"""Data extraction tools: save_texture, get_buffer_data, pick_pixel, get_texture_stats, export_draw_textures, save_render_target, export_mesh."""


import os
from typing import Optional

from ..session import get_session
from ..util import (
    rd,
    make_error,
    enum_str,
    FILE_TYPE_MAP,
    SHADER_STAGE_MAP,
    MESH_DATA_STAGE_MAP,
    TOPOLOGY_MAP,
)


MAX_BUFFER_READ = 65536


def save_texture(
    resource_id: str,
    output_path: str,
    file_type: str = "png",
    mip: int = 0,
    event_id: Optional[int] = None,
) -> dict:
    """Save a texture resource to an image file.

    Args:
        resource_id: The texture resource ID string.
        output_path: Absolute path for the output file.
        file_type: Output format: png, jpg, bmp, tga, hdr, exr, dds (default: png).
        mip: Mip level to save (default 0). Use -1 for all mips (DDS only).
        event_id: Optional event ID to navigate to first.
    """
    session = get_session()
    err = session.require_open()
    if err:
        return err
    err = session.ensure_event(event_id)
    if err:
        return err

    tex_id = session.resolve_resource_id(resource_id)
    if tex_id is None:
        return make_error(
            f"Texture resource '{resource_id}' not found", "INVALID_RESOURCE_ID"
        )

    ft = FILE_TYPE_MAP.get(file_type.lower())
    if ft is None:
        return make_error(
            f"Unknown file type: {file_type}. Valid: {list(FILE_TYPE_MAP.keys())}",
            "API_ERROR",
        )

    output_path = os.path.normpath(output_path)
    os.makedirs(os.path.dirname(output_path) or ".", exist_ok=True)

    texsave = rd.TextureSave()
    texsave.resourceId = tex_id
    texsave.destType = ft
    texsave.mip = mip
    texsave.slice.sliceIndex = 0
    texsave.alpha = rd.AlphaMapping.Preserve

    session.controller.SaveTexture(texsave, output_path)

    return {
        "status": "saved",
        "output_path": output_path,
        "resource_id": resource_id,
        "file_type": file_type,
        "mip": mip,
    }


def get_buffer_data(
    resource_id: str,
    offset: int = 0,
    length: int = 256,
    format: str = "hex",
) -> dict:
    """Read raw data from a buffer resource.

    Args:
        resource_id: The buffer resource ID string.
        offset: Byte offset to start reading from (default 0).
        length: Number of bytes to read (default 256, max 65536).
        format: Output format: "hex" for hex dump, "floats" to interpret as float32 array.
    """
    session = get_session()
    err = session.require_open()
    if err:
        return err

    buf_id = session.resolve_resource_id(resource_id)
    if buf_id is None:
        return make_error(
            f"Buffer resource '{resource_id}' not found", "INVALID_RESOURCE_ID"
        )

    length = min(length, MAX_BUFFER_READ)
    data = session.controller.GetBufferData(buf_id, offset, length)

    result: dict = {
        "resource_id": resource_id,
        "offset": offset,
        "bytes_read": len(data),
    }

    if format == "floats":
        import struct

        num_floats = len(data) // 4
        floats = list(struct.unpack_from(f"{num_floats}f", data))
        result["data"] = [round(f, 6) for f in floats]
        result["format"] = "float32"
    else:
        lines = []
        for i in range(0, len(data), 16):
            chunk = data[i : i + 16]
            hex_part = " ".join(f"{b:02x}" for b in chunk)
            lines.append(f"{offset + i:08x}: {hex_part}")
        result["data"] = "\n".join(lines)
        result["format"] = "hex"

    return result


def pick_pixel(
    resource_id: str,
    x: int,
    y: int,
    event_id: Optional[int] = None,
) -> dict:
    """Get the RGBA value of a specific pixel in a texture.

    Args:
        resource_id: The texture resource ID string.
        x: X coordinate of the pixel.
        y: Y coordinate of the pixel.
        event_id: Optional event ID to navigate to first.
    """
    session = get_session()
    err = session.require_open()
    if err:
        return err
    err = session.ensure_event(event_id)
    if err:
        return err

    tex_id = session.resolve_resource_id(resource_id)
    if tex_id is None:
        return make_error(
            f"Texture resource '{resource_id}' not found", "INVALID_RESOURCE_ID"
        )

    val = session.controller.PickPixel(
        tex_id, x, y, rd.Subresource(0, 0, 0), rd.CompType.Typeless
    )

    return {
        "resource_id": resource_id,
        "x": x,
        "y": y,
        "rgba": {
            "r": val.floatValue[0],
            "g": val.floatValue[1],
            "b": val.floatValue[2],
            "a": val.floatValue[3],
        },
        "rgba_uint": {
            "r": val.uintValue[0],
            "g": val.uintValue[1],
            "b": val.uintValue[2],
            "a": val.uintValue[3],
        },
    }


def get_texture_stats(
    resource_id: str,
    event_id: Optional[int] = None,
    all_slices: bool = False,
) -> dict:
    """Get min/max/average statistics for a texture at the current event.

