"""
Infospace configuration model and YAML loader.

An infospace is declared via an ``infospace.yaml`` file that specifies
its topic, disciplines, schemas, competency questions, and viability
thresholds.  This module provides the data models and I/O for that
configuration.

Example ``infospace.yaml``::

    topic:
      name: "The Wealth of Nations"
      domain: "Classical Economics"
      sources: artifacts/sources/

    disciplines:
      - name: "Viable System Model"
        path: artifacts/vsm-reference/

    schemas:
      entity: schemas/economic-entity-schema-v1.0.md

    competency_questions: schemas/competency-questions.md

    viability:
      coverage_ratio: { min: 0.60 }
      per_entity_mean: { min: 3.5 }
"""

from __future__ import annotations

from dataclasses import dataclass, field
from pathlib import Path
from typing import Any, Dict, List, Optional

import yaml


@dataclass
class TopicConfig:
    """The subject matter an infospace explains.

    Attributes:
        name: Human-readable topic name.
        domain: Broader knowledge domain.
        sources: Path (relative to infospace root) to source material.
    """

    name: str
    domain: str = ""
    sources: str = ""

    def to_dict(self) -> Dict[str, Any]:
        d: Dict[str, Any] = {"name": self.name}
        if self.domain:
            d["domain"] = self.domain
        if self.sources:
            d["sources"] = self.sources
        return d

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> TopicConfig:
        return cls(
            name=data["name"],
            domain=data.get("domain", ""),
            sources=data.get("sources", ""),
        )


@dataclass
class DisciplineBinding:
    """An external infospace applied as an analytical lens.

    Attributes:
        name: Human-readable discipline name.
        path: Path to the discipline infospace (relative to root).
    """

    name: str
    path: str = ""

    def to_dict(self) -> Dict[str, Any]:
        d: Dict[str, Any] = {"name": self.name}
        if self.path:
            d["path"] = self.path
        return d

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> DisciplineBinding:
        return cls(name=data["name"], path=data.get("path", ""))


@dataclass
class SchemaRegistry:
    """Schema paths governing entity and document structure.

    All paths are relative to the infospace root directory.
    """

    entity: str = ""
    mapping: str = ""
    analysis: str = ""
    extra: Dict[str, str] = field(default_factory=dict)

    def to_dict(self) -> Dict[str, Any]:
        d: Dict[str, Any] = {}
        if self.entity:
            d["entity"] = self.entity
        if self.mapping:
            d["mapping"] = self.mapping
        if self.analysis:
            d["analysis"] = self.analysis
        d.update(self.extra)
        return d

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> SchemaRegistry:
        known = {"entity", "mapping", "analysis"}
        extra = {k: v for k, v in data.items() if k not in known}
        return cls(
            entity=data.get("entity", ""),
            mapping=data.get("mapping", ""),
            analysis=data.get("analysis", ""),
            extra=extra,
        )


@dataclass
class ViabilityThreshold:
    """Threshold for a single viability metric.

    At least one of *min* or *max* should be set.
    """

    metric: str
    min: Optional[float] = None
    max: Optional[float] = None

    def check(self, value: float) -> bool:
        """Return ``True`` if *value* is within the threshold."""
        if self.min is not None and value < self.min:
            return False
        if self.max is not None and value > self.max:
            return False
        return True

    def to_dict(self) -> Dict[str, Any]:
        d: Dict[str, Any] = {}
        if self.min is not None:
            d["min"] = self.min
        if self.max is not None:
            d["max"] = self.max
        return d


@dataclass
class PipelineStage:
    """A single stage in the processing pipeline.

    Attributes:
        template: Path to the template file (relative to infospace root).
        name: Human-readable stage name used in progress output.
        output_dir: Directory for stage outputs (relative to root).
        output_macro: Macro name for this stage's output, also used as
            the filename suffix (e.g. ``entities`` → ``<id>-entities.md``).
        split_entities: If True, parse ``--- ENTITY: <name> ---`` delimiters
            from LLM output and write individual entity files.
        macros: Static macros loaded from files (macro name → relative path).
        spaces: Legacy space IDs for SQLite-based resolver (unused by
            :class:`SourcePipeline`).
        max_tokens: Maximum tokens to request from the LLM for this stage.
            Overrides the pipeline-level default (4096).
    """

    template: str
    name: str = ""
    output_dir: str = ""
    output_macro: str = ""
    split_entities: bool = False
    macros: Dict[str, str] = field(default_factory=dict)
    spaces: List[str] = field(default_factory=list)
    max_tokens: Optional[int] = None

    def to_dict(self) -> Dict[str, Any]:
        d: Dict[str, Any] = {"template": self.template}
        if self.name:
            d["name"] = self.name
        if self.output_dir:
            d["output_dir"] = self.output_dir
        if self.output_macro:
            d["output_macro"] = self.output_macro
        if self.split_entities:
            d["split_entities"] = self.split_entities
        if self.macros:
            d["macros"] = self.macros
        if self.spaces:
            d["spaces"] = self.spaces
        if self.max_tokens is not None:
            d["max_tokens"] = self.max_tokens
        return d

