Initial backend

Backend/Dockerfile

+FROM ghcr.io/osgeo/gdal:alpine-normal-3.8.5
+
+
+WORKDIR /srv/app
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+
+COPY app ./app
+ENV PORT=8000
+CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "8000"]
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Backend/README.md

+# Quick start
+
+
+## Local (Python)
+python -m venv .venv && source .venv/bin/activate
+pip install -r requirements.txt
+cp .env.example .env # fill credentials
+uvicorn app.main:app --reload
+
+
+Open http://localhost:8000/docs
+
+
+### Example: Search CDSE Sentinel‑2 L2A
+curl -X POST http://localhost:8000/search \
+-H 'content-type: application/json' \
+-d '{
+"provider":"cdse",
+"bbox":{"minx":20.78,"miny":50.16,"maxx":20.90,"maxy":50.24},
+"datetime":"2020-01-01/2020-12-31",
+"max_cloud":20,
+"limit":10
+}'
+
+
+### Example: Build a time series for slider (CDSE)
+curl -X POST http://localhost:8000/timeseries \
+-H 'content-type: application/json' \
+-d '{
+"provider":"cdse",
+"bbox":{"minx":20.78,"miny":50.16,"maxx":20.90,"maxy":50.24},
+"datetime":"2019-01-01/2024-12-31",
+"max_cloud":15,
+"limit":30
+}'
+
+
+### Example: View COG tiles (True Color) using TiTiler
+# Replace <COG_URL> with a Sentinel‑2 L2A COG (e.g., from AWS sentinel-cogs)
+open "http://localhost:8000/tiles/cog/tilejson.json?url=<COG_URL>&assets=B04,B03,B02"
+
+
+## Docker
+docker build -t imagery-api .
+docker run -p 8000:8000 --env-file .env imagery-api
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Backend/app/connectors/copernicus_stac.py

+import httpx
+from typing import Optional, List, Dict, Any
+from app.settings import settings
+from app.schemas import ImageryItem, ItemAsset
+from app.util import build_copernicus_browser_link, build_earth_explorer_link
+
+# Default collections for CDSE
+DEFAULT_COLLECTIONS = ["sentinel-2-l2a"]
+
+async def search_cdse(
+    *,
+    bbox: Optional[List[float]] = None,
+    geometry: Optional[Dict[str, Any]] = None,
+    datetime: str,
+    max_cloud: Optional[float] = 30,
+    collections: Optional[List[str]] = None,
+    limit: int = 50,
+    sort: str = "desc",
+) -> Dict[str, Any]:
+    url = f"{settings.cdse_stac_endpoint}/search"
+    cols = collections or DEFAULT_COLLECTIONS
+
+    query: Dict[str, Any] = {
+        "collections": cols,
+        "datetime": datetime,
+        "limit": limit,
+        "sortby": [{"field": "properties.datetime", "direction": sort}],
+    }
+
+    if bbox:
+        query["bbox"] = bbox
+    if geometry:
+        query["intersects"] = geometry
+    if max_cloud is not None:
+        # STAC eo:cloud_cover (<= max_cloud)
+        query.setdefault("query", {})["eo:cloud_cover"] = {"lte": max_cloud}
+
+    async with httpx.AsyncClient(timeout=60) as client:
+        r = await client.post(url, json=query)
+        r.raise_for_status()
+        return r.json()
+
+
+def normalize_cdse_item(feat: Dict[str, Any]) -> ImageryItem:
+    props = feat.get("properties", {})
+    assets = {
+        k: ItemAsset(key=k, href=v.get("href"), roles=v.get("roles"), type=v.get("type"))
+        for k, v in feat.get("assets", {}).items()
+    }
+    # Thumbnail / overview keys vary; try common ones
+    preview = None
+    for key in ("thumbnail", "rendered_preview", "overview", "preview"):
+        if key in feat.get("assets", {}):
+            preview = feat["assets"][key]["href"]
+            break
+
+    geom = feat.get("geometry") or {}
+    lon = geom.get("coordinates", [[[0, 0]]])[0][0][0]
+    lat = geom.get("coordinates", [[[0, 0]]])[0][0][1]
+
+    return ImageryItem(
+        id=feat.get("id"),
+        provider="cdse",
+        collection=feat.get("collection", "sentinel-2-l2a"),
+        datetime=props.get("datetime"),
+        geometry=geom,
+        bbox=feat.get("bbox", []),
+        assets=assets,
+        preview=preview,
+        linkouts={
+            "copernicus_browser": build_copernicus_browser_link(lat, lon, props.get("datetime", "")),
+            "earth_explorer": build_earth_explorer_link(),
+        },
+    )
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Backend/app/connectors/usgs_m2m.py

