import { FastifyInstance } from "fastify"
import {
    eq,
    ilike,
    asc,
    desc,
    and,
    count,
    inArray,
    or
} from "drizzle-orm"

import {
    contracts,
    customers,
    files
} from "../../../db/schema"

// -------------------------------------------------------------
// Helper: SQL‐LIKE Suche über mehrere Felder
// -------------------------------------------------------------
function buildSearchCondition(table: any, columns: string[], search?: string) {
    if (!search) return null

    const term = `%${search.toLowerCase()}%`

    const conditions = columns
        .map(col => table[col])
        .filter(Boolean)
        .map(col => ilike(col, term))

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

    // @ts-ignore
    return or(...conditions)
}

export default async function contractsRoutes(server: FastifyInstance) {

    // -------------------------------------------------------------
    // LIST
    // -------------------------------------------------------------
    server.get("/resource/contracts", async (req, reply) => {
        const tenantId = req.user?.tenant_id
        if (!tenantId) return reply.code(400).send({ error: "No tenant selected" })

        const { search, sort, asc: ascQuery } = req.query as {
            search?: string
            sort?: string
            asc?: string
        }

        let whereCond: any = eq(contracts.tenant, tenantId)

        // SQL SEARCH
        const searchCond = buildSearchCondition(
            contracts,
            ["name", "notes", "contractNumber", "paymentType", "sepaRef", "bankingName"],
            search
        )
        if (searchCond) whereCond = and(whereCond, searchCond)

        // Query
        let q = server.db
            .select()
            .from(contracts)
            .where(whereCond)

        // SORT
        if (sort) {
            const field = (contracts as any)[sort]
            if (field) {
                //@ts-ignore
                q = q.orderBy(
                    ascQuery === "true" ? asc(field) : desc(field)
                )
            }
        }

        return await q
    })


    // -------------------------------------------------------------
    // PAGINATED
    // -------------------------------------------------------------
    server.get("/resource/contracts/paginated", async (req, reply) => {
        try {
            const tenantId = req.user?.tenant_id
            if (!tenantId) return reply.code(400).send({ error: "No tenant selected" })

            const queryConfig = req.queryConfig
            const { pagination, sort, filters, paginationDisabled } = queryConfig

            const { search, distinctColumns } = req.query as {
                search?: string
                distinctColumns?: string
            }

            // -----------------------------------
            // WHERE
            // -----------------------------------
            let whereCond: any = eq(contracts.tenant, tenantId)

            if (filters) {
                for (const [key, val] of Object.entries(filters)) {
                    const col = (contracts as any)[key]
                    if (!col) continue

                    if (Array.isArray(val)) {
                        whereCond = and(whereCond, inArray(col, val))
                    } else {
                        whereCond = and(whereCond, eq(col, val as any))
                    }
                }
            }

            // SQL SEARCH
            const searchCond = buildSearchCondition(
                contracts,
                ["name", "notes", "contractNumber", "paymentType", "sepaRef", "bankingName"],
                search
            )
            if (searchCond) whereCond = and(whereCond, searchCond)

            // -----------------------------------
            // COUNT
            // -----------------------------------
            const totalRes = await server.db
                .select({ value: count(contracts.id) })
                .from(contracts)
                .where(whereCond)

            const total = Number(totalRes[0]?.value ?? 0)

            // -----------------------------------
            // DISTINCT
            // -----------------------------------
            const distinctValues: Record<string, any[]> = {}

            if (distinctColumns) {
                for (const colName of distinctColumns.split(",")) {
                    const col = (contracts as any)[colName.trim()]
                    if (!col) continue

                    const rows = await server.db
                        .select({ v: col })
                        .from(contracts)
                        .where(eq(contracts.tenant, tenantId))

                    distinctValues[colName] =
                        [...new Set(rows.map(r => r.v).filter(v => v != null && v !== ""))]
                            .sort()
                }
            }

            // -----------------------------------
            // PAGINATION
            // -----------------------------------
            let offset = pagination?.offset ?? 0
            let limit = pagination?.limit ?? 999999

            // -----------------------------------
            // SORT
            // -----------------------------------
            let orderField = null
            let orderDir: "asc" | "desc" = "asc"

            if (sort?.length > 0) {
                const s = sort[0]
                const col = (contracts as any)[s.field]
                if (col) {
                    orderField = col
                    orderDir = s.direction === "asc" ? "asc" : "desc"
                }
            }

            // -----------------------------------
            // QUERY DATA
            // -----------------------------------
            let q = server.db
                .select()
                .from(contracts)
                .where(whereCond)
                .offset(offset)
                .limit(limit)

            if (orderField) {
                //@ts-ignore
                q = orderDir === "asc" ? q.orderBy(asc(orderField)) : q.orderBy(desc(orderField))
            }

            const data = await q

            return {
                data,
                queryConfig: {
                    ...queryConfig,
                    total,
                    totalPages: pagination?.limit ? Math.ceil(total / pagination.limit) : 1,
                    distinctValues,
                    search: search || null,
                }
            }
        } catch (e) {
            console.error(e)
            return reply.code(500).send({ error: "Internal Server Error" })
        }
    })


    // -------------------------------------------------------------
    // DETAIL (+ JOINS)
    // -------------------------------------------------------------
    server.get("/resource/contracts/:id", async (req, reply) => {
        const { id } = req.params as { id: string }
        const tenantId = req.user?.tenant_id

        if (!tenantId) return reply.code(400).send({ error: "No tenant selected" })

        const rows = await server.db
            .select()
            .from(contracts)
            .where(and(eq(contracts.id, Number(id)), eq(contracts.tenant, tenantId)))
            .limit(1)

        if (!rows.length) return reply.code(404).send({ error: "Not found" })

        const contract = rows[0]

        const [customerRecord, fileList] = await Promise.all([
            contract.customer
                ? server.db.select().from(customers).where(eq(customers.id, contract.customer))
                : [],
            server.db.select().from(files).where(eq(files.contract, Number(id))),
        ])

        return {
            ...contract,
            customer: customerRecord[0] ?? null,
            files: fileList,
        }
    })
}