// Name: Customer.io Top Clicked Links
// Description: Get the top clicked links for my AI Dev Essentials newsletter

// You can find the newsletter here:
// https://egghead.io/newsletters/ai-dev-essentials

import "@johnlindquist/kit"

// Prompt (or load) your Customer.io App (not tracking) API key
const API_KEY = await env('CIO_API_KEY')

// Customer.io App API base (US region). Remove the extra /api segment
const API_BASE = 'https://api.customer.io/v1'

/**
 * Shape of each newsletter returned by the `/newsletters` endpoint.
 */
interface NewsletterSummary {
    id: number
    name: string
    // Allow unknown extra properties without failing type-checking
    [key: string]: unknown
}

let newsletters: NewsletterSummary[] = []
try {
    // We want one-off newsletters, not API-triggered broadcasts, so we hit /newsletters
    const listResp = await get(`${API_BASE}/newsletters`, {
        headers: { Authorization: `Bearer ${API_KEY}` },
    })

    // The API might place the array under different keys, so check each option in order
    if (Array.isArray(listResp.data.newsletters)) {
        newsletters = listResp.data.newsletters
    } else if (Array.isArray(listResp.data.broadcasts)) {
        newsletters = listResp.data.broadcasts
    } else if (Array.isArray(listResp.data.items)) {
        newsletters = listResp.data.items
    } else if (Array.isArray(listResp.data.campaigns)) {
        newsletters = listResp.data.campaigns
    } else if (Array.isArray(listResp.data)) {
        newsletters = listResp.data
    }

    if (newsletters.length === 0) {
        await div(md('No newsletters found for this workspace.'))
        exit(0)
    }
} catch (err) {
    console.error('Error fetching newsletter list:', err)
    await div(md('❌ Failed to fetch newsletters. Check your API key, region, or network.'))
    exit(1)
}

// ---------- 2) Let the user choose a newsletter ----------

const choiceItems: {
    name: string
    description: string
    value: NewsletterSummary
}[] = []

for (const nl of newsletters) {
    const displayName = nl.name ? String(nl.name) : `Newsletter ${nl.id}`
    if (nl.name.includes('AI Dev Essentials')) {
        choiceItems.push({ name: displayName, description: `ID: ${nl.id}`, value: nl })
    }
}

//sort choiceItems by id descending
choiceItems.sort((a, b) => {
    return b.value.id - a.value.id
})

const selectedNewsletter = await arg(
    {
        placeholder: 'Select a newsletter to inspect',
        hint: 'Customer.io newsletters',
        strict: true,
    },
    choiceItems
)

const newsletterId = selectedNewsletter.id

// ---------- 3) Fetch link-click metrics for the chosen newsletter ----------

const params = {
    period: 'days',
    steps: 30, // last 30 days
    unique: 'false', // total clicks (not unique)
}

try {
    const metricsResp = await get(`${API_BASE}/newsletters/${newsletterId}/metrics/links`, {
        headers: { Authorization: `Bearer ${API_KEY}` },
        params: params,
    })

    const linkMetrics = metricsResp.data.links ?? []
    if (!Array.isArray(linkMetrics) || linkMetrics.length === 0) {
        await div(md(`No link click data available for **${selectedNewsletter.name}**.`))
        exit(0)
    }

    // Uncomment the line below to inspect the raw API response in an editor window
    // await editor(JSON.stringify(linkMetrics, null, 2))

    // -------- 4) Transform raw metrics into a friendlier structure --------

    interface LinkClickSummary {
        url: string
        clicks: number
    }

    const summaries: LinkClickSummary[] = []
    for (const metricItem of linkMetrics) {
        // Extract the URL
        let url = 'undefined'
        if (metricItem.link && metricItem.link.href) {
            url = String(metricItem.link.href)
        } else if (metricItem.url) {
            url = String(metricItem.url)
        } else if (metricItem.href) {
            url = String(metricItem.href)
        }

        // Sum daily clicks
        let totalClicks = 0
        const dailyArray: number[] = metricItem.metric?.series?.clicked ?? []
        if (Array.isArray(dailyArray)) {
            for (const n of dailyArray) {
                totalClicks += n
            }
        }

        summaries.push({ url, clicks: totalClicks })
    }

    // Sort links by total clicks descending
    summaries.sort((a, b) => b.clicks - a.clicks)

    // Prepare a Markdown table of top links (limit to top 10)
    const topLinks = summaries.slice(0, 10)

    const tableLines: string[] = ['| Rank | URL | Clicks |', '|-----:|-----|-------:|']
    for (let i = 0; i < topLinks.length; i++) {
        const l = topLinks[i]
        tableLines.push(`| ${i + 1} | ${l.url} | ${l.clicks} |`)
    }

    await div(md(`## Top Clicked Links for **${selectedNewsletter.name}**\n\n${tableLines.join('\n')}`))
} catch (err) {
    console.error('Error fetching link metrics:', err)
    await div(md('❌ Failed to fetch link metrics.'))
    exit(1)
}