#!/usr/bin/env python3
"""
Agent Marketplace API
=====================
REST API for the agent template marketplace.

Endpoints:
- /marketplace/templates - Browse and search templates
- /marketplace/templates/{id} - Get template details
- /marketplace/publish - Publish new template
- /marketplace/install - Install template to project
- /marketplace/ratings - Rate and review templates
"""

import hashlib
import json
import os
import re
import secrets
import sqlite3
from datetime import datetime, timezone
from pathlib import Path
from typing import Optional, List
from contextlib import contextmanager

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

# =============================================================================
# Configuration
# =============================================================================

DB_PATH = Path("/opt/agent-governance/ledger/governance.db")
TEMPLATE_STORAGE = Path("/opt/agent-governance/marketplace/templates")
TEMPLATE_STORAGE.mkdir(parents=True, exist_ok=True)

# =============================================================================
# Database
# =============================================================================

@contextmanager
def get_db():
    conn = sqlite3.connect(DB_PATH)
    conn.row_factory = sqlite3.Row
    try:
        yield conn
    finally:
        conn.close()


def row_to_dict(row: sqlite3.Row) -> dict:
    return dict(row)


def rows_to_list(rows: list) -> list:
    return [row_to_dict(row) for row in rows]


# =============================================================================
# Models
# =============================================================================

class TenantContext(BaseModel):
    """Simplified tenant context for marketplace"""
    tenant_id: str = "default"
    project_id: str = "default"
    user_id: Optional[str] = None
    role: str = "viewer"


class TemplateCreate(BaseModel):
    name: str
    slug: str
    description: Optional[str] = None
    category: str = "general"
    tier_required: int = 0
    is_public: bool = False
    license: str = "MIT"
    repository_url: Optional[str] = None
    documentation_url: Optional[str] = None
    tags: List[str] = []
    capabilities: List[str] = []
    requirements: Optional[dict] = None


class TemplateVersionCreate(BaseModel):
    version: str  # Semantic version: 1.0.0
    release_notes: Optional[str] = None
    config_schema: Optional[dict] = None
    template_content: dict  # Full template definition
    is_stable: bool = True


class TemplateInstall(BaseModel):
    template_id: str
    version: Optional[str] = None  # None = latest
    config_overrides: Optional[dict] = None


class TemplateRating(BaseModel):
    rating: int = Field(ge=1, le=5)
    review_title: Optional[str] = None
    review_text: Optional[str] = None


class TemplateUpdate(BaseModel):
    name: Optional[str] = None
    description: Optional[str] = None
    category: Optional[str] = None
    is_public: Optional[bool] = None
    tags: Optional[List[str]] = None
    capabilities: Optional[List[str]] = None


# =============================================================================
# Helper Functions
# =============================================================================

def parse_version(version: str) -> int:
    """Convert semver to sortable integer: 1.2.3 -> 10203"""
    parts = version.split(".")
    if len(parts) != 3:
        return 0
    try:
        major, minor, patch = int(parts[0]), int(parts[1]), int(parts[2])
        return major * 10000 + minor * 100 + patch
    except ValueError:
        return 0


def validate_slug(slug: str) -> bool:
    """Validate slug format: lowercase, alphanumeric, hyphens only"""
    return bool(re.match(r'^[a-z0-9][a-z0-9-]*[a-z0-9]$', slug)) or len(slug) == 1


def update_template_stats(conn, template_id: str, stat: str, increment: int = 1):
    """Update template statistics"""
    conn.execute(f"""
        INSERT INTO template_stats (template_id, {stat}, updated_at)
        VALUES (?, ?, datetime('now'))
        ON CONFLICT(template_id) DO UPDATE SET
        {stat} = {stat} + ?,
        updated_at = datetime('now')
    """, (template_id, increment, increment))


def calculate_avg_rating(conn, template_id: str):
    """Recalculate average rating for template"""
    cursor = conn.execute("""
        SELECT AVG(rating) as avg, COUNT(*) as count
        FROM template_ratings WHERE template_id = ?
    """, (template_id,))
    row = cursor.fetchone()

    conn.execute("""
        UPDATE template_stats
        SET avg_rating = ?, rating_count = ?, updated_at = datetime('now')
        WHERE template_id = ?
    """, (row["avg"] or 0, row["count"], template_id))


