"""Catalog and deterministic selector for bundled report-page templates.

HTML skeletons are packaged with the backend so page generation never depends
on the frontend checkout or a browser upload.  Deployments can optionally
override the built-in library with ``DEERFLOW_PAGE_TEMPLATE_DIR``.
"""

from __future__ import annotations

import os
import re
from dataclasses import asdict, dataclass
from hashlib import sha256
from pathlib import Path
from typing import Literal

Theme = Literal["dark", "light"]


@dataclass(frozen=True)
class PageTemplateProfile:
    """A concise, agent-facing description of one HTML report skeleton."""

    id: str
    filename: str
    theme: Theme
    title: str
    style: str
    page_count: int
    features: tuple[str, ...]
    data_entry: str
    best_for: tuple[str, ...]

    def to_dict(self) -> dict[str, object]:
        """Serialize tuples as JSON-friendly lists."""
        value = asdict(self)
        value["features"] = list(self.features)
        value["best_for"] = list(self.best_for)
        return value


# Keep this declarative.  Later templates only require one profile here; their
# original HTML never needs to be copied into the backend or rewritten.
_TEMPLATES: tuple[PageTemplateProfile, ...] = (
    PageTemplateProfile(
        id="dark-charts-portal",
        filename="report-screen-dark-charts-portal-template.html",
        theme="dark",
        title="深蓝图表运营门户",
        style="深蓝科技感、密度较高、带动效的大屏门户",
        page_count=5,
        features=("kpi", "line", "bar", "pie", "radar", "scatter", "gantt", "table", "text-panels", "animation"),
        data_entry="reportData（图表和滚动列表统一入口）",
        best_for=("经营汇报", "数据较多", "多页面", "图表优先", "督办"),
    ),
    PageTemplateProfile(
        id="dark-neon-portal",
        filename="report-screen-dark-neon-portal-template.html",
        theme="dark",
        title="深蓝霓虹专题门户",
        style="深蓝霓虹、沉浸式科技感、内容分区明显",
        page_count=5,
        features=("kpi", "timeline", "table", "text-panels", "animation"),
        data_entry="页面结构直接编辑（先复制再删减）",
        best_for=("专题汇报", "文字较多", "多页面", "研判"),
    ),
    PageTemplateProfile(
        id="dark-neon",
        filename="report-screen-dark-neon-template.html",
        theme="dark",
        title="深蓝霓虹单页大屏",
        style="深蓝发光边框、重点指标突出",
        page_count=1,
        features=("kpi", "line", "bar", "text-panels", "animation"),
        data_entry="页面结构直接编辑（先复制再删减）",
        best_for=("单页汇报", "简洁数据", "值班态势"),
    ),
    PageTemplateProfile(
        id="dark-classic",
        filename="report-screen-dark-template.html",
        theme="dark",
        title="深蓝综合经营大屏",
        style="稳重深蓝、经营驾驶舱、信息密度适中",
        page_count=3,
        features=("kpi", "bar", "table", "timeline", "text-panels"),
        data_entry="页面内置数据变量和结构化区块",
        best_for=("经营汇报", "文字与数据均衡", "三页汇报"),
    ),
    PageTemplateProfile(
        id="light-charts-portal",
        filename="report-screen-light-charts-portal-template.html",
        theme="light",
        title="浅色图表运营门户",
        style="明亮专业、留白充足、带动效的多页面门户",
        page_count=5,
        features=("kpi", "line", "bar", "pie", "radar", "scatter", "gantt", "table", "text-panels", "animation"),
        data_entry="reportData（图表和滚动列表统一入口）",
        best_for=("经营汇报", "数据较多", "多页面", "图表优先", "督办"),
    ),
    PageTemplateProfile(
        id="light-airy-portal",
        filename="report-screen-light-airy-portal-template.html",
        theme="light",
        title="浅色轻盈专题门户",
        style="浅色留白、内容阅读友好、清爽分栏",
        page_count=5,
        features=("kpi", "timeline", "table", "text-panels", "animation"),
        data_entry="页面结构直接编辑（先复制再删减）",
        best_for=("专题汇报", "文字较多", "多页面", "研判"),
    ),
    PageTemplateProfile(
        id="light-airy",
        filename="report-screen-light-airy-template.html",
        theme="light",
        title="浅色轻盈单页报告",
        style="浅色卡片、阅读节奏舒展",
        page_count=1,
        features=("kpi", "bar", "table", "text-panels"),
        data_entry="页面内置数据变量和结构化区块",
        best_for=("单页汇报", "文字为主", "简洁数据"),
    ),
    PageTemplateProfile(
        id="multipage-suite",
        filename="report-screen-multipage-suite-template.html",
        theme="dark",
        title="多页面汇报套件",
        style="深蓝 / 浅色可切换、文字信息组织强、标准化汇报套件",
        page_count=3,
        features=("kpi", "bar", "radar", "gantt", "table", "timeline", "text-panels", "theme-switch"),
        data_entry="reportData（日期、可见页面）+ 页面结构",
        best_for=("多页面", "文字为主", "汇报研判", "行动督办"),
    ),
)


