import Anthropic from "@anthropic-ai/sdk"
import * as actualApi from "@actual-app/api"
import * as p from "@clack/prompts"
import { loadConfig } from "../config"
import { initActual } from "../actual"
import type { Config } from "../config"

const api = actualApi as any

export async function aiCommand(args: string[]) {
    const config = loadConfig()

    if (!config.anthropicApiKey) {
        console.error("Error: No Anthropic API key configured. Run `sb1-actual init` to add one.")
        process.exit(1)
    }

    const subcommand = args[0]
    if (!subcommand) {
        printHelp()
        process.exit(1)
    }

    const client = new Anthropic({ apiKey: config.anthropicApiKey })

    p.intro(`sb1-actual ai ${subcommand}`)

    await initActual(config.actual)

    switch (subcommand) {
        case "consolidate-payees":
            await consolidatePayees(client)
            break
        case "summarize":
            await summarize(client, config, args.slice(1))
            break
        case "insights":
            await insights(client, config, args.slice(1))
            break
        case "add-notes":
            await addNotes(client, config, args.slice(1))
            break
        case "query":
            await query(client, config, args.slice(1))
            break
        default:
            console.error(`Unknown subcommand: ${subcommand}`)
            printHelp()
            process.exit(1)
    }
}

function printHelp() {
    console.log("Usage: sb1-actual ai <subcommand> [options]")
    console.log("")
    console.log("Subcommands:")
    console.log("  query [--since=YYYY-MM-DD] [question]  Ask a free-form question about your data")
    console.log("  consolidate-payees                     Identify and merge duplicate/similar payees")
    console.log("  summarize [--since=YYYY-MM-DD]         Summarize spending by category and payee")
    console.log("  insights  [--since=YYYY-MM-DD]         Get AI insights into spending patterns")
    console.log("  add-notes [--since=YYYY-MM-DD]         Add descriptive notes to transactions")
    console.log("  add-notes --dry-run                    Preview notes without applying them")
}

function extractJson(text: string): any {
    // Strip markdown code fences: ```json ... ``` or ``` ... ```
    const fenced = text.match(/```(?:json)?\s*([\s\S]*?)```/)
    const raw = fenced ? fenced[1] : text
    // Find the first [...] or {...} block
    const match = raw.match(/(\[[\s\S]*\]|\{[\s\S]*\})/)
    if (!match) throw new Error("No JSON found in response")
    return JSON.parse(match[1])
}

function defaultSince(): string {
    const d = new Date()
    d.setDate(d.getDate() - 90)
    return d.toISOString().split("T")[0]
}

async function loadTransactions(config: Config, since?: string) {
    const startDate = since ?? defaultSince()
    const allTxns: any[] = []
    for (const mapping of config.mappings) {
        const txns = await api.getTransactions(mapping.actualId, startDate, undefined)
        allTxns.push(...txns)
    }
    return allTxns
}

async function resolveNames(transactions: any[]) {
    const payees: Array<{ id: string; name: string }> = await api.getPayees()
    const categories: Array<{ id: string; name: string }> = await api.getCategories()
    const payeeMap = new Map(payees.map(p => [p.id, p.name]))
    const categoryMap = new Map(categories.map(c => [c.id, c.name]))

    return {
        payees,
        payeeMap,
        categoryMap,
        formatted: transactions
            .filter(t => !t.is_parent)
            .map(t => ({
                id: t.id,
                date: t.date,
                amount: (t.amount / 100).toFixed(2),
                payee: payeeMap.get(t.payee) ?? t.imported_payee ?? "Unknown",
                category: categoryMap.get(t.category) ?? "Uncategorized",
                notes: t.notes ?? "",
            })),
    }
}

// ─── consolidate-payees ────────────────────────────────────────────────────

async function consolidatePayees(client: Anthropic) {
    const spinner = p.spinner()
    spinner.start("Loading payees...")

    const payees: Array<{ id: string; name: string; transfer_acct?: string }> = await api.getPayees()
    const realPayees = payees.filter(p => !p.transfer_acct && p.name?.trim())

    spinner.stop(`Loaded ${realPayees.length} payees`)

    if (realPayees.length === 0) {
        p.outro("No payees found.")
        return
    }

    spinner.start("Analyzing payees with Claude...")

    const payeeList = realPayees.map(p => `${p.id}: ${p.name}`).join("\n")

    const response = await client.messages.create({
        model: "claude-haiku-4-5",
        max_tokens: 4096,
        tools: [{
            name: "submit_merge_groups",
            description: "Submit groups of payees that should be merged together",
            input_schema: {
                type: "object" as const,
                properties: {
                    groups: {
                        type: "array",
                        items: {
                            type: "object",
                            properties: {
                                keepId:   { type: "string", description: "ID of the payee whose name to keep" },
                                keepName: { type: "string", description: "The canonical display name" },
                                mergeIds: { type: "array", items: { type: "string" }, description: "IDs to merge in" },
                            },
                            required: ["keepId", "keepName", "mergeIds"],
                        },
                        description: "Merge groups. Empty array if no duplicates found.",
                    },
                },
                required: ["groups"],
            },
        }],
        tool_choice: { type: "tool", name: "submit_merge_groups" },
        system: "You are a personal finance assistant. Identify payees that represent the same merchant (e.g. 'Rema 1000', 'REMA 1000 OSLO', 'REMA1000'). Only group clear duplicates/variants.",
        messages: [{
            role: "user",
            content: `Payees:\n${payeeList}`,
        }]
    })

