import base64
from unittest.mock import AsyncMock

import pytest

from mcp_docugen.generation_store import GenerationStore
from mcp_docugen.llm_client import LLMResponse, OpenRouterClient
from mcp_docugen.models import TemplateFrontmatter, TemplateVariable
from mcp_docugen.renderer import (
    ImageTooLarge,
    InvalidImageEncoding,
    InvalidVariableType,
    MissingVariables,
    Renderer,
)
from mcp_docugen.template_store import TemplateStore


@pytest.fixture
async def env(tmp_path):
    template_store = TemplateStore(base_dir=tmp_path / "templates")
    generation_store = GenerationStore(
        db_path=tmp_path / "gen.db",
        generated_dir=tmp_path / "generated",
    )
    await generation_store.init()
    llm = AsyncMock(spec=OpenRouterClient)
    llm.chat.return_value = LLMResponse(
        text="# Output",
        model="anthropic/claude-sonnet-4",
        tokens_in=10,
        tokens_out=20,
        cost_usd=0.001,
        latency_ms=100,
    )
    renderer = Renderer(
        template_store=template_store,
        generation_store=generation_store,
        llm=llm,
        public_base_url="https://mcp.example.com",
        default_model="anthropic/claude-sonnet-4",
        asset_ttl_days=30,
        max_image_size_mb=10,
    )
    fm = TemplateFrontmatter(
        name="fattura",
        description="x",
        required_variables=[TemplateVariable(name="cliente", type="string")],
    )
    await template_store.create(
        name="fattura", frontmatter=fm, body="Cliente: {{cliente}}"
    )
    return renderer, llm


async def test_generate_happy_path_string_var(env):
    renderer, llm = env
    result = await renderer.generate(
        template_name="fattura",
        content_md="# Ordine",
        variables={"cliente": "ACME"},
        instructions=None,
    )
    assert result.markdown == "# Output"
    assert result.model == "anthropic/claude-sonnet-4"
    assert result.tokens.input == 10
    call_kwargs = llm.chat.await_args.kwargs
    assert "ACME" in call_kwargs["user"]
    assert "Cliente: ACME" in call_kwargs["system"]


async def test_generate_missing_required_variable_raises(env):
    renderer, _ = env
    with pytest.raises(MissingVariables) as exc:
        await renderer.generate(
            template_name="fattura",
            content_md="x",
            variables={},
            instructions=None,
        )
    assert "cliente" in str(exc.value)


async def test_generate_wrong_type_raises(env):
    renderer, _ = env
    with pytest.raises(InvalidVariableType):
        await renderer.generate(
            template_name="fattura",
            content_md="x",
            variables={
                "cliente": {
                    "kind": "image",
                    "data_b64": "x",
                    "mime": "image/png",
                }
            },
            instructions=None,
        )


async def test_generate_image_variable_is_saved_and_rewritten(tmp_path):
    template_store = TemplateStore(base_dir=tmp_path / "templates")
    generation_store = GenerationStore(
        db_path=tmp_path / "gen.db",
        generated_dir=tmp_path / "generated",
    )
    await generation_store.init()
    llm = AsyncMock(spec=OpenRouterClient)
    llm.chat.return_value = LLMResponse(
        text="# OK", model="m", tokens_in=1, tokens_out=1, cost_usd=0, latency_ms=10
    )
    renderer = Renderer(
        template_store=template_store,
        generation_store=generation_store,
        llm=llm,
        public_base_url="https://mcp.example.com",
        default_model="m",
        asset_ttl_days=30,
        max_image_size_mb=10,
    )
    fm = TemplateFrontmatter(
        name="report",
        description="x",
        required_variables=[TemplateVariable(name="foto", type="image")],
    )
    await template_store.create(name="report", frontmatter=fm, body="![foto]({{foto}})")

    png = b"\x89PNG\r\n\x1a\n" + b"\x00" * 100
    img_var = {
        "kind": "image",
        "data_b64": base64.b64encode(png).decode(),
        "mime": "image/png",
    }
    result = await renderer.generate(
        template_name="report",
        content_md="content",
        variables={"foto": img_var},
        instructions=None,
    )

