from __future__ import annotations

import json
from unittest.mock import MagicMock

import pymupdf

from app.services import pdf_image_extractor as mod
from app.services.layout_detector import LayoutBox


def _caption_block(bbox, text):
    """构造一个 page.get_text("dict") 风格的文本块。"""
    return {
        "type": 0,
        "bbox": list(bbox),
        "lines": [{"spans": [{"text": text}]}],
    }


def test_process_page_pairs_caption_from_text(tmp_path):
    """caption 来自 PDF 文本流（figure 标题在内容下方），用其 ID 直接命名。"""
    images_dest = tmp_path / "images"
    images_dest.mkdir()
    manifest: dict[str, dict] = {}

    pix = MagicMock()
    pix.tobytes.return_value = b"jpeg"

    page = MagicMock()
    page.rect.width = 600
    page.rect.height = 800
    page.get_pixmap.return_value = pix
    page.get_text.return_value = {
        "blocks": [
            _caption_block((95, 310, 320, 325), "Figure 1: Overall architecture.")
        ]
    }

    doc = MagicMock()
    doc.__getitem__.return_value = page

    boxes = [LayoutBox(100, 100, 300, 300, "picture")]

    extracted = mod._process_page(
        doc,
        0,
        boxes,
        images_dest=images_dest,
        manifest=manifest,
        seen_labels=set(),
        arxiv_id="2401.00001",
    )

    assert extracted == 1
    # caption 自带 ID → 直接命名 figure_1.jpg
    info = manifest["figure_1.jpg"]
    assert info["label"] == "Figure 1"
    assert info["caption_text"] == "Figure 1: Overall architecture."
    assert info["caption_source"] == "text"


def test_process_page_includes_caption_in_render(tmp_path):
    """渲染时把 caption 文本块区域合并进同一张截图。"""
    images_dest = tmp_path / "images"
    images_dest.mkdir()
    manifest: dict[str, dict] = {}

    pix = MagicMock()
    pix.tobytes.return_value = b"jpeg"

    page = MagicMock()
    page.rect.width = 600
    page.rect.height = 800
    page.get_pixmap.return_value = pix
    page.get_text.return_value = {
        "blocks": [_caption_block((95, 310, 320, 325), "Figure 1: Caption text.")]
    }

    doc = MagicMock()
    doc.__getitem__.return_value = page

    boxes = [LayoutBox(100, 100, 300, 300, "picture")]

    mod._process_page(
        doc,
        0,
        boxes,
        images_dest=images_dest,
        manifest=manifest,
        seen_labels=set(),
        arxiv_id="2401.00001",
    )

    # 内容 [100,100,300,300] ∪ caption [95,310,320,325]，各方向加 _REGION_PADDING=5
    # → Rect(90, 95, 325, 330)
    clip = page.get_pixmap.call_args.kwargs["clip"]
    assert clip == pymupdf.Rect(90, 95, 325, 330)


def test_process_page_table_caption_above(tmp_path):
    """table 标题惯例在内容上方，配对后命名 table_N.jpg。"""
    images_dest = tmp_path / "images"
    images_dest.mkdir()
    manifest: dict[str, dict] = {}

    pix = MagicMock()
    pix.tobytes.return_value = b"jpeg"

    page = MagicMock()
    page.rect.width = 600
    page.rect.height = 800
    page.get_pixmap.return_value = pix
    # caption 在内容上方 [80, 90, 320, 105]，内容表格 [80, 120, 320, 280]
    page.get_text.return_value = {
        "blocks": [_caption_block((80, 90, 320, 105), "Table 2 | Results summary.")]
    }

    doc = MagicMock()
    doc.__getitem__.return_value = page

    boxes = [LayoutBox(80, 120, 320, 280, "table")]

    extracted = mod._process_page(
        doc,
        0,
        boxes,
        images_dest=images_dest,
        manifest=manifest,
        seen_labels=set(),
        arxiv_id="2401.00001",
    )

    assert extracted == 1
    info = manifest["table_2.jpg"]
    assert info["label"] == "Table 2"
    assert info["caption_source"] == "text"


