Initial backend

Backend/app/routers/search.py

+from fastapi import APIRouter, HTTPException
+from app.schemas import SearchBody, SearchResponse
+from app.connectors.copernicus_stac import search_cdse, normalize_cdse_item
+from app.connectors.usgs_m2m import search_usgs, normalize_usgs_item
+from app.util import bbox_to_list
+
+
+router = APIRouter(prefix="/search", tags=["search"])
+
+
+@router.post("", response_model=SearchResponse)
+async def search(body: SearchBody):
+    bbox_list = None
+    if body.bbox:
+        bbox_list = [body.bbox.minx, body.bbox.miny, body.bbox.maxx, body.bbox.maxy]
+
+    if body.provider == "cdse":
+        raw = await search_cdse(
+            bbox=bbox_list,
+            geometry=body.geometry,
+            datetime=body.datetime,
+            max_cloud=body.max_cloud,
+            collections=body.collections,
+            limit=body.limit,
+            sort=body.sort,
+        )
+        items = [normalize_cdse_item(f) for f in raw.get("features", [])]
+        return SearchResponse(items=items, next=raw.get("links", [{}])[-1].get("href"))
+
+    if body.provider == "usgs":
+        scenes = await search_usgs(
+            bbox=bbox_list,
+            geometry=body.geometry,
+            datetime=body.datetime,
+            datasets=body.collections,
+            max_results=body.limit,
+        )
+        items = [normalize_usgs_item(s) for s in scenes]
+        return SearchResponse(items=items)
+
+    # Optional AWS COG source kept for future expansion
+    raise HTTPException(400, detail="Unsupported provider for search")
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Backend/app/routers/tiles.py

+from fastapi import APIRouter
+from titiler.core.factory import TilerFactory
+
+
+router = APIRouter()
+
+
+# Mount TiTiler COG endpoints at /tiles/cog
+cog = TilerFactory(router_prefix="/tiles/cog")
+router.include_router(cog.router)
+
+
+# Notes:
+# - Use /tiles/cog/tilejson.json?url=<COG_URL>&assets=B04,B03,B02 for RGB
+# - For S2 COGs on AWS, pass the HTTPS URL (RequesterPays OFF for Element84 COGs)
+# - Frontend can consume the returned tilejson.tiles[0] template directly
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Backend/app/routers/timeseries.py

+from fastapi import APIRouter, HTTPException
+from typing import List
+from app.schemas import SearchBody, TimeSeriesResponse, TimeSlice
+from app.routers.search import search as do_search
+
+
+router = APIRouter(prefix="/timeseries", tags=["timeseries"])
+
+
+@router.post("", response_model=TimeSeriesResponse)
+async def timeseries(body: SearchBody):
+    # Reuse /search, then map to time slices; front-end can plug this into a slider
+    res = await do_search(body)
+    slices: List[TimeSlice] = []
+    for it in sorted(res.items, key=lambda x: x.datetime):
+        # If you mount /tiles (TiTiler), front-end can request dynamic RGB tiles per item/asset
+        slices.append(TimeSlice(
+            iso_date=it.datetime,
+            label=it.datetime.split("T")[0] if it.datetime else "",
+            item_id=it.id,
+            provider=it.provider,
+            # tile_template can be filled after you implement your own tiling logic
+            tile_template=None,
+            tilejson=None,
+        ))
+    return TimeSeriesResponse(slices=slices)
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Backend/app/schemas.py