    spinner.stop("Analysis complete")

    const toolUse = response.content.find(b => b.type === "tool_use") as any
    const groups: Array<{ keepId: string; keepName: string; mergeIds: string[] }> =
        toolUse?.input?.groups?.filter((g: any) => g.mergeIds?.length > 0) ?? []

    if (groups.length === 0) {
        p.outro("No duplicate or similar payees found.")
        return
    }

    console.log(`\nFound ${groups.length} merge group(s):\n`)
    for (const group of groups) {
        const keep = realPayees.find(p => p.id === group.keepId)
        const merging = group.mergeIds.map(id => realPayees.find(p => p.id === id)?.name ?? id)
        console.log(`  Keep:  "${keep?.name ?? group.keepName}"`)
        console.log(`  Merge: ${merging.map(n => `"${n}"`).join(", ")}`)
        console.log()
    }

    const confirm = await p.confirm({ message: "Apply these merges?" })
    if (p.isCancel(confirm) || !confirm) {
        p.cancel("Cancelled.")
        return
    }

    const applySpinner = p.spinner()
    applySpinner.start("Applying merges...")

    let mergedCount = 0
    for (const group of groups) {
        await api.mergePayees(group.keepId, group.mergeIds)
        mergedCount += group.mergeIds.length
    }

    await actualApi.sync()
    applySpinner.stop(`Merged ${mergedCount} payees into ${groups.length} groups`)
    p.outro("Done!")
}

// ─── summarize ────────────────────────────────────────────────────────────

async function summarize(client: Anthropic, config: Config, args: string[]) {
    const since = args.find(a => a.startsWith("--since="))?.split("=")[1]

    const spinner = p.spinner()
    spinner.start("Loading transactions...")

    const transactions = await loadTransactions(config, since)
    const { formatted } = await resolveNames(transactions)

    spinner.stop(`Loaded ${formatted.length} transactions`)

    if (formatted.length === 0) {
        p.outro("No transactions found.")
        return
    }

    const txnText = formatted
        .map(t => `${t.date} | ${Number(t.amount) >= 0 ? "+" : ""}${t.amount} NOK | ${t.payee} | ${t.category}${t.notes ? ` | ${t.notes}` : ""}`)
        .join("\n")

    console.log("")

    const stream = client.messages.stream({
        model: "claude-haiku-4-5",
        max_tokens: 4096,
        system: "You are a personal finance assistant. Summarize transaction data clearly. Group by category and list top payees with totals. Use NOK currency. Use markdown formatting.",
        messages: [{
            role: "user",
            content: `Summarize my spending${since ? ` since ${since}` : ` (last 90 days)`}.\n\nTransactions:\n${txnText}`
        }]
    })

    for await (const event of stream) {
        if (event.type === "content_block_delta" && event.delta.type === "text_delta") {
            process.stdout.write(event.delta.text)
        }
    }

    console.log("\n")
    p.outro("Done!")
}

// ─── insights ─────────────────────────────────────────────────────────────

async function insights(client: Anthropic, config: Config, args: string[]) {
    const since = args.find(a => a.startsWith("--since="))?.split("=")[1]

    const spinner = p.spinner()
    spinner.start("Loading transactions...")

    const transactions = await loadTransactions(config, since)
    const { formatted } = await resolveNames(transactions)

    spinner.stop(`Loaded ${formatted.length} transactions`)

    if (formatted.length === 0) {
        p.outro("No transactions found.")
        return
    }

    const txnText = formatted
        .map(t => `${t.date} | ${Number(t.amount) >= 0 ? "+" : ""}${t.amount} NOK | ${t.payee} | ${t.category}${t.notes ? ` | ${t.notes}` : ""}`)
        .join("\n")

    console.log("")

    const stream = client.messages.stream({
        model: "claude-haiku-4-5",
        max_tokens: 8192,
        system: "You are a personal finance advisor. Analyze transactions and give actionable insights: spending patterns, trends, anomalies, potential savings, and notable observations. Use NOK currency. Use markdown. Be specific and helpful.",
        messages: [{
            role: "user",
            content: `Analyze my spending${since ? ` since ${since}` : ` (last 90 days)`} and give me insights.\n\nTransactions:\n${txnText}`
        }]
    })

    for await (const event of stream) {
        if (event.type === "content_block_delta" && event.delta.type === "text_delta") {
            process.stdout.write(event.delta.text)
        }
    }

    console.log("\n")
    p.outro("Done!")
}

// ─── add-notes ────────────────────────────────────────────────────────────

async function addNotes(client: Anthropic, config: Config, args: string[]) {
    const since = args.find(a => a.startsWith("--since="))?.split("=")[1]
    const dryRun = args.includes("--dry-run")

    const spinner = p.spinner()
    spinner.start("Loading transactions...")