def test_process_page_filters_uncaptioned(tmp_path):
    """没有 Figure/Table caption 配对的 box（Algorithm、无编号表等）被过滤，不输出。"""
    images_dest = tmp_path / "images"
    images_dest.mkdir()
    manifest: dict[str, dict] = {}

    pix = MagicMock()
    pix.tobytes.return_value = b"jpeg"

    page = MagicMock()
    page.rect.width = 600
    page.rect.height = 800
    page.get_pixmap.return_value = pix
    page.get_text.return_value = {"blocks": []}  # 无任何 caption 文本块

    doc = MagicMock()
    doc.__getitem__.return_value = page

    boxes = [LayoutBox(100, 100, 300, 300, "picture")]

    extracted = mod._process_page(
        doc,
        0,
        boxes,
        images_dest=images_dest,
        manifest=manifest,
        seen_labels=set(),
        arxiv_id="2401.00001",
    )

    assert extracted == 0
    assert manifest == {}


def test_process_page_merges_subfigure_clusters(tmp_path):
    """复合图被切成多个稀疏子图框时，配到同一主 caption 后合并成一张截图。"""
    images_dest = tmp_path / "images"
    images_dest.mkdir()
    manifest: dict[str, dict] = {}

    pix = MagicMock()
    pix.tobytes.return_value = b"jpeg"

    page = MagicMock()
    page.rect.width = 600
    page.rect.height = 800
    page.get_pixmap.return_value = pix
    # 主 caption 覆盖整张复合图宽度，在内容下方
    page.get_text.return_value = {
        "blocks": [_caption_block((95, 410, 455, 425), "Figure 3: Composite figure.")]
    }

    doc = MagicMock()
    doc.__getitem__.return_value = page

    # 两个子图框左右排列，间距 50pt（> _CLUSTER_GAP=15，不被 _cluster_boxes 合并）
    boxes = [
        LayoutBox(100, 100, 250, 300, "picture"),
        LayoutBox(300, 100, 450, 300, "picture"),
    ]

    extracted = mod._process_page(
        doc,
        0,
        boxes,
        images_dest=images_dest,
        manifest=manifest,
        seen_labels=set(),
        arxiv_id="2401.00003",
    )

    assert extracted == 1  # 两子图合并成一张
    info = manifest["figure_3.jpg"]
    assert info["label"] == "Figure 3"
    assert info["subfigure_count"] == 2
    # 合并 bbox = union 两子图 = [100,100,450,300]
    assert info["box"] == [100.0, 100.0, 450.0, 300.0]


def test_process_page_two_tables_captions_below_not_merged(tmp_path):
    """同页相邻两张表、标题都在表下方时，各自配对自己的内容框，不互相吞并。

    回归 2606.19926：Table 3/4 同页、两标题均在表下方。旧逻辑（table 标题
    必在上的错向惩罚）会让 Table 3 吞掉 Table 4 的内容框、Table 4 缺图。
    """
    images_dest = tmp_path / "images"
    images_dest.mkdir()
    manifest: dict[str, dict] = {}

    pix = MagicMock()
    pix.tobytes.return_value = b"jpeg"

    page = MagicMock()
    page.rect.width = 600
    page.rect.height = 800
    page.get_pixmap.return_value = pix
    # 两个 table 标题都在各自内容下方（本文实际排版）
    page.get_text.return_value = {
        "blocks": [
            _caption_block((80, 324, 460, 346), "Table 3 Pass@1 success rate."),
            _caption_block((80, 503, 460, 547), "Table 4 Core gold-context metrics."),
        ]
    }

    doc = MagicMock()
    doc.__getitem__.return_value = page

    boxes = [
        LayoutBox(80, 77, 460, 321, "table"),  # Table 3 内容（上）
        LayoutBox(80, 420, 460, 494, "table"),  # Table 4 内容（下）
    ]

    extracted = mod._process_page(
        doc,
        0,
        boxes,
        images_dest=images_dest,
        manifest=manifest,
        seen_labels=set(),
        arxiv_id="2606.19926",
    )

    assert extracted == 2
    assert "table_3.jpg" in manifest
    assert "table_4.jpg" in manifest
    # 各自只含自己的内容框，未被合并成一张大图
    assert manifest["table_3.jpg"]["box"] == [80.0, 77.0, 460.0, 321.0]
    assert manifest["table_4.jpg"]["box"] == [80.0, 420.0, 460.0, 494.0]
    assert "subfigure_count" not in manifest["table_3.jpg"]
    assert "subfigure_count" not in manifest["table_4.jpg"]


def test_caption_regex_rejects_multi_reference_body_text():
    """多图引用型正文（"Figure 14 and 15 show..."）不应被当作独立 caption。

