import os
import enum
from collections import namedtuple
import torch
from modules import hashes, shared, sd_checkpoint


NetworkWeights = namedtuple('NetworkWeights', ['network_key', 'sd_key', 'w', 'sd_module'])
metadata_tags_order = {"ss_sd_model_name": 1, "ss_resolution": 2, "ss_clip_skip": 3, "ss_num_train_images": 10, "ss_tag_frequency": 20}


class SdVersion(enum.Enum):
    Unknown = 1
    SD1 = 2
    SD2 = 3
    SD3 = 3
    SDXL = 4
    SC = 5
    F1 = 6
    HV = 7
    CHROMA = 8


class NetworkOnDisk:
    def __init__(self, name, filename):
        self.shorthash = None
        self.hash = None
        self.name = name
        self.filename = filename
        if filename.startswith(shared.cmd_opts.lora_dir):
            # strip("/") missed Windows's leading backslash after the slice; normalize separators
            # so the registry key is one canonical form on every OS.
            rel = filename[len(shared.cmd_opts.lora_dir):].lstrip('/\\').replace('\\', '/')
            self.fullname = os.path.splitext(rel)[0] if rel else name
        else:
            self.fullname = name
        self.metadata = {}
        self.is_safetensors = os.path.splitext(filename)[1].lower() == ".safetensors"
        if self.is_safetensors:
            self.metadata = sd_checkpoint.read_metadata_from_safetensors(filename)
        if self.metadata:
            m = {}
            for k, v in sorted(self.metadata.items(), key=lambda x: metadata_tags_order.get(x[0], 999)):
                m[k] = v
            self.metadata = m
        self.alias = self.metadata.get('ss_output_name', self.name)
        sha256 = hashes.sha256_from_cache(self.filename, "lora/" + self.name) or hashes.sha256_from_cache(self.filename, "lora/" + self.name, store='hashes-addnet') or self.metadata.get('sshs_model_hash')
        self.set_hash(sha256)
        self.sd_version = self.detect_version()

    def __str__(self):
        return f"NetworkOnDisk(name={self.name} filename={self.filename}"

    def detect_version(self):
        base = str(self.metadata.get('ss_base_model_version', "")).lower()
        arch = str(self.metadata.get('modelspec.architecture', "")).lower()
        if base.startswith("sd_v1"):
            return 'sd1'
        if base.startswith("sdxl"):
            return 'xl'
        if base.startswith("stable_cascade"):
            return 'sc'
        if base.startswith("sd3"):
            return 'sd3'
        if base.startswith("flux2") or "klein" in base:
            return 'f2'
        if base.startswith("flux"):
            return 'f1'
        if base.startswith("hunyuan_video"):
            return 'hv'
        if base.startswith("chroma"):
            return 'chroma'
        if base.startswith('zimage'):
            return 'zimage'
        if base.startswith('anima'):
            return 'anima'
        if base.startswith('qwen'):
            return 'qwen'

        if arch.startswith("stable-diffusion-v1"):
            return 'sd1'
        if arch.startswith("stable-diffusion-xl"):
            return 'xl'
        if arch.startswith("stable-cascade"):
            return 'sc'
        if arch.startswith("flux2") or "klein" in arch:
            return 'f2'
        if arch.startswith("flux"):
            return 'f1'
        if arch.startswith("hunyuan-video"):
            return 'hv'
        if arch.startswith("chroma"):
            return 'chroma'

        if "v1-5" in str(self.metadata.get('ss_sd_model_name', "")):
            return 'sd1'
        if str(self.metadata.get('ss_v2', "")) == "True":
            return 'sd2'
        if 'klein' in self.name.lower() or 'klein' in self.fullname.lower():
            return 'f2'
        if 'flux' in self.name.lower():
            return 'f1'
        if 'xl' in self.name.lower():
            return 'xl'
        if 'chroma' in self.name.lower():
            return 'chroma'
        if 'anima' in self.name.lower():
            return 'anima'

        return ''

    def set_hash(self, v):
        self.hash = v or ''
        self.shorthash = self.hash[0:8]

