"""
Cost Tracker - Token cost estimation for API calls.

This module provides cost estimation for different LLM providers based on per-token pricing.
 It is used to display estimated costs in the MMA Dashboard.

Pricing Data (per 1M tokens):
 - gemini-2.5-flash-lite: $0.075 input / $0.30 output
 - gemini-3-flash-preview: $0.15 input / $0.60 output
 - gemini-3.1-pro-preview: $3.50 input / $10.50 output
 - claude-*-sonnet: $3.0 input / $15.0 output
 - claude-*-opus: $15.0 input / $75.0 output
 - deepseek-v3: $0.27 input / $1.10 output

Usage:
 from src.cost_tracker import estimate_cost

 total = estimate_cost("gemini-2.5-flash-lite", 50000, 10000)
 # Returns: 0.007 (approx)

Accuracy:
 - Pricing data may be outdated
 - Uses regex matching for model identification
 - Returns 0.0 for unknown models

Integration:
 - Used by gui_2.py for MMA dashboard cost display
 - Called after each API call

See Also:
 - src/ai_client.py for token tracking
 - docs/guide_mma.md for MMA dashboard documentation
"""
import re

# Pricing per 1M tokens in USD
MODEL_PRICING = [
    (r"gemini-2\.5-flash-lite", {"input_per_mtok": 0.075, "output_per_mtok": 0.30}),
    (r"gemini-2\.5-flash", {"input_per_mtok": 0.15, "output_per_mtok": 0.60}),
    (r"gemini-3-flash-preview", {"input_per_mtok": 0.15, "output_per_mtok": 0.60}),
    (r"gemini-3\.1-pro-preview", {"input_per_mtok": 3.50, "output_per_mtok": 10.50}),
    (r"claude-.*-sonnet", {"input_per_mtok": 3.0, "output_per_mtok": 15.0}),
    (r"claude-.*-opus", {"input_per_mtok": 15.0, "output_per_mtok": 75.0}),
    (r"deepseek-v3", {"input_per_mtok": 0.27, "output_per_mtok": 1.10}),
]

def estimate_cost(model: str, input_tokens: int, output_tokens: int) -> float:
    """
    Estimate the cost of a model call based on input and output tokens.
    Returns the total cost in USD.
    """
    if not model:
        return 0.0
        
    for pattern, rates in MODEL_PRICING:
        if re.search(pattern, model, re.IGNORECASE):
            input_cost = (input_tokens / 1_000_000) * rates["input_per_mtok"]
            output_cost = (output_tokens / 1_000_000) * rates["output_per_mtok"]
            return input_cost + output_cost
            
    return 0.0