    回归 2606.24597：第 35 页正文 "Figure 14 and 15 show..." 被误判为 caption，
    与真标题 "Figure 14:" 竞争 seen_labels 去重，导致 Figure 14 截成另一张图。
    """
    re_ = mod._CAPTION_HEAD_RE
    # 真标题：编号后接标题文字 / 冒号 / 子图编号，均应命中
    assert re_.match("Figure 14: Interaction examples.")
    assert re_.match("Figure 1 Context efficiency.")
    assert re_.match("Table 1 Zero-shot results.")
    assert re_.match("Figure 3.5 Sub-figure detail.")
    # 多图引用正文：编号后紧跟 "and/to/, + 另一编号" → 拒绝
    assert not re_.match("Figure 14 and 15 show representative examples.")
    assert not re_.match("Figure 1 to 3 illustrate the pipeline.")
    assert not re_.match("Table 2, 3 compare methods.")


def test_link_figures_fallback_excludes_assigned_images(tmp_path, monkeypatch):
    """序号兜底不复用已被精确匹配（策略 1）占用的图片。

    回归 2606.19926：Table 4 在 manifest 缺图 → 兜底误取 table_1.jpg（已属 Table 1）。
    """
    monkeypatch.setattr(mod, "PAPERS_DIR", tmp_path)
    images_dir = tmp_path / "x" / "images"
    images_dir.mkdir(parents=True)
    # manifest 只命中 Table 1 → table_1.jpg；Table 4 无精确匹配，走兜底
    (images_dir / "manifest.json").write_text(
        json.dumps({"table_1.jpg": {"label": "Table 1"}})
    )

    figures = [{"id": "Table 1"}, {"id": "Table 4"}]
    images = [
        {"name": "table_1.jpg", "url": "/papers/x/images/table_1.jpg"},
        {"name": "table_2.jpg", "url": "/papers/x/images/table_2.jpg"},
    ]

    out = mod.link_figures_with_images(figures, images, "x")
    by_id = {f["id"]: f for f in out}

    assert by_id["Table 1"]["image_url"] == "/papers/x/images/table_1.jpg"
    # 兜底只能拿到未被占用的 table_2.jpg，不能再复用 table_1.jpg
    assert by_id["Table 4"]["image_url"] == "/papers/x/images/table_2.jpg"


def test_process_page_absorbs_far_subfigure_panel(tmp_path):
    """多面板图主 caption 只在最下方时，距 caption 过远的上方面板被吸收进来。

    回归 2606.24597 Figure 4：(a) 子图距主标题 270pt（> _CAPTION_MATCH_DISTANCE），
    原本被丢弃；(b) 子图距 46pt 正常配对。吸收后两面板合并成一张含 (a)(b)。
    """
    images_dest = tmp_path / "images"
    images_dest.mkdir()
    manifest: dict[str, dict] = {}

    pix = MagicMock()
    pix.tobytes.return_value = b"jpeg"
    page = MagicMock()
    page.rect.width = 600
    page.rect.height = 800
    page.get_pixmap.return_value = pix
    # 主 caption 在最下方 y=479，距上方 (a) 面板 270pt、距 (b) 面板 46pt
    page.get_text.return_value = {
        "blocks": [
            _caption_block((80, 479, 520, 500), "Figure 4: Representative examples.")
        ]
    }
    doc = MagicMock()
    doc.__getitem__.return_value = page
    boxes = [
        LayoutBox(80, 73, 520, 209, "picture"),  # (a) 面板，距 caption 270pt
        LayoutBox(80, 245, 520, 433, "picture"),  # (b) 面板，距 caption 46pt
    ]