    def read_hash(self):
        if not self.hash:
            self.set_hash(hashes.sha256(self.filename, "lora/" + self.name, store='hashes-addnet' if self.is_safetensors else None) or '')

    def get_info(self):
        data = {}
        if shared.cmd_opts.no_metadata:
            return data
        if self.filename is not None:
            fn = os.path.splitext(self.filename)[0] + '.json'
            if os.path.exists(fn):
                data = shared.readfile(fn, silent=True, as_type="dict")
        return data

    def get_desc(self):
        if shared.cmd_opts.no_metadata:
            return None
        if self.filename is not None:
            fn = os.path.splitext(self.filename)[0] + '.txt'
            if os.path.exists(fn):
                with open(fn, encoding="utf-8") as file:
                    return file.read()
        return None

    def get_alias(self):
        return self.name


class Network:  # LoraModule
    def __init__(self, name, network_on_disk: NetworkOnDisk):
        self.name = name
        self.network_on_disk = network_on_disk
        self.te_multiplier = 1.0
        self.unet_multiplier = [1.0] * 3
        self.dyn_dim = None
        self.pending_config = None # staged multipliers; network_activate promotes them after the removal pass so fuse removal subtracts the delta that was applied
        self.modules = {}
        self.mismatch = 0 # deltas dropped for not fitting their target module; try_load_chain refuses the file when non-zero
        self.bundle_embeddings = {}
        self.mtime = None
        self.mentioned_name = None
        self.tags = None
        """the text that was used to add the network to prompt - can be either name or an alias"""


class ModuleType:
    def create_module(self, net: Network, weights: NetworkWeights) -> Network | None: # pylint: disable=W0613
        return None


class NetworkModule:
    def __init__(self, net: Network, weights: NetworkWeights):
        self.network = net
        self.network_key = weights.network_key
        self.sd_key = weights.sd_key
        self.sd_module = weights.sd_module
        self.shape = None
        if hasattr(self.sd_module, 'weight'):
            if hasattr(self.sd_module, "sdnq_dequantizer"):
                self.shape = self.sd_module.sdnq_dequantizer.original_shape
            else:
                self.shape = self.sd_module.weight.shape
        self.dim = None
        self.bias = weights.w.get("bias")
        if self.bias is None and "bias_indices" in weights.w:
            # LyCORIS extraction with use_bias: the sparse weight-shaped
            # remainder of the SVD extraction ("bias" is historical naming),
            # stored COO with int16 indices. Kept sparse; finalize_updown's
            # dense += sparse materializes it per module at apply time.
            self.bias = torch.sparse_coo_tensor(
                weights.w["bias_indices"].to(torch.long),
                weights.w["bias_values"],
                tuple(weights.w["bias_size"]),
            )
        self.alpha = weights.w["alpha"].item() if "alpha" in weights.w else None
        self.scale = weights.w["scale"].item() if "scale" in weights.w else None
        self.dora_scale = weights.w.get("dora_scale", None)
        self.dora_norm_dims = (len(self.shape) - 1) if self.shape is not None else None

    def multiplier(self):
        unet_multiplier = 3 * [self.network.unet_multiplier] if not isinstance(self.network.unet_multiplier, list) else self.network.unet_multiplier
        if self.sd_key.startswith('lora_te') or 'transformer' in self.sd_key[:20]:
            return self.network.te_multiplier
        if "down_blocks" in self.sd_key:
            return unet_multiplier[0]
        if "mid_block" in self.sd_key:
            return unet_multiplier[1]
        if "up_blocks" in self.sd_key:
            return unet_multiplier[2]
        else:
            return unet_multiplier[0]

    def calc_scale(self):
        if self.scale is not None:
            return self.scale
        if self.dim is not None and self.alpha is not None:
            return self.alpha / self.dim
        return 1.0

    def apply_weight_decompose(self, updown, orig_weight):
        # Match the device/dtype
        orig_weight = orig_weight.to(updown.dtype)
        dora_scale = self.dora_scale.to(device=orig_weight.device, dtype=updown.dtype)
        updown = updown.to(orig_weight.device)