def _template_root_candidates() -> list[Path]:
    explicit = os.getenv("DEERFLOW_PAGE_TEMPLATE_DIR", "").strip()
    candidates: list[Path] = [Path(explicit).expanduser()] if explicit else []
    candidates.append(Path(__file__).resolve().parent / "assets")
    return candidates


def resolve_template_root() -> Path:
    """Locate the template directory or raise a useful deployment error."""
    for candidate in _template_root_candidates():
        if candidate.is_dir():
            return candidate.resolve()
    raise FileNotFoundError(
        "Page template directory is unavailable. Set DEERFLOW_PAGE_TEMPLATE_DIR "
        "to the directory containing the report-screen-*-template.html files."
    )


def _auto_profile(source: Path) -> PageTemplateProfile:
    """Create a conservative profile for a newly dropped-in HTML template.

    Auto-discovered files are intentionally tagged as ``待人工确认`` rather
    than claiming capabilities we cannot prove. The designer can use them for
    broad page requests immediately; a later catalog entry can add richer,
    hand-verified selection metadata without changing the source HTML.
    """
    html = source.read_text(encoding="utf-8", errors="ignore")[:1_000_000]
    lowered = html.lower()
    stem = source.stem
    is_dark = "dark" in stem.lower() or 'data-theme="dark"' in lowered or "#061" in lowered
    features: list[str] = ["text-panels"]
    for feature, hints in {
        "kpi": ("kpi", "metric", "stat-"),
        "line": ("linechart", "line-chart", "line-svg"),
        "bar": ("bar-chart", "bars", "bar >"),
        "pie": ("pie", "donut"),
        "radar": ("radar",),
        "scatter": ("scatter",),
        "gantt": ("gantt",),
        "table": ("<table",),
        "timeline": ("timeline",),
        "animation": ("@keyframes", "requestanimationframe", "transition:"),
    }.items():
        if any(hint in lowered for hint in hints):
            features.append(feature)
    page_count = max(
        1,
        len(re.findall(r"\bdata-page\s*=", lowered)),
        len(re.findall(r"\breport-page\b", lowered)),
    )
    identifier = "auto-" + sha256(source.name.encode("utf-8")).hexdigest()[:10]
    return PageTemplateProfile(
        id=identifier,
        filename=source.name,
        theme="dark" if is_dark else "light",
        title=f"自动发现：{stem}",
        style="自动发现的 HTML 页面骨架（能力待人工确认）",
        page_count=page_count,
        features=tuple(dict.fromkeys(features)),
        data_entry="reportData" if "const reportdata" in lowered else "页面结构直接编辑（先复制再删减）",
        best_for=("自动发现", "待人工确认"),
    )