    extracted = mod._process_page(
        doc,
        0,
        boxes,
        images_dest=images_dest,
        manifest=manifest,
        seen_labels=set(),
        arxiv_id="2606.24597",
    )

    assert extracted == 1
    info = manifest["figure_4.jpg"]
    # 合并后含两面板：y 从 73 到 433
    assert info["box"] == [80.0, 73.0, 520.0, 433.0]
    assert info["subfigure_count"] == 2


def test_process_page_absorbs_chained_panels_multipass(tmp_path):
    """链式排列的多面板（上图→中图→下图→caption）需多趟吸收才能全部并入。

    回归 2606.24597 Figure 15：3 个面板纵排、主 caption 只在最下方，中图被并入后
    上图才能链上。单趟扫描会漏掉最上图。
    """
    images_dest = tmp_path / "images"
    images_dest.mkdir()
    manifest: dict[str, dict] = {}

    pix = MagicMock()
    pix.tobytes.return_value = b"jpeg"
    page = MagicMock()
    page.rect.width = 600
    page.rect.height = 800
    page.get_pixmap.return_value = pix
    # 主 caption 在最下方 y=710，仅下图（y505-669）在其 120pt 内
    page.get_text.return_value = {
        "blocks": [
            _caption_block((80, 710, 520, 730), "Figure 15: Text-based domains.")
        ]
    }
    doc = MagicMock()
    doc.__getitem__.return_value = page
    boxes = [
        LayoutBox(80, 73, 520, 217, "picture"),  # 上图，距 caption 493pt
        LayoutBox(80, 256, 520, 467, "picture"),  # 中图，距 caption 243pt
        LayoutBox(80, 505, 520, 669, "picture"),  # 下图，距 caption 41pt（配得上）
    ]

    extracted = mod._process_page(
        doc,
        0,
        boxes,
        images_dest=images_dest,
        manifest=manifest,
        seen_labels=set(),
        arxiv_id="2606.24597",
    )

    assert extracted == 1
    info = manifest["figure_15.jpg"]
    # 三面板全并入：y 从 73 到 669
    assert info["box"] == [80.0, 73.0, 520.0, 669.0]
    assert info["subfigure_count"] == 3


def test_absorb_stragglers_respects_caption_boundary(tmp_path):
    """两图之间夹着（异类）标题时，漏配的上图不并入下图（吸收护栏 2）。

    上图距下图标题 160pt（>120）漏配；下图正常配对。两图间夹一个 Table 标题
    （异类，上图不会配它）→ 护栏判定有 caption 边界，不吸收上图。
    """
    images_dest = tmp_path / "images"
    images_dest.mkdir()
    manifest: dict[str, dict] = {}

    pix = MagicMock()
    pix.tobytes.return_value = b"jpeg"
    page = MagicMock()
    page.rect.width = 600
    page.rect.height = 800
    page.get_pixmap.return_value = pix
    page.get_text.return_value = {
        "blocks": [
            _caption_block(
                (80, 160, 460, 175), "Table 9 Some table."
            ),  # 夹中间的表标题
            _caption_block((80, 310, 520, 330), "Figure 5 Some figure."),  # 下图标题
        ]
    }
    doc = MagicMock()
    doc.__getitem__.return_value = page
    boxes = [
        LayoutBox(80, 73, 520, 150, "picture"),  # 上图，距 Figure 5 标题 160pt → 漏配
        LayoutBox(80, 185, 520, 300, "picture"),  # 下图，距 Figure 5 标题 10pt → 配上
    ]

    extracted = mod._process_page(
        doc,
        0,
        boxes,
        images_dest=images_dest,
        manifest=manifest,
        seen_labels=set(),
        arxiv_id="2606.24597",
    )

    # 上图未被并入下图 → 仅下图输出，box 不含上图、无 subfigure_count
    assert extracted == 1
    assert manifest["figure_5.jpg"]["box"] == [80.0, 185.0, 520.0, 300.0]
    assert "subfigure_count" not in manifest["figure_5.jpg"]