# =============================================================================
# Router
# =============================================================================

router = APIRouter(prefix="/marketplace", tags=["Marketplace"])


# =============================================================================
# Browse & Search Endpoints
# =============================================================================

@router.get("/templates")
async def list_templates(
    category: Optional[str] = None,
    tag: Optional[str] = None,
    search: Optional[str] = None,
    author: Optional[str] = None,
    verified_only: bool = False,
    sort: str = Query("popular", pattern="^(popular|recent|rating|downloads)$"),
    limit: int = Query(20, le=100),
    offset: int = Query(0, ge=0)
):
    """List and search marketplace templates"""
    with get_db() as conn:
        # Use FTS for search, regular query otherwise
        if search:
            cursor = conn.execute("""
                SELECT t.*, ts.total_downloads, ts.avg_rating, ts.rating_count,
                       ts.trending_score
                FROM agent_templates t
                LEFT JOIN template_stats ts ON t.template_id = ts.template_id
                WHERE t.template_id IN (
                    SELECT template_id FROM template_search WHERE template_search MATCH ?
                )
                AND t.is_public = 1
                ORDER BY ts.trending_score DESC
                LIMIT ? OFFSET ?
            """, (search, limit, offset))
        else:
            query = """
                SELECT t.*, ts.total_downloads, ts.avg_rating, ts.rating_count,
                       ts.trending_score
                FROM agent_templates t
                LEFT JOIN template_stats ts ON t.template_id = ts.template_id
                WHERE t.is_public = 1
            """
            params = []

            if category:
                query += " AND t.category = ?"
                params.append(category)
            if tag:
                query += " AND t.tags LIKE ?"
                params.append(f'%"{tag}"%')
            if author:
                query += " AND t.author_id = ?"
                params.append(author)
            if verified_only:
                query += " AND t.is_verified = 1"

            # Sorting
            sort_map = {
                "popular": "ts.trending_score DESC",
                "recent": "t.created_at DESC",
                "rating": "ts.avg_rating DESC",
                "downloads": "ts.total_downloads DESC"
            }
            query += f" ORDER BY {sort_map.get(sort, 'ts.trending_score DESC')}"
            query += " LIMIT ? OFFSET ?"
            params.extend([limit, offset])

            cursor = conn.execute(query, params)

        templates = rows_to_list(cursor.fetchall())

        # Parse JSON fields
        for t in templates:
            t["tags"] = json.loads(t["tags"]) if t.get("tags") else []
            t["capabilities"] = json.loads(t["capabilities"]) if t.get("capabilities") else []

    return {"templates": templates, "count": len(templates)}


@router.get("/templates/{template_id}")
async def get_template(template_id: str):
    """Get template details with versions"""
    with get_db() as conn:
        # Get template
        cursor = conn.execute("""
            SELECT t.*, ts.total_downloads, ts.avg_rating, ts.rating_count,
                   ts.active_installs, ts.trending_score
            FROM agent_templates t
            LEFT JOIN template_stats ts ON t.template_id = ts.template_id
            WHERE t.template_id = ?
        """, (template_id,))
        template = cursor.fetchone()

        if not template:
            raise HTTPException(status_code=404, detail="Template not found")

        template = row_to_dict(template)
        template["tags"] = json.loads(template["tags"]) if template.get("tags") else []
        template["capabilities"] = json.loads(template["capabilities"]) if template.get("capabilities") else []
        template["requirements"] = json.loads(template["requirements"]) if template.get("requirements") else {}

        # Get versions
        cursor = conn.execute("""
            SELECT version_id, version, version_number, release_notes,
                   is_stable, is_deprecated, published_at
            FROM template_versions
            WHERE template_id = ?
            ORDER BY version_number DESC
        """, (template_id,))
        template["versions"] = rows_to_list(cursor.fetchall())