    Args:
        resource_id: The texture resource ID string.
        event_id: Optional event ID to navigate to first.
        all_slices: If True, return per-slice/per-face statistics. Useful for
                    cubemaps (returns stats for each of the 6 faces) and texture arrays.
                    Default False returns only slice 0.
    """
    session = get_session()
    err = session.require_open()
    if err:
        return err
    err = session.ensure_event(event_id)
    if err:
        return err

    tex_id = session.resolve_resource_id(resource_id)
    if tex_id is None:
        return make_error(
            f"Texture resource '{resource_id}' not found", "INVALID_RESOURCE_ID"
        )

    tex_desc = session.get_texture_desc(resource_id)

    def _minmax_to_dict(mm):
        mn, mx = mm[0], mm[1]
        r_min, g_min, b_min, a_min = (
            mn.floatValue[0],
            mn.floatValue[1],
            mn.floatValue[2],
            mn.floatValue[3],
        )
        r_max, g_max, b_max, a_max = (
            mx.floatValue[0],
            mx.floatValue[1],
            mx.floatValue[2],
            mx.floatValue[3],
        )
        has_neg = any(v < 0 for v in [r_min, g_min, b_min])
        import math

        has_inf = any(math.isinf(v) for v in [r_max, g_max, b_max])
        has_nan = any(math.isnan(v) for v in [r_min, g_min, b_min, r_max, g_max, b_max])
        d: dict = {
            "min": {"r": r_min, "g": g_min, "b": b_min, "a": a_min},
            "max": {"r": r_max, "g": g_max, "b": b_max, "a": a_max},
            "has_negative": has_neg,
            "has_inf": has_inf,
            "has_nan": has_nan,
        }
        warnings = []
        if has_nan:
            warnings.append("⚠️ 检测到 NaN 值")
        if has_inf:
            warnings.append("⚠️ 检测到 Inf 值")
        if has_neg:
            warnings.append("⚠️ 检测到负值")
        if warnings:
            d["warnings"] = warnings
        return d

    result: dict = {"resource_id": resource_id}
    if tex_desc is not None:
        result["name"] = getattr(tex_desc, "name", "")
        result["size"] = f"{tex_desc.width}x{tex_desc.height}"
        result["format"] = str(tex_desc.format.Name())
        result["mips"] = tex_desc.mips
        result["array_size"] = tex_desc.arraysize

    _FACE_NAMES = ["+X", "-X", "+Y", "-Y", "+Z", "-Z"]

    if all_slices and tex_desc is not None:
        num_slices = max(tex_desc.arraysize, 1)
        is_cubemap = num_slices == 6 or (
            hasattr(tex_desc, "dimension") and "Cube" in str(tex_desc.dimension)
        )
        per_slice = []
        for s in range(num_slices):
            try:
                mm = session.controller.GetMinMax(
                    tex_id, rd.Subresource(0, s, 0), rd.CompType.Typeless
                )
                entry = _minmax_to_dict(mm)
                if is_cubemap and s < 6:
                    entry["face"] = _FACE_NAMES[s]
                else:
                    entry["slice"] = s
                per_slice.append(entry)
            except Exception as e:
                per_slice.append({"slice": s, "error": str(e)})
        result["per_slice_stats"] = per_slice
    else:
        mm = session.controller.GetMinMax(
            tex_id, rd.Subresource(0, 0, 0), rd.CompType.Typeless
        )
        result.update(_minmax_to_dict(mm))

    return result


def read_texture_pixels(
    resource_id: str,
    x: int,
    y: int,
    width: int,
    height: int,
    mip_level: int = 0,
    array_slice: int = 0,
    event_id: Optional[int] = None,
) -> dict:
    """Read actual pixel values from a rectangular region of a texture.

    Returns float RGBA values for each pixel. Region is capped at 64x64.
    Useful for precisely checking IBL cubemap faces, LUT textures, history buffers, etc.