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> PipelineStage:
        return cls(
            template=data["template"],
            name=data.get("name", ""),
            output_dir=data.get("output_dir", ""),
            output_macro=data.get("output_macro", ""),
            split_entities=data.get("split_entities", False),
            macros=data.get("macros", {}),
            spaces=data.get("spaces", []),
            max_tokens=data.get("max_tokens"),
        )


@dataclass
class PipelineConfig:
    """Processing pipeline configuration."""

    stages: List[PipelineStage] = field(default_factory=list)
    post_batch: List[PipelineStage] = field(default_factory=list)

    def to_dict(self) -> Dict[str, Any]:
        d: Dict[str, Any] = {}
        if self.stages:
            d["stages"] = [s.to_dict() for s in self.stages]
        if self.post_batch:
            d["post_batch"] = [s.to_dict() for s in self.post_batch]
        return d

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> PipelineConfig:
        return cls(
            stages=[PipelineStage.from_dict(s) for s in data.get("stages", [])],
            post_batch=[PipelineStage.from_dict(s) for s in data.get("post_batch", [])],
        )


@dataclass
class InfospaceConfig:
    """Complete infospace configuration, loaded from ``infospace.yaml``.

    This is the declarative description of an infospace: what it
    explains, through which lenses, governed by which schemas, and
    what quality thresholds it must meet.
    """

    topic: TopicConfig
    disciplines: List[DisciplineBinding] = field(default_factory=list)
    schemas: SchemaRegistry = field(default_factory=SchemaRegistry)
    competency_questions: str = ""
    viability: Dict[str, ViabilityThreshold] = field(default_factory=dict)
    pipeline: Optional[PipelineConfig] = None
    entities_dir: str = "output/entities"
    evaluations_dir: str = "output/evaluations"
    metrics_dir: str = "output/metrics"

    def to_dict(self) -> Dict[str, Any]:
        d: Dict[str, Any] = {"topic": self.topic.to_dict()}
        if self.disciplines:
            d["disciplines"] = [db.to_dict() for db in self.disciplines]
        schemas_dict = self.schemas.to_dict()
        if schemas_dict:
            d["schemas"] = schemas_dict
        if self.competency_questions:
            d["competency_questions"] = self.competency_questions
        if self.viability:
            d["viability"] = {
                name: t.to_dict() for name, t in self.viability.items()
            }
        if self.pipeline:
            d["pipeline"] = self.pipeline.to_dict()
        if self.entities_dir != "output/entities":
            d["entities_dir"] = self.entities_dir
        if self.evaluations_dir != "output/evaluations":
            d["evaluations_dir"] = self.evaluations_dir
        if self.metrics_dir != "output/metrics":
            d["metrics_dir"] = self.metrics_dir
        return d

    @classmethod
    def from_dict(cls, data: Dict[str, Any]) -> InfospaceConfig:
        viability_raw = data.get("viability", {})
        viability = {
            name: ViabilityThreshold(metric=name, **bounds)
            for name, bounds in viability_raw.items()
        }
        pipeline_raw = data.get("pipeline")
        pipeline = PipelineConfig.from_dict(pipeline_raw) if pipeline_raw else None

        return cls(
            topic=TopicConfig.from_dict(data["topic"]),
            disciplines=[
                DisciplineBinding.from_dict(d)
                for d in data.get("disciplines", [])
            ],
            schemas=SchemaRegistry.from_dict(data.get("schemas", {})),
            competency_questions=data.get("competency_questions", ""),
            viability=viability,
            pipeline=pipeline,
            entities_dir=data.get("entities_dir", "output/entities"),
            evaluations_dir=data.get("evaluations_dir", "output/evaluations"),
            metrics_dir=data.get("metrics_dir", "output/metrics"),
        )


def load_infospace_config(path: Path) -> InfospaceConfig:
    """Load an :class:`InfospaceConfig` from a YAML file.

    Args:
        path: Path to ``infospace.yaml``.

    Raises:
        FileNotFoundError: If *path* does not exist.
        ValueError: If required fields are missing.
    """
    data = yaml.safe_load(path.read_text(encoding="utf-8"))
    if not isinstance(data, dict):
        raise ValueError(f"Expected a YAML mapping in {path}")
    if "topic" not in data:
        raise ValueError(f"Missing required 'topic' key in {path}")
    return InfospaceConfig.from_dict(data)


def save_infospace_config(config: InfospaceConfig, path: Path) -> None:
    """Write an :class:`InfospaceConfig` to a YAML file."""
    path.parent.mkdir(parents=True, exist_ok=True)
    path.write_text(
        yaml.safe_dump(
            config.to_dict(),
            default_flow_style=False,
            sort_keys=False,
        ),
        encoding="utf-8",
    )


def find_infospace_config(start: Optional[Path] = None) -> Optional[Path]:
    """Walk up from *start* looking for ``infospace.yaml``.

    Returns the path to the config file, or ``None``.
    """
    current = (start or Path.cwd()).resolve()
    for directory in [current, *current.parents]:
        candidate = directory / "infospace.yaml"
        if candidate.is_file():
            return candidate
    return None