        # Get recent ratings
        cursor = conn.execute("""
            SELECT rating, review_title, review_text, created_at
            FROM template_ratings
            WHERE template_id = ?
            ORDER BY created_at DESC
            LIMIT 5
        """, (template_id,))
        template["recent_reviews"] = rows_to_list(cursor.fetchall())

    return template


@router.get("/templates/{template_id}/versions/{version}")
async def get_template_version(template_id: str, version: str):
    """Get specific version of a template with full content"""
    with get_db() as conn:
        cursor = conn.execute("""
            SELECT * FROM template_versions
            WHERE template_id = ? AND version = ?
        """, (template_id, version))
        ver = cursor.fetchone()

        if not ver:
            raise HTTPException(status_code=404, detail="Version not found")

        ver = row_to_dict(ver)
        ver["config_schema"] = json.loads(ver["config_schema"]) if ver.get("config_schema") else {}
        ver["template_content"] = json.loads(ver["template_content"]) if ver.get("template_content") else {}

    return ver


@router.get("/categories")
async def list_categories():
    """List marketplace categories"""
    with get_db() as conn:
        cursor = conn.execute("""
            SELECT c.*, COUNT(t.template_id) as template_count
            FROM marketplace_categories c
            LEFT JOIN agent_templates t ON c.category_id = t.category AND t.is_public = 1
            WHERE c.is_active = 1
            GROUP BY c.category_id
            ORDER BY c.sort_order
        """)
        categories = rows_to_list(cursor.fetchall())

    return {"categories": categories}


# =============================================================================
# Publishing Endpoints
# =============================================================================

@router.post("/templates")
async def create_template(
    template: TemplateCreate,
    ctx: TenantContext = None
):
    """Create a new template (publish to marketplace)"""
    if ctx is None:
        ctx = TenantContext()

    if not validate_slug(template.slug):
        raise HTTPException(status_code=400, detail="Invalid slug format")

    template_id = f"tpl-{secrets.token_hex(8)}"

    with get_db() as conn:
        try:
            conn.execute("""
                INSERT INTO agent_templates
                (template_id, name, slug, description, author_id, author_name,
                 category, tier_required, is_public, license, repository_url,
                 documentation_url, tags, capabilities, requirements)
                VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
            """, (
                template_id, template.name, template.slug, template.description,
                ctx.tenant_id, ctx.user_id or ctx.tenant_id, template.category,
                template.tier_required, 1 if template.is_public else 0, template.license,
                template.repository_url, template.documentation_url,
                json.dumps(template.tags), json.dumps(template.capabilities),
                json.dumps(template.requirements) if template.requirements else None
            ))

            # Initialize stats
            conn.execute("""
                INSERT INTO template_stats (template_id) VALUES (?)
            """, (template_id,))

            conn.commit()
        except sqlite3.IntegrityError as e:
            raise HTTPException(status_code=409, detail=f"Template slug already exists: {e}")

    return {"status": "created", "template_id": template_id}


@router.post("/templates/{template_id}/versions")
async def create_version(
    template_id: str,
    version: TemplateVersionCreate,
    ctx: TenantContext = None
):
    """Publish a new version of a template"""
    if ctx is None:
        ctx = TenantContext()

    # Verify ownership
    with get_db() as conn:
        cursor = conn.execute("""
            SELECT author_id FROM agent_templates WHERE template_id = ?
        """, (template_id,))
        template = cursor.fetchone()

        if not template:
            raise HTTPException(status_code=404, detail="Template not found")
        if template["author_id"] != ctx.tenant_id:
            raise HTTPException(status_code=403, detail="Not template owner")

        version_id = f"ver-{secrets.token_hex(8)}"
        version_number = parse_version(version.version)
        content_json = json.dumps(version.template_content)
        file_hash = hashlib.sha256(content_json.encode()).hexdigest()

        try:
            conn.execute("""
                INSERT INTO template_versions
                (version_id, template_id, version, version_number, release_notes,
                 config_schema, template_content, file_hash, is_stable)
                VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)
            """, (
                version_id, template_id, version.version, version_number,
                version.release_notes,
                json.dumps(version.config_schema) if version.config_schema else None,
                content_json, file_hash, 1 if version.is_stable else 0
            ))

            # Update template timestamp
            conn.execute("""
                UPDATE agent_templates SET updated_at = datetime('now')
                WHERE template_id = ?
            """, (template_id,))

            conn.commit()
        except sqlite3.IntegrityError:
            raise HTTPException(status_code=409, detail="Version already exists")

    return {"status": "created", "version_id": version_id, "version": version.version}


