from __future__ import annotations

import uuid

from fastapi import APIRouter, Depends, HTTPException
from pydantic import BaseModel, Field

from auth import require_admin_dep, require_auth
from db import get_db, row_to_dict
from engine import EngineError, execute_prompt, preview_prompt

router = APIRouter(prefix="/api/prompts", tags=["prompts"])

LIST_FIELDS = """
id, slug, name, description, category, prompt_type, template, required_feature,
active, is_system_default, sort_order, created, updated
"""


class PromptWrite(BaseModel):
    slug: str = Field(min_length=1, max_length=80)
    name: str = Field(min_length=1)
    description: str = ""
    category: str = "uncategorized"
    prompt_type: str = "base"
    template: str = ""
    required_feature: str = "ai_calls"
    active: bool = True


class PreviewRequest(BaseModel):
    slug: str | None = None
    prompt_id: str | None = None


class ExecuteRequest(BaseModel):
    slug: str | None = None
    prompt_id: str | None = None
    purpose: str = "reflection"
    data_class: str = Field(default="B")


def _http(exc: EngineError):
    raise HTTPException(status_code=exc.status_code, detail={"code": exc.code, "message": exc.message}) from exc


def _load(conn, prompt_id: str | None, slug: str | None) -> dict:
    if prompt_id:
        row = conn.execute("SELECT * FROM ai_prompts WHERE id = ?", (prompt_id,)).fetchone()
    elif slug:
        row = conn.execute("SELECT * FROM ai_prompts WHERE slug = ?", (slug,)).fetchone()
    else:
        raise HTTPException(400, "prompt_id oder slug ist erforderlich")
    prompt = row_to_dict(row)
    if not prompt:
        raise HTTPException(404, "Prompt nicht gefunden")
    return prompt


@router.get("")
def list_prompts(session: dict = Depends(require_admin_dep)):
    with get_db() as conn:
        rows = conn.execute(f"SELECT {LIST_FIELDS} FROM ai_prompts ORDER BY sort_order, name").fetchall()
    return [row_to_dict(row) for row in rows]


@router.post("")
def create_prompt(req: PromptWrite, session: dict = Depends(require_admin_dep)):
    if req.prompt_type not in {"base", "pipeline", "workflow"}:
        raise HTTPException(400, "Ungültiger Prompt-Typ")
    prompt_id = str(uuid.uuid4())
    if req.prompt_type == "base" and req.template:
        try:
            preview_prompt(
                {
                    "id": prompt_id,
                    "slug": req.slug.strip(),
                    "prompt_type": req.prompt_type,
                    "template": req.template,
                },
                {},
            )
        except EngineError as exc:
            _http(exc)
    try:
        with get_db() as conn:
            conn.execute(
                """
                INSERT INTO ai_prompts
                  (id, slug, name, description, category, prompt_type, template,
                   required_feature, active, default_template)
                VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
                """,
                (
                    prompt_id,
                    req.slug.strip(),
                    req.name.strip(),
                    req.description,
                    req.category.strip() or "uncategorized",
                    req.prompt_type,
                    req.template,
                    req.required_feature,
                    1 if req.active else 0,
                    req.template,
                ),
            )
            return row_to_dict(conn.execute(f"SELECT {LIST_FIELDS} FROM ai_prompts WHERE id = ?", (prompt_id,)).fetchone())
    except Exception as exc:
        if "UNIQUE" in str(exc).upper():
            raise HTTPException(409, "Slug ist bereits vergeben") from exc
        raise


@router.put("/{prompt_id}")
def update_prompt(prompt_id: str, req: PromptWrite, session: dict = Depends(require_admin_dep)):
    with get_db() as conn:
        current = row_to_dict(conn.execute("SELECT id FROM ai_prompts WHERE id = ?", (prompt_id,)).fetchone())
        if not current:
            raise HTTPException(404, "Prompt nicht gefunden")
        if req.prompt_type == "base" and req.template:
            try:
                preview_prompt(
                    {
                        "id": prompt_id,
                        "slug": req.slug.strip(),
                        "prompt_type": req.prompt_type,
                        "template": req.template,
                    },
                    {},
                )
            except EngineError as exc:
                _http(exc)
        conn.execute(
            """
            UPDATE ai_prompts
            SET slug = ?, name = ?, description = ?, category = ?, prompt_type = ?,
                template = ?, required_feature = ?, active = ?, updated = datetime('now')
            WHERE id = ?
            """,
            (
                req.slug.strip(),
                req.name.strip(),
                req.description,
                req.category.strip() or "uncategorized",
                req.prompt_type,
                req.template,
                req.required_feature,
                1 if req.active else 0,
                prompt_id,
            ),
        )
        return row_to_dict(conn.execute(f"SELECT {LIST_FIELDS} FROM ai_prompts WHERE id = ?", (prompt_id,)).fetchone())


@router.post("/{prompt_id}/reset")
def reset_prompt(prompt_id: str, session: dict = Depends(require_admin_dep)):
    with get_db() as conn:
        prompt = row_to_dict(conn.execute("SELECT * FROM ai_prompts WHERE id = ?", (prompt_id,)).fetchone())
        if not prompt:
            raise HTTPException(404, "Prompt nicht gefunden")
        if not prompt["is_system_default"]:
            raise HTTPException(400, "Nur System-Defaults können zurückgesetzt werden")
        conn.execute(
            "UPDATE ai_prompts SET template = default_template, updated = datetime('now') WHERE id = ?",
            (prompt_id,),
        )
        return row_to_dict(conn.execute(f"SELECT {LIST_FIELDS} FROM ai_prompts WHERE id = ?", (prompt_id,)).fetchone())


@router.post("/preview")
def preview(req: PreviewRequest, session: dict = Depends(require_admin_dep)):
    with get_db() as conn:
        prompt = _load(conn, req.prompt_id, req.slug)
    try:
        return preview_prompt(prompt, {"profile_id": session["profile_id"]})
    except EngineError as exc:
        _http(exc)


@router.post("/execute")
def execute(req: ExecuteRequest, session: dict = Depends(require_auth)):
    with get_db() as conn:
        prompt = _load(conn, req.prompt_id, req.slug)
        if not prompt["active"] and session.get("role") != "admin":
            raise HTTPException(404, "Prompt nicht gefunden")
    try:
        return execute_prompt(
            prompt,
            profile_id=session["profile_id"],
            purpose=req.purpose,
            data_class=req.data_class,
            context={"profile_id": session["profile_id"]},
        )
    except EngineError as exc:
        _http(exc)