("source_hash"))
            ):
                return False
            renderer = manifest.get("renderer")
            if renderer != {
                "renderer_id": GRAPH_RENDERER_ID,
                "renderer_version": GRAPH_RENDERER_VERSION,
            }:
                return False
            receipt_value = manifest.get("receipt")
            if not isinstance(receipt_value, dict):
                return False
            receipt = ProjectionReceiptV1.from_dict(
                dict(cast(dict[str, object], receipt_value))
            ).as_dict()
            artifacts = receipt.get("artifacts")
            if not isinstance(artifacts, list):
                return False
            artifact_values = cast(list[object], artifacts)
            if (
                receipt.get("kind") != "graph"
                or receipt.get("plan_id") != manifest["plan_id"]
                or receipt.get("package_id") != manifest["package_id"]
                or receipt.get("renderer") != renderer
                or len(artifact_values) != 1
                or manifest.get("artifact") != artifact_values[0]
            ):
                return False
            artifact = artifact_values[0]
            if not isinstance(artifact, dict):
                return False
            artifact_document = cast(dict[str, object], artifact)
            if (
                artifact_document.get("artifact_id") != "portable-graph.html"
                or artifact_document.get("media_type") != "text/html; charset=utf-8"
            ):
                return False
            artifact_hash = artifact_document.get("sha256")
            artifact_bytes = artifact_document.get("bytes")
            store = manifest.get("store")
            output = manifest.get("output")
            if (
                not self._file_identity(store, expected_name=f"{artifact_hash}.html")
                or not self._file_identity(output, expected_name=view.output_path.name)
                or type(artifact_bytes) is not int
                or cast(dict[str, object], store)["size"] != artifact_bytes
                or cast(dict[str, object], output)["size"] != artifact_bytes
            ):
                return False
            body = dict(manifest)
            publication_id = body.pop("publication_id", None)
            return self._hash(publication_id) and publication_id == projection_hash(body)
        except (DocForgeError, KeyError, TypeError, ValueError):
            return False

    @staticmethod
    def _hash(value: object) -> bool:
        return (
            isinstance(value, str)
            and len(value) == 64
            and all(character in "0123456789abcdef" for character in value)
        )

    @staticmethod
    def _file_identity(value: object, *, expected_name: str) -> bool:
        if not isinstance(value, dict):
            return False
        document = cast(dict[str, object], value)
        required = {"path", "device", "inode", "mode", "size", "mtime_ns", "ctime_ns"}
        return (
            set(document) == required
            and document.get("path") == expected_name
            and all(
                type(document.get(field)) is int and cast(int, document[field]) >= 0
                for field in required - {"path"}
            )
        )

    def _manifest(
        self,
        snapshot: ProjectSnapshot,
        view: GraphRenderView,
        plan: GraphViewPlanV1,
        package_id: str,
        receipt: dict[str, object],
        artifact: dict[str, object],
        store: dict[str, object],
        output: dict[str, object],
    ) -> dict[str, object]:
        body: dict[str, object] = {
            "schema_version": GRAPH_PUBLICATION_MANIFEST_VERSION,
            "contract": GRAPH_PUBLICATION_CONTRACT,
            "project": self._identity(snapshot),
            "view_id": view.view_id,
            "view_config_hash": self._view_hash(view),
            "plan_id": plan.plan_id,
            "package_id": package_id,
            "renderer": {
                "renderer_id": GRAPH_RENDERER_ID,
                "renderer_version": GRAPH_RENDERER_VERSION,
            },
            "receipt": receipt,
            "artifact": artifact,
            "store": store,
            "output": output,
        }
        return {**body, "publication_id": projection_hash(body)}

    def _publish_artifact(
        self,
        snapshot: ProjectSnapshot,
        artifact_hash: object,
        content: bytes,
        *,
        verify: Callable[[], None],
    ) -> dict[str, object]:
        if not isinstance(artifact_hash, str):
            raise DocForgeError("invalid_projection", "Artifact hash is invalid")
        root = snapshot.descriptor.cache_root / "projection-artifacts"
        descriptor = open_confined_directory(snapshot.descriptor.root, root, create=True)
        name = f"{artifact_hash}.html"
        try:
            try:
                existing = read_bounded_file_at(descriptor, name, len(content))
            except DocForgeError as error:
                if error.code != "invalid_projection":
                    raise
                existing = None
            if existing == content:
                identity = safe_file_identity_at(root, descriptor, name)
                assert identity is not None
                return identity
            return atomic_replace_bytes_at(root, descriptor, name, content, verify=verify)
        finally:
            os.close(descriptor)

    def _publish_output(
        self,
        snapshot: ProjectSnapshot,
        view: GraphRenderView,
        content: bytes,
        *,
        verify: Callable[[], None],
    ) -> dict[str, object]:
        root = view.output_path.parent
        descriptor = open_confined_directory(snapshot.descriptor.root, root, create=True)
        try:
            try:
                existing = read_bounded_file_at(
                    descriptor,
                    view.output_path.name,
                    len(content),
                )
            except DocForgeError as error:
                if error.code != "invalid_projection":
                    raise
                existing = None
            if existing == content:
                identity = safe_file_identity_at(root, descriptor, view.output_path.name)
                assert identity is not None
                return identity
            return atomic_replace_bytes_at(
                root,
                descriptor,
                view.output_path.name,
                content,
                verify=verify,
            )
        finally:
            os.close(descriptor)