    Args:
        resource_id: The texture resource ID string.
        x: Top-left X coordinate of the region.
        y: Top-left Y coordinate of the region.
        width: Region width (max 64).
        height: Region height (max 64).
        mip_level: Mip level to read (default 0).
        array_slice: Array slice or cubemap face index (default 0).
                     Cubemap face order: 0=+X 1=-X 2=+Y 3=-Y 4=+Z 5=-Z.
        event_id: Optional event ID to navigate to first.
    """
    import struct as _struct
    import math as _math

    session = get_session()
    err = session.require_open()
    if err:
        return err
    err = session.ensure_event(event_id)
    if err:
        return err

    tex_id = session.resolve_resource_id(resource_id)
    if tex_id is None:
        return make_error(
            f"Texture resource '{resource_id}' not found", "INVALID_RESOURCE_ID"
        )

    width = min(width, 64)
    height = min(height, 64)

    pixels: list = []
    anomalies: list = []

    for py in range(y, y + height):
        row: list = []
        for px in range(x, x + width):
            try:
                val = session.controller.PickPixel(
                    tex_id,
                    px,
                    py,
                    rd.Subresource(mip_level, array_slice, 0),
                    rd.CompType.Typeless,
                )
                r, g, b, a = (
                    val.floatValue[0],
                    val.floatValue[1],
                    val.floatValue[2],
                    val.floatValue[3],
                )
                pixel = [round(r, 6), round(g, 6), round(b, 6), round(a, 6)]
                row.append(pixel)

                for ch_idx, ch_val in enumerate(pixel[:3]):
                    ch_name = "rgba"[ch_idx]
                    if _math.isnan(ch_val):
                        anomalies.append(
                            {"x": px, "y": py, "channel": ch_name, "type": "NaN"}
                        )
                    elif _math.isinf(ch_val):
                        anomalies.append(
                            {
                                "x": px,
                                "y": py,
                                "channel": ch_name,
                                "type": "Inf",
                                "value": str(ch_val),
                            }
                        )
                    elif ch_val < 0:
                        anomalies.append(
                            {
                                "x": px,
                                "y": py,
                                "channel": ch_name,
                                "type": "negative",
                                "value": round(ch_val, 6),
                            }
                        )
            except Exception as e:
                row.append({"error": str(e)})
        pixels.append(row)

    result: dict = {
        "resource_id": resource_id,
        "region": {"x": x, "y": y, "width": width, "height": height},
        "mip_level": mip_level,
        "array_slice": array_slice,
        "pixels": pixels,
    }
    if anomalies:
        result["anomalies"] = anomalies
        result["anomaly_count"] = len(anomalies)
    return result


def export_draw_textures(
    event_id: int,
    output_dir: str,
    skip_small: bool = True,
) -> dict:
    """Batch export all textures bound to a draw call's pixel shader.

    Args:
        event_id: The event ID of the draw call.
        output_dir: Directory to save exported textures.
        skip_small: Skip textures 4x4 or smaller (placeholder textures). Default True.
    """
    session = get_session()
    err = session.require_open()
    if err:
        return err
    err = session.set_event(event_id)
    if err:
        return err

    state = session.controller.GetPipelineState()
    ps_refl = state.GetShaderReflection(rd.ShaderStage.Pixel)
    if ps_refl is None:
        return make_error("No pixel shader bound at this event", "API_ERROR")

    output_dir = os.path.normpath(output_dir)
    os.makedirs(output_dir, exist_ok=True)

    exported = []
    skipped = []
    try:
        all_ro = state.GetReadOnlyResources(rd.ShaderStage.Pixel)
        ro_by_index: dict = {}
        for b in all_ro:
            ro_by_index.setdefault(b.access.index, []).append(b)
    except Exception:
        ro_by_index = {}

    for i, ro_refl in enumerate(ps_refl.readOnlyResources):
        for b in ro_by_index.get(i, []):
            rid_str = str(b.descriptor.resource)
            tex_desc = session.get_texture_desc(rid_str)
            if tex_desc is None:
                continue

            if skip_small and tex_desc.width <= 4 and tex_desc.height <= 4:
                skipped.append(
                    {
                        "name": ro_refl.name,
                        "resource_id": rid_str,
                        "size": f"{tex_desc.width}x{tex_desc.height}",
                    }
                )
                continue

            filename = f"{ro_refl.name}_{tex_desc.width}x{tex_desc.height}.png"
            filename = filename.replace("/", "_").replace("\\", "_")
            out_path = os.path.join(output_dir, filename)

