from __future__ import annotations

import json
import re
from datetime import datetime
from enum import Enum
from typing import Any, Literal

from pydantic import BaseModel, ConfigDict, Field, field_validator, model_validator

PROJECT_NAME_MAX_LENGTH = 200
PROJECT_DESCRIPTION_MAX_LENGTH = 4000
PROJECT_METADATA_MAX_BYTES = 16 * 1024


class ProjectStatus(str, Enum):
    ACTIVE = "active"
    ARCHIVED = "archived"


def normalize_project_name(value: str) -> str:
    normalized = re.sub(r"\s+", " ", value).strip()
    if not normalized:
        raise ValueError("Project name cannot be blank")
    if len(normalized) > PROJECT_NAME_MAX_LENGTH:
        raise ValueError(f"Project name cannot exceed {PROJECT_NAME_MAX_LENGTH} characters")
    return normalized


def validate_metadata_size(value: dict[str, Any]) -> dict[str, Any]:
    try:
        encoded = json.dumps(
            value, ensure_ascii=False, separators=(",", ":"), allow_nan=False
        ).encode("utf-8")
    except (TypeError, ValueError) as exc:
        raise ValueError("Project metadata must be valid JSON") from exc
    if len(encoded) > PROJECT_METADATA_MAX_BYTES:
        raise ValueError(f"Project metadata cannot exceed {PROJECT_METADATA_MAX_BYTES} bytes")
    return value


class ProjectCreate(BaseModel):
    model_config = ConfigDict(extra="forbid")

    name: str
    description: str | None = Field(default=None, max_length=PROJECT_DESCRIPTION_MAX_LENGTH)
    thumbnail_asset_id: str | None = Field(default=None, min_length=1, max_length=36)
    metadata: dict[str, Any] = Field(default_factory=dict)

    _normalize_name = field_validator("name")(normalize_project_name)
    _validate_metadata = field_validator("metadata")(validate_metadata_size)


class ProjectUpdate(BaseModel):
    model_config = ConfigDict(extra="forbid")

    name: str | None = None
    description: str | None = Field(default=None, max_length=PROJECT_DESCRIPTION_MAX_LENGTH)
    thumbnail_asset_id: str | None = Field(default=None, min_length=1, max_length=36)
    metadata: dict[str, Any] | None = None
    status: ProjectStatus | None = None

    @field_validator("name")
    @classmethod
    def normalize_name(cls, value: str | None) -> str | None:
        if value is None:
            return value
        return normalize_project_name(value)

    @field_validator("metadata")
    @classmethod
    def validate_metadata(cls, value: dict[str, Any] | None) -> dict[str, Any] | None:
        return None if value is None else validate_metadata_size(value)

    @model_validator(mode="after")
    def validate_patch(self) -> ProjectUpdate:
        if not self.model_fields_set:
            raise ValueError("At least one project field must be supplied")
        if "name" in self.model_fields_set and self.name is None:
            raise ValueError("Project name cannot be null")
        if "metadata" in self.model_fields_set and self.metadata is None:
            raise ValueError("Project metadata cannot be null")
        if "status" in self.model_fields_set and self.status is None:
            raise ValueError("Project status cannot be null")
        return self


class ProjectResponse(BaseModel):
    model_config = ConfigDict(from_attributes=True)

    id: str
    workspace_id: str
    name: str
    description: str | None
    status: ProjectStatus
    thumbnail_asset_id: str | None
    brand_kit_id: str | None = None
    brand_kit_version_id: str | None = None
    metadata: dict[str, Any]
    created_by: str
    created_at: datetime
    updated_at: datetime
    archived_at: datetime | None


class ProjectListResponse(BaseModel):
    items: list[ProjectResponse]
    next_cursor: str | None = None
    limit: int = Field(ge=1, le=100)


class ProjectAssetAttach(BaseModel):
    model_config = ConfigDict(extra="forbid")

    asset_id: str = Field(min_length=1, max_length=36)


class ProjectAssetResponse(BaseModel):
    id: str
    project_id: str
    request_id: str
    filename: str
    mime_type: str
    file_size: int
    metadata: dict[str, Any]
    created_by_user_id: str | None
    created_at: datetime
    updated_at: datetime


class ProjectAssetListResponse(BaseModel):
    items: list[ProjectAssetResponse]


class ProjectGenerationJobAttach(BaseModel):
    model_config = ConfigDict(extra="forbid")

    generation_job_id: str = Field(min_length=1, max_length=36)


class ProjectGenerationJobResponse(BaseModel):
    id: str
    project_id: str
    job_type: Literal["generation"] = "generation"
    generation_request_id: str
    provider: str
    status: str
    output_asset_id: str | None
    error_code: str | None
    created_at: datetime
    started_at: datetime | None
    completed_at: datetime | None
    updated_at: datetime
    attached_at: datetime


class ProjectGenerationJobListResponse(BaseModel):
    items: list[ProjectGenerationJobResponse]