    const transactions = await loadTransactions(config, since)
    const { payeeMap } = await resolveNames(transactions)

    const withoutNotes = transactions
        .filter(t => !t.is_parent && (!t.notes || !t.notes.trim()))
        .slice(0, 50)

    spinner.stop(`Found ${withoutNotes.length} transactions without notes (processing up to 50)`)

    if (withoutNotes.length === 0) {
        p.outro("All transactions already have notes!")
        return
    }

    const toProcess = withoutNotes.map(t => ({
        id: t.id,
        date: t.date,
        amount: (t.amount / 100).toFixed(2),
        payee: payeeMap.get(t.payee) ?? t.imported_payee ?? "Unknown",
    }))

    spinner.start("Generating notes with Claude...")

    const response = await client.messages.create({
        model: "claude-haiku-4-5",
        max_tokens: 4096,
        system: `You are a personal finance assistant. For each transaction, suggest a brief helpful note (max 60 chars) adding context not obvious from the payee name alone.
If the transaction is already self-explanatory, return null for the note.
Return ONLY a JSON array: [{"id": "...", "note": "..." | null}]`,
        messages: [{
            role: "user",
            content: `Add helpful notes to these transactions:\n${JSON.stringify(toProcess, null, 2)}`
        }]
    })

    spinner.stop("Notes generated")

    const text = response.content.find(b => b.type === "text") as any
    const rawText = text?.text ?? ""

    let suggestions: Array<{ id: string; note: string | null }> = []
    try {
        suggestions = extractJson(rawText)
    } catch {
        console.error("Failed to parse Claude's response:")
        console.log(rawText)
        return
    }

    const toUpdate = suggestions.filter(s => s.note !== null && s.note?.trim())

    if (toUpdate.length === 0) {
        p.outro("No notes to add — all transactions are self-explanatory.")
        return
    }

    console.log(`\nWill add notes to ${toUpdate.length} transaction(s):`)
    const preview = toUpdate.slice(0, 10)
    for (const s of preview) {
        const t = toProcess.find(f => f.id === s.id)
        console.log(`  ${t?.date}  ${t?.payee}: "${s.note}"`)
    }
    if (toUpdate.length > 10) console.log(`  ... and ${toUpdate.length - 10} more`)

    if (dryRun) {
        console.log("\nDry run — no changes applied.")
        p.outro("Done!")
        return
    }

    const confirm = await p.confirm({ message: `Apply ${toUpdate.length} note(s)?` })
    if (p.isCancel(confirm) || !confirm) {
        p.cancel("Cancelled.")
        return
    }

    const applySpinner = p.spinner()
    applySpinner.start("Applying notes...")

    for (const s of toUpdate) {
        await api.updateTransaction(s.id, { notes: s.note })
    }

    await actualApi.sync()
    applySpinner.stop(`Added notes to ${toUpdate.length} transactions`)
    p.outro("Done!")
}

// ─── query ────────────────────────────────────────────────────────────────

async function query(client: Anthropic, config: Config, args: string[]) {
    const since = args.find(a => a.startsWith("--since="))?.split("=")[1]
    const inlineQuestion = args.filter(a => !a.startsWith("--")).join(" ").trim()

    const question = inlineQuestion || (await p.text({
        message: "What do you want to know about your transactions?",
        placeholder: "e.g. How much did I spend on groceries last month?",
        validate: v => v?.trim() ? undefined : "Please enter a question",
    }) as string)

    if (p.isCancel(question)) {
        p.cancel("Cancelled.")
        return
    }

    const spinner = p.spinner()
    spinner.start("Loading transactions...")

    const transactions = await loadTransactions(config, since)
    const { formatted } = await resolveNames(transactions)

    spinner.stop(`Loaded ${formatted.length} transactions`)

    if (formatted.length === 0) {
        p.outro("No transactions found.")
        return
    }

    const txnText = formatted
        .map(t => `${t.date} | ${Number(t.amount) >= 0 ? "+" : ""}${t.amount} NOK | ${t.payee} | ${t.category}${t.notes ? ` | ${t.notes}` : ""}`)
        .join("\n")

    console.log("")

    const stream = client.messages.stream({
        model: "claude-haiku-4-5",
        max_tokens: 4096,
        system: "You are a personal finance assistant with access to the user's transaction data. Answer questions clearly and concisely. Use NOK currency. Use markdown where helpful.",
        messages: [{
            role: "user",
            content: `My transactions${since ? ` since ${since}` : ` (last 90 days)`}:\n\n${txnText}\n\n${question}`,
        }]
    })

    for await (const event of stream) {
        if (event.type === "content_block_delta" && event.delta.type === "text_delta") {
            process.stdout.write(event.delta.text)
        }
    }

    console.log("\n")
    p.outro("Done!")
}