        merged_scale1 = updown + orig_weight

        # DoRA convention detection. Two flavors coexist in the wild:
        #
        # - per-input (DoRA paper / kohya): dora_scale stores per-column magnitudes,
        #   shape ``(1, in, ...)`` or ``(in,)``. ``W' = W * (m / ||W||_col)`` rescales
        #   each column to magnitude ``m[i]``.
        # - per-output (LyCORIS / PEFT / diffusers): dora_scale stores per-row
        #   magnitudes, shape ``(out, 1, ...)`` or ``(out,)``. ``W' = W * (m / ||W||_row)``
        #   rescales each row to magnitude ``m[o]``.
        #
        # PyTorch silently broadcasts ``(out, 1) / (1, in)`` into ``(out, in)``, so
        # mismatched conventions are not a shape error but a semantic one (the
        # update gets scrambled). Detection is structural rather than numeric:
        # a 2-D dora_scale with shape ``(out, 1, ...)`` is unambiguously per-output
        # even when ``out == in`` (square weights like self-attention q/k/v).
        # 1-D dora_scale falls back to comparing the length against out / in;
        # when both match (square weight), default to per-input for legacy compat.
        out_dim = merged_scale1.shape[0]
        in_dim = merged_scale1.shape[1] if merged_scale1.ndim >= 2 else None
        per_output = False
        if dora_scale.ndim >= 2:
            # ND form: leading dim equals out_dim and every trailing dim is 1.
            if dora_scale.shape[0] == out_dim and all(d == 1 for d in dora_scale.shape[1:]):
                per_output = True
        elif dora_scale.ndim == 1:
            # 1D vector: per-output only when length unambiguously matches out_dim.
            if dora_scale.shape[0] == out_dim and dora_scale.shape[0] != in_dim:
                per_output = True

        if per_output:
            # Per-output: norm along all non-output axes; result broadcasts as (out, 1, ...).
            merged_scale1_norm = (
                merged_scale1.reshape(out_dim, -1)
                .norm(dim=1, keepdim=True)
                .reshape(out_dim, *[1] * self.dora_norm_dims)
            )
        else:
            # Per-input: norm along all non-input axes; result broadcasts as (1, in, ...).
            merged_scale1_norm = (
                merged_scale1.transpose(0, 1)
                .reshape(merged_scale1.shape[1], -1)
                .norm(dim=1, keepdim=True)
                .reshape(merged_scale1.shape[1], *[1] * self.dora_norm_dims)
                .transpose(0, 1)
            )

        dora_merged = merged_scale1 * (dora_scale / merged_scale1_norm)
        final_updown = dora_merged - orig_weight
        return final_updown

    def finalize_updown(self, updown, orig_weight, output_shape, ex_bias=None):
        if self.bias is not None:
            updown = updown.reshape(self.bias.shape)
            updown += self.bias.to(orig_weight.device, dtype=orig_weight.dtype)
            updown = updown.reshape(output_shape)
        if len(output_shape) == 4:
            updown = updown.reshape(output_shape)
        if orig_weight.size().numel() == updown.size().numel():
            updown = updown.reshape(orig_weight.shape)
        if ex_bias is not None:
            ex_bias = ex_bias * self.multiplier()
        if self.dora_scale is not None:
            # LyCORIS/ComfyUI convention: alpha/rank is baked into the diff
            # before the decompose norm. The multiplier then lerps the full
            # merged delta (ComfyUI semantics: 0 disables, 1 equals the
            # trainer's output; LyCORIS weight-mode ratio interpolation is
            # not used since it leaves the diff applied at multiplier 0).
            updown = self.apply_weight_decompose(updown * self.calc_scale(), orig_weight)
            return updown * self.multiplier(), ex_bias
        return updown * self.calc_scale() * self.multiplier(), ex_bias

    def calc_updown(self, target):
        raise NotImplementedError

    def forward(self, x, y):
        raise NotImplementedError