+from pydantic import BaseModel, Field
+from typing import Literal, Optional, List, Dict, Any
+
+
+Provider = Literal["cdse", "usgs", "aws_s2_cog"]
+
+
+class BBox(BaseModel):
+    # WebMercator / WGS84 lon/lat
+    minx: float
+    miny: float
+    maxx: float
+    maxy: float
+
+
+class SearchBody(BaseModel):
+    provider: Provider
+    bbox: Optional[BBox] = None
+    geometry: Optional[Dict[str, Any]] = None  # GeoJSON
+    datetime: str = Field(..., description="STAC datetime interval e.g. 2020-01-01/2020-12-31")
+    max_cloud: Optional[float] = 30
+    collections: Optional[List[str]] = None  # override defaults per provider
+    limit: int = 50
+    sort: Literal["asc", "desc"] = "desc"
+
+
+class ItemAsset(BaseModel):
+    key: str
+    href: str
+    roles: Optional[List[str]] = None
+    type: Optional[str] = None
+
+
+class ImageryItem(BaseModel):
+    id: str
+    provider: Provider
+    collection: str
+    datetime: str
+    geometry: Dict[str, Any]
+    bbox: List[float]
+    assets: Dict[str, ItemAsset]
+    preview: Optional[str] = None  # thumbnail URL if available
+    linkouts: Optional[Dict[str, str]] = None  # Copernicus Browser / EarthExplorer links
+
+
+class SearchResponse(BaseModel):
+    items: List[ImageryItem]
+    next: Optional[str] = None
+
+
+class TimeSlice(BaseModel):
+    iso_date: str
+    label: str
+    item_id: str
+    provider: Provider
+    tilejson: Optional[Dict[str, Any]] = None
+    tile_template: Optional[str] = None
+
+
+class TimeSeriesResponse(BaseModel):
+    slices: List[TimeSlice]
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Backend/app/settings.py

+from pydantic_settings import BaseSettings
+from typing import List
+
+
+class Settings(BaseSettings):
+    cdse_stac_endpoint: str = "https://stac.dataspace.copernicus.eu/v1"
+    cdse_oauth_token_url: str | None = None
+    cdse_client_id: str | None = None
+    cdse_client_secret: str | None = None
+
+    usgs_m2m_base: str = "https://m2m.cr.usgs.gov"
+    usgs_m2m_username: str | None = None
+    usgs_m2m_app_token: str | None = None
+
+    sentinel_hub_instance_id: str | None = None
+
+    tile_cache_dir: str = "./cache"
+    allowed_origins: List[str] = ["*"]
+
+    class Config:
+        env_file = ".env"
+
+
+settings = Settings()
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Backend/app/util.py

+from typing import Dict, Any, List, Optional
+
+
+def bbox_to_list(bbox) -> List[float]:
+    return [bbox.minx, bbox.miny, bbox.maxx, bbox.maxy]
+
+
+def stac_datetime(start: str, end: str) -> str:
+    return f"{start}/{end}"
+
+
+def iso_to_label(iso: str) -> str:
+    # 2020-05-17T10:11:12Z -> 2020‑05‑17
+    return iso.split("T")[0]
+
+
+def build_copernicus_browser_link(lat: float, lon: float, date_iso: str, cloud: int = 30) -> str:
+    base = "https://browser.dataspace.copernicus.eu/"
+    return (f"{base}?zoom=13&lat={lat:.6f}&lng={lon:.6f}"
+            f"&themeId=DEFAULT-THEME&datasetId=S2_L2A_CDAS&cloudCoverage={cloud}"
+            f"&dateMode=SINGLE&toTime={date_iso}")
+
+
+def build_earth_explorer_link() -> str:
+    # EE does not accept bbox in URL; provide homepage link
+    return "https://earthexplorer.usgs.gov/"
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Backend/env.example

+# === Copernicus Data Space Ecosystem ===
+CDSE_STAC_ENDPOINT=https://stac.dataspace.copernicus.eu/v1
+# OAuth client (needed for S3/download/process later; STAC search can be public)
+CDSE_OAUTH_TOKEN_URL=https://identity.dataspace.copernicus.eu/auth/realms/CDSE/protocol/openid-connect/token
+CDSE_CLIENT_ID=
+CDSE_CLIENT_SECRET=
+
+
+# === USGS M2M ===
+# As of 2025, use Application Token with the login-token endpoint
+USGS_M2M_USERNAME=
+USGS_M2M_APP_TOKEN=
+USGS_M2M_BASE=https://m2m.cr.usgs.gov
+
+
+# === Optional: Sentinel Hub OGC (WMS/WMTS) passthrough ===
+SENTINEL_HUB_INSTANCE_ID=
+
+
+# === Tile cache & general ===
+TILE_CACHE_DIR=./cache
+ALLOWED_ORIGINS=*
+LOG_LEVEL=info
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Backend/requirements.txt

+fastapi==0.115.0
+uvicorn[standard]==0.30.6
+httpx==0.27.2
+pydantic==2.9.2
+pydantic-settings==2.5.2
+python-dotenv==1.0.1
+# Optional (for /tiles with COGs)
+titiler.core==0.16.2
+rio-tiler==6.7.0
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