    assert result.ephemeral_assets_urls
    url = result.ephemeral_assets_urls[0]
    assert url.startswith("https://mcp.example.com/generated/")
    assert url.endswith(".png")
    gen_dir = tmp_path / "generated" / result.generation_id
    assert gen_dir.exists()
    assert any(gen_dir.iterdir())

    call_kwargs = llm.chat.await_args.kwargs
    assert "https://mcp.example.com/generated/" in call_kwargs["system"]


async def test_image_too_large_raises(env):
    renderer, _ = env
    big = b"x" * (11 * 1024 * 1024)
    img_var = {
        "kind": "image",
        "data_b64": base64.b64encode(big).decode(),
        "mime": "image/png",
    }
    fm = TemplateFrontmatter(
        name="big",
        description="x",
        required_variables=[TemplateVariable(name="foto", type="image")],
    )
    await renderer.template_store.create(name="big", frontmatter=fm, body="{{foto}}")
    with pytest.raises(ImageTooLarge):
        await renderer.generate(
            template_name="big",
            content_md="x",
            variables={"foto": img_var},
            instructions=None,
        )


async def test_invalid_base64_raises(env):
    renderer, _ = env
    fm = TemplateFrontmatter(
        name="bad",
        description="x",
        required_variables=[TemplateVariable(name="foto", type="image")],
    )
    await renderer.template_store.create(name="bad", frontmatter=fm, body="{{foto}}")
    with pytest.raises(InvalidImageEncoding):
        await renderer.generate(
            template_name="bad",
            content_md="x",
            variables={
                "foto": {
                    "kind": "image",
                    "data_b64": "!!!not-base64!!!",
                    "mime": "image/png",
                }
            },
            instructions=None,
        )


async def test_template_asset_paths_are_rewritten(tmp_path):
    template_store = TemplateStore(base_dir=tmp_path / "templates")
    generation_store = GenerationStore(
        db_path=tmp_path / "gen.db",
        generated_dir=tmp_path / "generated",
    )
    await generation_store.init()
    llm = AsyncMock(spec=OpenRouterClient)
    llm.chat.return_value = LLMResponse(
        text="out", model="m", tokens_in=1, tokens_out=1, cost_usd=0, latency_ms=10
    )
    renderer = Renderer(
        template_store=template_store,
        generation_store=generation_store,
        llm=llm,
        public_base_url="https://mcp.example.com",
        default_model="m",
        asset_ttl_days=30,
        max_image_size_mb=10,
    )
    fm = TemplateFrontmatter(name="brand", description="x")
    assets = [
        {
            "filename": "logo.png",
            "data_b64": base64.b64encode(b"\x89PNG").decode(),
            "mime": "image/png",
        }
    ]
    await template_store.create(
        name="brand",
        frontmatter=fm,
        body="Header ![logo](./assets/logo.png) footer",
        assets=assets,
    )
    await renderer.generate(
        template_name="brand",
        content_md="x",
        variables={},
        instructions=None,
    )
    system_prompt = llm.chat.await_args.kwargs["system"]
    assert "https://mcp.example.com/assets/brand/logo.png" in system_prompt
    assert "./assets/logo.png" not in system_prompt


async def test_generate_uses_frontmatter_model_override(tmp_path):
    template_store = TemplateStore(base_dir=tmp_path / "templates")
    generation_store = GenerationStore(
        db_path=tmp_path / "gen.db",
        generated_dir=tmp_path / "generated",
    )
    await generation_store.init()
    llm = AsyncMock(spec=OpenRouterClient)
    llm.chat.return_value = LLMResponse(
        text="out",
        model="openai/gpt-4o",
        tokens_in=1,
        tokens_out=1,
        cost_usd=0,
        latency_ms=10,
    )
    renderer = Renderer(
        template_store=template_store,
        generation_store=generation_store,
        llm=llm,
        public_base_url="https://mcp.example.com",
        default_model="anthropic/claude-sonnet-4",
        asset_ttl_days=30,
        max_image_size_mb=10,
    )
    fm = TemplateFrontmatter(name="x", description="y", model="openai/gpt-4o")
    await template_store.create(name="x", frontmatter=fm, body="b")
    await renderer.generate(
        template_name="x", content_md="c", variables={}, instructions=None
    )
    assert llm.chat.await_args.kwargs["model"] == "openai/gpt-4o"