def list_template_profiles() -> tuple[PageTemplateProfile, ...]:
    """Return registered templates plus safely auto-discovered future files."""
    profiles = list(_TEMPLATES)
    known_filenames = {profile.filename for profile in profiles}
    try:
        root = resolve_template_root()
        for source in sorted(root.glob("report-screen-*-template.html"), key=lambda item: item.name.lower()):
            if source.name not in known_filenames:
                profiles.append(_auto_profile(source))
    except (FileNotFoundError, OSError):
        # Catalog information remains useful in deployments where the frontend
        # package is not mounted yet; prepare() will surface the real error.
        pass
    return tuple(profiles)


def get_template_profile(template_id: str) -> PageTemplateProfile:
    normalized = (template_id or "").strip().lower()
    for profile in list_template_profiles():
        if profile.id == normalized:
            return profile
    available = ", ".join(profile.id for profile in list_template_profiles())
    raise ValueError(f"Unknown page template '{template_id}'. Available: {available}")


def resolve_template_file(template_id: str) -> Path:
    """Return a verified source-template path for a catalog id."""
    profile = get_template_profile(template_id)
    source = (resolve_template_root() / profile.filename).resolve()
    root = resolve_template_root()
    try:
        source.relative_to(root)
    except ValueError as exc:  # defensive: profile filenames are repository data
        raise ValueError("Template path escapes the template root") from exc
    if not source.is_file():
        raise FileNotFoundError(
            f"Template '{template_id}' is listed in the catalog but is missing: {source}"
        )
    return source


def _normalize_theme(theme: str | None) -> Theme | None:
    value = (theme or "").strip().lower()
    if value in {"dark", "deep-blue", "dark-blue"}:
        return "dark"
    if value in {"light", "white", "bright"}:
        return "light"
    return None


def _score_template(
    profile: PageTemplateProfile,
    *,
    content_density: str,
    required_features: set[str],
    preferred_page_count: int | None,
) -> int:
    score = 0
    features = set(profile.features)
    # A required feature weighs substantially more than aesthetics.
    score += 12 * len(features & required_features)
    score -= 30 * len(required_features - features)
    density = (content_density or "balanced").strip().lower()
    if density in {"text-heavy", "rich-text", "文字较多"} and "text-panels" in features:
        score += 8
    if density in {"data-heavy", "chart-heavy", "图表较多"} and {"line", "bar", "pie"}.issubset(features):
        score += 8
    if preferred_page_count:
        score -= min(abs(profile.page_count - preferred_page_count), 3) * 3
    return score


def choose_template(
    *,
    theme: str | None,
    content_density: str = "balanced",
    required_features: list[str] | None = None,
    preferred_page_count: int | None = None,
    selection_key: str = "",
    exclude_template_ids: list[str] | None = None,
) -> PageTemplateProfile:
    """Choose a suitable template, varying ties deterministically by request.

    The caller can pass recent choices through ``exclude_template_ids``.  We
    only fall back to an excluded item when it is the sole match for the chosen
    theme, which prevents an agent from losing the requested colour mode.
    """
    target_theme = _normalize_theme(theme)
    all_profiles = list_template_profiles()
    candidates = [profile for profile in all_profiles if target_theme is None or profile.theme == target_theme]
    if not candidates:
        candidates = list(all_profiles)
    excluded = {value.strip().lower() for value in (exclude_template_ids or []) if value.strip()}
    non_excluded = [profile for profile in candidates if profile.id not in excluded]
    if non_excluded:
        candidates = non_excluded
    feature_set = {value.strip().lower() for value in (required_features or []) if value.strip()}
    scored = sorted(
        ((
            _score_template(
                profile,
                content_density=content_density,
                required_features=feature_set,
                preferred_page_count=preferred_page_count,
            ),
            profile,
        ) for profile in candidates),
        key=lambda item: (-item[0], item[1].id),
    )
    best_score = scored[0][0]
    ties = [profile for score, profile in scored if score == best_score]
    if len(ties) == 1:
        return ties[0]
    digest = sha256((selection_key or "page-report").encode("utf-8")).digest()
    return ties[int.from_bytes(digest[:4], "big") % len(ties)]


__all__ = [
    "PageTemplateProfile",
    "choose_template",
    "get_template_profile",
    "list_template_profiles",
    "resolve_template_file",
    "resolve_template_root",
]