Create app.py

app.py

@@ -0,0 +1,176 @@
+from fastapi import FastAPI, HTTPException, Body
+from fastapi.middleware.cors import CORSMiddleware
+
+
+from pydantic import BaseModel, Field
+from datetime import datetime, timezone
+from typing import Literal
+import pytz
+from dateutil import parser as dateutil_parser
+
+app = FastAPI(
+    title="Secure Time Utilities API",
+    version="1.0.0",
+    description="Provides secure UTC/local time retrieval, formatting, timezone conversion, and comparison.",
+)
+
+
+origins = ["*"]
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=origins,
+    allow_credentials=True,
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+
+# -------------------------------
+# Pydantic models
+# -------------------------------
+
+
+class FormatTimeInput(BaseModel):
+    format: str = Field(
+        "%Y-%m-%d %H:%M:%S", description="Python strftime format string"
+    )
+    timezone: str = Field(
+        "UTC", description="IANA timezone name (e.g., UTC, America/New_York)"
+    )
+
+
+class ConvertTimeInput(BaseModel):
+    timestamp: str = Field(
+        ..., description="ISO 8601 formatted time string (e.g., 2024-01-01T12:00:00Z)"
+    )
+    from_tz: str = Field(
+        ..., description="Original IANA time zone of input (e.g. UTC or Europe/Berlin)"
+    )
+    to_tz: str = Field(..., description="Target IANA time zone to convert to")
+
+
+class ElapsedTimeInput(BaseModel):
+    start: str = Field(..., description="Start timestamp in ISO 8601 format")
+    end: str = Field(..., description="End timestamp in ISO 8601 format")
+    units: Literal["seconds", "minutes", "hours", "days"] = Field(
+        "seconds", description="Unit for elapsed time"
+    )
+
+
+class ParseTimestampInput(BaseModel):
+    timestamp: str = Field(
+        ..., description="Flexible input timestamp string (e.g., 2024-06-01 12:00 PM)"
+    )
+    timezone: str = Field(
+        "UTC", description="Assumed timezone if none is specified in input"
+    )
+
+
+# -------------------------------
+# Routes
+# -------------------------------
+
+
+@app.get("/get_current_utc_time", summary="Current UTC time")
+def get_current_utc():
+    """
+    Returns the current time in UTC in ISO format.
+    """
+    return {"utc": datetime.utcnow().replace(tzinfo=timezone.utc).isoformat()}
+
+
+@app.get("/get_current_local_time", summary="Current Local Time")
+def get_current_local():
+    """
+    Returns the current time in local timezone in ISO format.
+    """
+    return {"local_time": datetime.now().isoformat()}
+
+
+@app.post("/format_time", summary="Format current time")
+def format_current_time(data: FormatTimeInput):
+    """
+    Return the current time formatted for a specific timezone and format.
+    """
+    try:
+        tz = pytz.timezone(data.timezone)
+    except Exception:
+        raise HTTPException(
+            status_code=400, detail=f"Invalid timezone: {data.timezone}"
+        )
+    now = datetime.now(tz)
+    try:
+        return {"formatted_time": now.strftime(data.format)}
+    except Exception as e:
+        raise HTTPException(status_code=400, detail=f"Invalid format string: {e}")
+
+
+@app.post("/convert_time", summary="Convert between timezones")
+def convert_time(data: ConvertTimeInput):
+    """
+    Convert a timestamp from one timezone to another.
+    """
+    try:
+        from_zone = pytz.timezone(data.from_tz)
+        to_zone = pytz.timezone(data.to_tz)
+    except Exception as e:
+        raise HTTPException(status_code=400, detail=f"Invalid timezone: {e}")
+
+    try:
+        dt = dateutil_parser.parse(data.timestamp)
+        if dt.tzinfo is None:
+            dt = from_zone.localize(dt)
+        else:
+            dt = dt.astimezone(from_zone)
+        converted = dt.astimezone(to_zone)
+        return {"converted_time": converted.isoformat()}
+    except Exception as e:
+        raise HTTPException(status_code=400, detail=f"Invalid timestamp: {e}")
+
+
+@app.post("/elapsed_time", summary="Time elapsed between timestamps")
+def elapsed_time(data: ElapsedTimeInput):
+    """
+    Calculate the difference between two timestamps in chosen units.
+    """
+    try:
+        start_dt = dateutil_parser.parse(data.start)
+        end_dt = dateutil_parser.parse(data.end)
+        delta = end_dt - start_dt
+    except Exception as e:
+        raise HTTPException(status_code=400, detail=f"Invalid timestamps: {e}")
+
+    seconds = delta.total_seconds()
+    result = {
+        "seconds": seconds,
+        "minutes": seconds / 60,
+        "hours": seconds / 3600,
+        "days": seconds / 86400,
+    }
+
+    return {"elapsed": result[data.units], "unit": data.units}
+
+
+@app.post("/parse_timestamp", summary="Parse and normalize timestamps")
+def parse_timestamp(data: ParseTimestampInput):
+    """
+    Parse human-friendly input timestamp and return standardized UTC ISO time.
+    """
+    try:
+        tz = pytz.timezone(data.timezone)
+        dt = dateutil_parser.parse(data.timestamp)
+        if dt.tzinfo is None:
+            dt = tz.localize(dt)
+        dt_utc = dt.astimezone(pytz.utc)
+        return {"utc": dt_utc.isoformat()}
+    except Exception as e:
+        raise HTTPException(status_code=400, detail=f"Could not parse: {e}")
+
+
+@app.get("/list_time_zones", summary="All valid time zones")
+def list_time_zones():
+    """
+    Return a list of all valid IANA time zones.
+    """
+    return pytz.all_timezones