+import httpx
+from typing import Optional, List, Dict, Any
+from app.settings import settings
+from app.schemas import ImageryItem, ItemAsset
+from app.util import build_earth_explorer_link
+
+# Common Landsat dataset names (search / override as needed)
+DEFAULT_DATASETS = [
+    "LANDSAT_8_C2_L2",
+    "LANDSAT_9_C2_L2",
+]
+
+
+async def _m2m_auth(client: httpx.AsyncClient) -> str:
+    """Authenticate using USGS M2M application token (login-token)."""
+    url = f"{settings.usgs_m2m_base}/api/login-token"
+    payload = {
+        "username": settings.usgs_m2m_username,
+        "token": settings.usgs_m2m_app_token,
+    }
+    r = await client.post(url, json=payload)
+    r.raise_for_status()
+    return r.json()["data"]["apiKey"]
+
+
+async def search_usgs(
+    *,
+    bbox: Optional[List[float]] = None,
+    geometry: Optional[Dict[str, Any]] = None,
+    datetime: str,
+    datasets: Optional[List[str]] = None,
+    max_results: int = 50,
+) -> List[Dict[str, Any]]:
+    datasets = datasets or DEFAULT_DATASETS
+    async with httpx.AsyncClient(timeout=60) as client:
+        api_key = await _m2m_auth(client)
+        headers = {"X-Auth-Token": api_key}
+
+        results: List[Dict[str, Any]] = []
+        for ds in datasets:
+            url = f"{settings.usgs_m2m_base}/api/scene-search"
+            payload: Dict[str, Any] = {
+                "datasetName": ds,
+                "maxResults": max_results,
+                "temporalFilter": {"start": datetime.split("/")[0], "end": datetime.split("/")[1]},
+            }
+            if bbox:
+                payload["spatialFilter"] = {"filterType": "mbr", "lowerLeft": {"longitude": bbox[0], "latitude": bbox[1]}, "upperRight": {"longitude": bbox[2], "latitude": bbox[3]}}
+            if geometry:
+                payload["spatialFilter"] = {"filterType": "geojson", "geoJson": geometry}
+
+            r = await client.post(url, json=payload, headers=headers)
+            r.raise_for_status()
+            data = r.json()
+            if data.get("data", {}).get("results"):
+                results.extend([dict(x, dataset=ds) for x in data["data"]["results"]])
+        return results
+
+
+def normalize_usgs_item(scene: Dict[str, Any]) -> ImageryItem:
+    # USGS response differs; normalize minimally for the viewer
+    entity_id = scene.get("entityId") or scene.get("entity_id")
+    acq_date = scene.get("acquisitionDate") or scene.get("temporalCoverage", {}).get("startDate")
+    geom = scene.get("spatialBounds", {}).get("coordinates")
+    bbox = scene.get("spatialBounds", {}).get("bbox") or []
+
+    assets: Dict[str, ItemAsset] = {}
+    quicklook = scene.get("browseUrl") or scene.get("thumbnailUrl")
+    if quicklook:
+        assets["thumbnail"] = ItemAsset(key="thumbnail", href=quicklook, roles=["thumbnail"], type="image/jpeg")
+
+    return ImageryItem(
+        id=entity_id,
+        provider="usgs",
+        collection=scene.get("dataset"),
+        datetime=acq_date,
+        geometry={"type": "Polygon", "coordinates": geom} if geom else {"type": "Polygon", "coordinates": []},
+        bbox=bbox,
+        assets=assets,
+        preview=quicklook,
+        linkouts={
+            "earth_explorer": build_earth_explorer_link(),
+        },
+    )
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Backend/app/deps.py

+from fastapi import Depends
+from app.settings import settings
+
+
+def get_settings():
+    return settings
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Backend/app/main.py

+from fastapi import FastAPI
+from fastapi.middleware.cors import CORSMiddleware
+from app.settings import settings
+from app.routers import search, timeseries, tiles
+
+
+app = FastAPI(title="Imagery Time-Slider API", version="0.1.0")
+
+
+app.add_middleware(
+CORSMiddleware,
+allow_origins=settings.allowed_origins,
+allow_credentials=True,
+allow_methods=["*"],
+allow_headers=["*"],
+)
+
+
+@app.get("/health")
+async def health():
+    return {"ok": True}
+
+
+app.include_router(search.router)
+app.include_router(timeseries.router)
+app.include_router(tiles.router)
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