import { DEBUG, API_URL } from './config.js'

export async function fetchSuggestion(prefix, suffix, signal, apiUrl = API_URL) {
    if (DEBUG) console.log('[Debug] fetchSuggestion called with prefix length:', prefix.length, 'suffix length:', suffix.length)
    try {
        const res = await fetch(apiUrl, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({ prefix, suffix, languageId: 'markdown' }),
            signal
        })

        if (DEBUG) console.log('[Debug] fetchSuggestion response status:', res.status)
        if (!res.ok) {
            const errorText = await res.text()
            throw new Error(`HTTP ${res.status}: ${errorText}`)
        }

        const reader = res.body?.getReader()
        if (!reader) {
            if (DEBUG) console.log('[Debug] No reader available')
            throw new Error('No reader available')
        }

        let text = ''
        let buffer = ''
        while (true) {
            const { done, value } = await reader.read()
            if (done) break
            buffer += new TextDecoder().decode(value)
            
            const lines = buffer.split('\n')
            buffer = lines.pop() || ''
            
            for (const line of lines) {
                if (!line.startsWith('data: ')) continue
                const jsonStr = line.slice(6).trim()
                if (!jsonStr) continue
                try {
                    const data = JSON.parse(jsonStr)
                    if (data.content) {
                        text += data.content
                        if (DEBUG) console.log('[Debug] Added content:', data.content)
                    }
                    if (data.done || data.error) break
                } catch (e) {
                    if (DEBUG) console.warn('[Debug] JSON parse error for:', jsonStr.substring(0, 50))
                }
            }
        }
        
        if (DEBUG) console.log('[Debug] Final suggestion text:', text.substring(0, 100))
        return text
    } catch (e) {
        if (e.name === 'AbortError') {
            if (DEBUG) console.log('[Debug] Request aborted')
        } else {
            if (DEBUG) console.error('[Debug] fetchSuggestion error:', e)
        }
        throw e
    }
}