//! Text generation pipeline implementation
//!
//! This module provides functionality for generating text completions
//! and continuations.

use super::TextGenerationResult;
use crate::error::Result;

/// Text generation pipeline
#[derive(Debug)]
pub struct TextGenerationPipeline {
    /// Maximum length for generation
    max_length: usize,
    /// Number of generations to return
    num_return_sequences: usize,
}

impl Default for TextGenerationPipeline {
    fn default() -> Self {
        Self::new()
    }
}

impl TextGenerationPipeline {
    /// Create new text generation pipeline
    pub fn new() -> Self {
        Self {
            max_length: 50,
            num_return_sequences: 1,
        }
    }

    /// Generate text continuation
    pub fn generate(&self, prompt: &str) -> Result<Vec<TextGenerationResult>> {
        let mut results = Vec::new();

        for i in 0..self.num_return_sequences {
            let continuation = self.generate_continuation(prompt, i);
            let generated_text = format!("{}{}", prompt, continuation);

            results.push(TextGenerationResult {
                generated_text,
                score: Some(0.8 - (i as f64 * 0.1)),
            });
        }

        Ok(results)
    }

    fn generate_continuation(&self, prompt: &str, _sequence_id: usize) -> String {
        // Simple rule-based text generation
        let words = prompt.split_whitespace().collect::<Vec<_>>();
        let last_word = words.last().unwrap_or(&"");

        let continuations = [
            " and this is a continuation.",
            " which leads to interesting possibilities.",
            " that demonstrates the capabilities.",
            " showing how the system works.",
            " providing a complete example.",
        ];

        let continuation_idx = last_word.len() % continuations.len();
        continuations[continuation_idx].to_string()
    }

    /// Set generation parameters
    pub fn set_max_length(&mut self, max_length: usize) {
        self.max_length = max_length;
    }

    /// Set the number of sequences to return
    pub fn set_num_return_sequences(&mut self, num_sequences: usize) {
        self.num_return_sequences = num_sequences;
    }
}
