const { formatMessage } = require('./formatters')

/**
 * Normalize GitHub webhook payload to common format
 * @param {Object} payload - GitHub webhook payload
 * @returns {Object} - Normalized webhook data
 */
const normalizeGithubPayload = (payload) => ({
    repository: {
        full_name: payload.repository.full_name,
        html_url: payload.repository.html_url
    },
    ref: payload.ref,
    commits: payload.commits.map(commit => ({
        id: commit.id,
        message: commit.message,
        stats: {
            additions: commit.stats?.additions || 0,
            deletions: commit.stats?.deletions || 0
        }
    }))
})

/**
 * Handle GitHub webhook
 * @param {Object} payload - Webhook payload
 * @param {Set} reportedCommits - Set of reported commit hashes
 * @param {Map} commitTimestamps - Map of commit timestamps
 * @returns {string|null} - Formatted message or null if no new commits
 */
const handleGithub = (payload, reportedCommits, commitTimestamps) => {
    const data = normalizeGithubPayload(payload)
    
    // Filter new commits
    const newCommits = data.commits.filter(commit => {
        if (reportedCommits.has(commit.id)) return false
        reportedCommits.add(commit.id)
        commitTimestamps.set(commit.id, Date.now())
        return true
    })

    if (newCommits.length === 0) return null

    return formatMessage(data, newCommits)
}

module.exports = { handleGithub }