    def _publish_manifest(
        self,
        snapshot: ProjectSnapshot,
        view: GraphRenderView,
        manifest: dict[str, object],
        *,
        verify: Callable[[], None],
    ) -> None:
        raw = json.dumps(manifest, sort_keys=True, indent=2).encode() + b"\n"
        if len(raw) > MAX_GRAPH_PUBLICATION_BYTES:
            raise DocForgeError(
                "projection_too_large",
                "Portable graph publication manifest exceeds its fixed limit",
            )
        root = self._manifest_root()
        descriptor = open_confined_directory(snapshot.descriptor.root, root, create=True)
        try:
            atomic_replace_bytes_at(
                root,
                descriptor,
                f"{view.view_id}.json",
                raw,
                verify=verify,
            )
        finally:
            os.close(descriptor)

    @contextmanager
    def _lock(self) -> Generator[None]:
        root = self.project.descriptor.cache_root
        descriptor = open_confined_directory(self.project.descriptor.root, root, create=True)
        lock_descriptor: int | None = None
        try:
            lock_descriptor = os.open(
                "graph-render.lock",
                os.O_RDWR | os.O_CREAT | os.O_NOFOLLOW,
                0o600,
                dir_fd=descriptor,
            )
            fcntl.flock(lock_descriptor, fcntl.LOCK_EX)
            require_bound_directory(root, descriptor)
            yield
        except OSError as error:
            raise DocForgeError(
                "publication_failure",
                "Portable graph render lock is unavailable",
            ) from error
        finally:
            if lock_descriptor is not None:
                os.close(lock_descriptor)
            os.close(descriptor)

    def _plan(self, snapshot: ProjectSnapshot, view: GraphRenderView) -> GraphViewPlanV1:
        return build_graph_view_plan(
            snapshot,
            GraphViewRequestV1(
                view_id=view.view_id,
                title=view.title,
                root_node_id=view.root_node_id,
                query=view.query,
                initial_mode=view.initial_mode,
                depth=view.depth,
                max_nodes=view.max_nodes,
                max_edges=view.max_edges,
                max_work=view.max_work,
                families=view.families,
                relations=view.relations,
                authorities=view.authorities,
                statuses=view.statuses,
                tags=view.tags,
                include_logic=view.include_logic,
            ),
            self.allow_logic,
        )

    def _current_state(self) -> ProjectState | None:
        if isinstance(self.project, IncrementalStateProject):
            return self.project.incremental_state()
        return None

    def _config(self, snapshot: ProjectSnapshot) -> GraphRenderConfig:
        config = snapshot.descriptor.graph_render
        if config is None:
            raise DocForgeError(
                "graph_render_not_configured",
                "Project has no portable graph render configuration",
            )
        return config

    @staticmethod
    def _view(config: GraphRenderConfig, view_id: str) -> GraphRenderView:
        for view in config.views:
            if view.view_id == view_id:
                return view
        raise DocForgeError(
            "unknown_graph_render_view",
            "Portable graph view is not declared",
            view_id=view_id,
        )

    def _manifest_root(self) -> Path:
        return self.project.descriptor.cache_root / "projection-publications" / "graph"

    @staticmethod
    def _view_hash(view: GraphRenderView) -> str:
        return projection_hash(
            {
                "view_id": view.view_id,
                "renderer": view.renderer,
                "title": view.title,
                "root_node_id": view.root_node_id,
                "query": view.query,
                "initial_mode": view.initial_mode,
                "depth": view.depth,
                "max_nodes": view.max_nodes,
                "max_edges": view.max_edges,
                "max_work": view.max_work,
                "families": list(view.families),
                "relations": list(view.relations),
                "authorities": list(view.authorities),
                "statuses": list(view.statuses),
                "tags": list(view.tags),
                "include_logic": view.include_logic,
            }
        )

    def _status_result(self, current: ProjectState | None, **payload: object) -> dict[str, object]:
        descriptor = self.project.descriptor
        return {
            "status": "ok",
            "project_id": descriptor.project_id,
            "project_root_fingerprint": project_root_fingerprint(descriptor.root),
            "adapter": descriptor.adapter,
            "revision": current.revision if current is not None else "unknown",
            "source_hash": current.source_hash if current is not None else None,
            **payload,
        }

    @staticmethod
    def _identity(snapshot: ProjectSnapshot) -> dict[str, object]:
        return {
            "project_id": snapshot.descriptor.project_id,
            "project_root_fingerprint": project_root_fingerprint(snapshot.descriptor.root),
            "adapter": snapshot.descriptor.adapter,
            "revision": snapshot.revision,
            "source_hash": snapshot.source_hash,
        }