            texsave = rd.TextureSave()
            texsave.resourceId = tex_desc.resourceId
            texsave.destType = rd.FileType.PNG
            texsave.mip = 0
            texsave.slice.sliceIndex = 0
            texsave.alpha = rd.AlphaMapping.Preserve
            session.controller.SaveTexture(texsave, out_path)

            exported.append(
                {
                    "name": ro_refl.name,
                    "resource_id": rid_str,
                    "size": f"{tex_desc.width}x{tex_desc.height}",
                    "output_path": out_path,
                }
            )

    return {
        "event_id": event_id,
        "exported": exported,
        "exported_count": len(exported),
        "skipped": skipped,
        "skipped_count": len(skipped),
    }


def save_render_target(
    event_id: int,
    output_path: str,
    save_depth: bool = False,
) -> dict:
    """Save the current render target(s) at a specific event.

    Args:
        event_id: The event ID to capture the render target from.
        output_path: Output file path or directory. If directory, auto-names the file.
        save_depth: Also save the depth target (default False).
    """
    session = get_session()
    err = session.require_open()
    if err:
        return err
    err = session.set_event(event_id)
    if err:
        return err

    state = session.controller.GetPipelineState()
    output_path = os.path.normpath(output_path)
    saved = []

    outputs = state.GetOutputTargets()
    color_target = None
    for o in outputs:
        if int(o.resource) != 0:
            color_target = o
            break

    if color_target is None:
        return make_error("No color render target bound at this event", "API_ERROR")

    rid_str = str(color_target.resource)
    tex_desc = session.get_texture_desc(rid_str)

    if os.path.isdir(output_path):
        fname = f"rt_color_eid{event_id}.png"
        color_path = os.path.join(output_path, fname)
    else:
        color_path = output_path
        os.makedirs(os.path.dirname(color_path) or ".", exist_ok=True)

    texsave = rd.TextureSave()
    texsave.resourceId = color_target.resource
    texsave.destType = rd.FileType.PNG
    texsave.mip = 0
    texsave.slice.sliceIndex = 0
    texsave.alpha = rd.AlphaMapping.Preserve
    session.controller.SaveTexture(texsave, color_path)

    color_info: dict = {
        "type": "color",
        "resource_id": rid_str,
        "output_path": color_path,
    }
    if tex_desc is not None:
        color_info["size"] = f"{tex_desc.width}x{tex_desc.height}"
        color_info["format"] = str(tex_desc.format.Name())
    saved.append(color_info)

    if save_depth:
        try:
            dt = state.GetDepthTarget()
            if int(dt.resource) != 0:
                dt_rid = str(dt.resource)
                if os.path.isdir(output_path):
                    depth_path = os.path.join(
                        output_path, f"rt_depth_eid{event_id}.png"
                    )
                else:
                    base, ext = os.path.splitext(color_path)
                    depth_path = f"{base}_depth{ext}"

                texsave = rd.TextureSave()
                texsave.resourceId = dt.resource
                texsave.destType = rd.FileType.PNG
                texsave.mip = 0
                texsave.slice.sliceIndex = 0
                texsave.alpha = rd.AlphaMapping.Preserve
                session.controller.SaveTexture(texsave, depth_path)

                depth_info: dict = {
                    "type": "depth",
                    "resource_id": dt_rid,
                    "output_path": depth_path,
                }
                dt_desc = session.get_texture_desc(dt_rid)
                if dt_desc is not None:
                    depth_info["size"] = f"{dt_desc.width}x{dt_desc.height}"
                    depth_info["format"] = str(dt_desc.format.Name())
                saved.append(depth_info)
        except Exception as exc:
            saved.append({"type": "depth", "error": f"Failed to save depth: {exc}"})

    return {"event_id": event_id, "saved": saved, "count": len(saved)}


def export_mesh(
    event_id: int,
    output_path: str,
) -> dict:
    """Export mesh data from a draw call as OBJ format.

    Uses post-vertex-shader data to get transformed positions, normals, and UVs.