@router.patch("/templates/{template_id}")
async def update_template(
    template_id: str,
    update: TemplateUpdate,
    ctx: TenantContext = None
):
    """Update template metadata"""
    if ctx is None:
        ctx = TenantContext()

    with get_db() as conn:
        # Verify ownership
        cursor = conn.execute("""
            SELECT author_id FROM agent_templates WHERE template_id = ?
        """, (template_id,))
        template = cursor.fetchone()

        if not template:
            raise HTTPException(status_code=404, detail="Template not found")
        if template["author_id"] != ctx.tenant_id:
            raise HTTPException(status_code=403, detail="Not template owner")

        updates = []
        params = []

        if update.name is not None:
            updates.append("name = ?")
            params.append(update.name)
        if update.description is not None:
            updates.append("description = ?")
            params.append(update.description)
        if update.category is not None:
            updates.append("category = ?")
            params.append(update.category)
        if update.is_public is not None:
            updates.append("is_public = ?")
            params.append(1 if update.is_public else 0)
        if update.tags is not None:
            updates.append("tags = ?")
            params.append(json.dumps(update.tags))
        if update.capabilities is not None:
            updates.append("capabilities = ?")
            params.append(json.dumps(update.capabilities))

        if not updates:
            raise HTTPException(status_code=400, detail="No fields to update")

        updates.append("updated_at = datetime('now')")
        params.append(template_id)

        conn.execute(
            f"UPDATE agent_templates SET {', '.join(updates)} WHERE template_id = ?",
            params
        )
        conn.commit()

    return {"status": "updated", "template_id": template_id}


# =============================================================================
# Installation Endpoints
# =============================================================================

@router.post("/install")
async def install_template(
    install: TemplateInstall,
    ctx: TenantContext = None
):
    """Install a template to current project"""
    if ctx is None:
        ctx = TenantContext()

    with get_db() as conn:
        # Get template
        cursor = conn.execute("""
            SELECT template_id, is_public, author_id FROM agent_templates
            WHERE template_id = ?
        """, (install.template_id,))
        template = cursor.fetchone()

        if not template:
            raise HTTPException(status_code=404, detail="Template not found")

        # Check access (public or owner)
        if not template["is_public"] and template["author_id"] != ctx.tenant_id:
            raise HTTPException(status_code=403, detail="Template not accessible")

        # Get version (latest stable if not specified)
        if install.version:
            cursor = conn.execute("""
                SELECT version_id FROM template_versions
                WHERE template_id = ? AND version = ?
            """, (install.template_id, install.version))
        else:
            cursor = conn.execute("""
                SELECT version_id FROM template_versions
                WHERE template_id = ? AND is_stable = 1
                ORDER BY version_number DESC LIMIT 1
            """, (install.template_id,))

        version = cursor.fetchone()
        if not version:
            raise HTTPException(status_code=404, detail="Version not found")

        # Install
        conn.execute("""
            INSERT INTO template_installations
            (template_id, version_id, tenant_id, project_id, config_overrides)
            VALUES (?, ?, ?, ?, ?)
            ON CONFLICT(template_id, tenant_id, project_id) DO UPDATE SET
            version_id = ?, config_overrides = ?, updated_at = datetime('now')
        """, (
            install.template_id, version["version_id"], ctx.tenant_id, ctx.project_id,
            json.dumps(install.config_overrides) if install.config_overrides else None,
            version["version_id"],
            json.dumps(install.config_overrides) if install.config_overrides else None
        ))

        # Update stats
        update_template_stats(conn, install.template_id, "total_installs")
        update_template_stats(conn, install.template_id, "active_installs")

        # Record download
        conn.execute("""
            INSERT INTO template_downloads (template_id, version_id, tenant_id)
            VALUES (?, ?, ?)
        """, (install.template_id, version["version_id"], ctx.tenant_id))

        update_template_stats(conn, install.template_id, "total_downloads")

        conn.commit()

    return {"status": "installed", "template_id": install.template_id}


@router.get("/installed")
async def list_installed(
    ctx: TenantContext = None
):
    """List templates installed in current project"""
    if ctx is None:
        ctx = TenantContext()

    with get_db() as conn:
        cursor = conn.execute("""
            SELECT i.*, t.name, t.description, t.category, v.version
            FROM template_installations i
            JOIN agent_templates t ON i.template_id = t.template_id
            LEFT JOIN template_versions v ON i.version_id = v.version_id
            WHERE i.tenant_id = ? AND i.project_id = ?
            ORDER BY i.installed_at DESC
        """, (ctx.tenant_id, ctx.project_id))
        installed = rows_to_list(cursor.fetchall())

    return {"installed": installed, "count": len(installed)}


@router.delete("/installed/{template_id}")
async def uninstall_template(
    template_id: str,
    ctx: TenantContext = None
):
    """Uninstall a template from current project"""
    if ctx is None:
        ctx = TenantContext()

    with get_db() as conn:
        cursor = conn.execute("""
            DELETE FROM template_installations
            WHERE template_id = ? AND tenant_id = ? AND project_id = ?
        """, (template_id, ctx.tenant_id, ctx.project_id))
        conn.commit()

        if cursor.rowcount == 0:
            raise HTTPException(status_code=404, detail="Installation not found")