    Args:
        event_id: The event ID of the draw call.
        output_path: Output file path for the .obj file.
    """
    import struct as _struct

    session = get_session()
    err = session.require_open()
    if err:
        return err
    err = session.set_event(event_id)
    if err:
        return err

    postvs = session.controller.GetPostVSData(0, 0, rd.MeshDataStage.VSOut)
    if postvs.vertexResourceId == rd.ResourceId.Null():
        return make_error("No post-VS data available for this event", "API_ERROR")

    state = session.controller.GetPipelineState()
    vs_refl = state.GetShaderReflection(rd.ShaderStage.Vertex)
    if vs_refl is None:
        return make_error("No vertex shader bound", "API_ERROR")

    out_sig = vs_refl.outputSignature
    pos_idx = None
    norm_idx = None
    uv_idx = None
    float_offset = 0
    for sig in out_sig:
        name = (sig.semanticName or sig.varName or "").upper()
        if "POSITION" in name:
            pos_idx = float_offset
        elif "NORMAL" in name:
            norm_idx = float_offset
        elif "TEXCOORD" in name and uv_idx is None:
            uv_idx = float_offset
        float_offset += sig.compCount

    if pos_idx is None:
        pos_idx = 0

    num_verts = postvs.numIndices
    data = session.controller.GetBufferData(
        postvs.vertexResourceId,
        postvs.vertexByteOffset,
        num_verts * postvs.vertexByteStride,
    )

    floats_per_vertex = postvs.vertexByteStride // 4
    if floats_per_vertex == 0:
        return make_error(
            f"Invalid vertex stride ({postvs.vertexByteStride} bytes), cannot parse mesh data",
            "API_ERROR",
        )

    positions = []
    normals = []
    uvs = []
    for i in range(num_verts):
        off = i * postvs.vertexByteStride
        if off + postvs.vertexByteStride > len(data):
            break
        vfloats = list(_struct.unpack_from(f"{floats_per_vertex}f", data, off))

        if pos_idx is not None and pos_idx + 3 <= len(vfloats):
            positions.append(
                (vfloats[pos_idx], vfloats[pos_idx + 1], vfloats[pos_idx + 2])
            )
        else:
            positions.append((0.0, 0.0, 0.0))

        if norm_idx is not None and norm_idx + 3 <= len(vfloats):
            normals.append(
                (vfloats[norm_idx], vfloats[norm_idx + 1], vfloats[norm_idx + 2])
            )

        if uv_idx is not None and uv_idx + 2 <= len(vfloats):
            uvs.append((vfloats[uv_idx], vfloats[uv_idx + 1]))

    output_path = os.path.normpath(output_path)
    os.makedirs(os.path.dirname(output_path) or ".", exist_ok=True)

    try:
        topo = state.GetPrimitiveTopology()
        topo_name = enum_str(topo, TOPOLOGY_MAP, "Topology.")
    except Exception:
        topo_name = "TriangleList"

    lines = [f"# Exported from RenderDoc MCP - event {event_id}"]
    lines.append(f"# Vertices: {len(positions)}, Topology: {topo_name}")

    for p in positions:
        lines.append(f"v {p[0]:.6f} {p[1]:.6f} {p[2]:.6f}")

    for n in normals:
        lines.append(f"vn {n[0]:.6f} {n[1]:.6f} {n[2]:.6f}")

    for uv in uvs:
        lines.append(f"vt {uv[0]:.6f} {uv[1]:.6f}")

    has_normals = len(normals) == len(positions)
    has_uvs = len(uvs) == len(positions)
    triangles: list = []

    if topo_name == "TriangleStrip":
        for i in range(len(positions) - 2):
            if i % 2 == 0:
                triangles.append((i, i + 1, i + 2))
            else:
                triangles.append((i, i + 2, i + 1))
    elif topo_name == "TriangleFan":
        for i in range(1, len(positions) - 1):
            triangles.append((0, i, i + 1))
    else:
        for i in range(0, len(positions) - 2, 3):
            triangles.append((i, i + 1, i + 2))

    for t in triangles:
        i1, i2, i3 = t[0] + 1, t[1] + 1, t[2] + 1
        if has_normals and has_uvs:
            lines.append(f"f {i1}/{i1}/{i1} {i2}/{i2}/{i2} {i3}/{i3}/{i3}")
        elif has_normals:
            lines.append(f"f {i1}//{i1} {i2}//{i2} {i3}//{i3}")
        elif has_uvs:
            lines.append(f"f {i1}/{i1} {i2}/{i2} {i3}/{i3}")
        else:
            lines.append(f"f {i1} {i2} {i3}")

    with open(output_path, "w") as f:
        f.write("\n".join(lines) + "\n")

    return {
        "event_id": event_id,
        "output_path": output_path,
        "topology": topo_name,
        "vertices": len(positions),
        "normals": len(normals),
        "uvs": len(uvs),
        "triangles": len(triangles),
    }