        # Update active installs
        conn.execute("""
            UPDATE template_stats
            SET active_installs = active_installs - 1, updated_at = datetime('now')
            WHERE template_id = ? AND active_installs > 0
        """, (template_id,))
        conn.commit()

    return {"status": "uninstalled", "template_id": template_id}


# =============================================================================
# Rating Endpoints
# =============================================================================

@router.post("/templates/{template_id}/rate")
async def rate_template(
    template_id: str,
    rating: TemplateRating,
    ctx: TenantContext = None
):
    """Rate and review a template"""
    if ctx is None:
        ctx = TenantContext()

    with get_db() as conn:
        # Check if template exists
        cursor = conn.execute("""
            SELECT 1 FROM agent_templates WHERE template_id = ?
        """, (template_id,))
        if not cursor.fetchone():
            raise HTTPException(status_code=404, detail="Template not found")

        # Check if user has installed (verified reviewer)
        cursor = conn.execute("""
            SELECT 1 FROM template_installations
            WHERE template_id = ? AND tenant_id = ?
        """, (template_id, ctx.tenant_id))
        is_verified = 1 if cursor.fetchone() else 0

        conn.execute("""
            INSERT INTO template_ratings
            (template_id, tenant_id, user_id, rating, review_title, review_text, is_verified_user)
            VALUES (?, ?, ?, ?, ?, ?, ?)
            ON CONFLICT(template_id, tenant_id) DO UPDATE SET
            rating = ?, review_title = ?, review_text = ?, updated_at = datetime('now')
        """, (
            template_id, ctx.tenant_id, ctx.user_id, rating.rating,
            rating.review_title, rating.review_text, is_verified,
            rating.rating, rating.review_title, rating.review_text
        ))

        # Recalculate average
        calculate_avg_rating(conn, template_id)
        conn.commit()

    return {"status": "rated", "template_id": template_id, "rating": rating.rating}


@router.get("/templates/{template_id}/ratings")
async def get_ratings(
    template_id: str,
    limit: int = Query(20, le=100),
    offset: int = Query(0, ge=0)
):
    """Get ratings for a template"""
    with get_db() as conn:
        cursor = conn.execute("""
            SELECT rating, review_title, review_text, is_verified_user, created_at
            FROM template_ratings
            WHERE template_id = ?
            ORDER BY created_at DESC
            LIMIT ? OFFSET ?
        """, (template_id, limit, offset))
        ratings = rows_to_list(cursor.fetchall())

        # Get summary
        cursor = conn.execute("""
            SELECT avg_rating, rating_count FROM template_stats
            WHERE template_id = ?
        """, (template_id,))
        stats = cursor.fetchone()

    return {
        "ratings": ratings,
        "count": len(ratings),
        "avg_rating": stats["avg_rating"] if stats else 0,
        "total_ratings": stats["rating_count"] if stats else 0
    }


# =============================================================================
# My Templates (Author View)
# =============================================================================

@router.get("/my-templates")
async def list_my_templates(
    ctx: TenantContext = None
):
    """List templates created by current tenant"""
    if ctx is None:
        ctx = TenantContext()

    with get_db() as conn:
        cursor = conn.execute("""
            SELECT t.*, ts.total_downloads, ts.avg_rating, ts.rating_count,
                   ts.active_installs
            FROM agent_templates t
            LEFT JOIN template_stats ts ON t.template_id = ts.template_id
            WHERE t.author_id = ?
            ORDER BY t.updated_at DESC
        """, (ctx.tenant_id,))
        templates = rows_to_list(cursor.fetchall())

        for t in templates:
            t["tags"] = json.loads(t["tags"]) if t.get("tags") else []

    return {"templates": templates, "count": len(templates)}