import { mkdtempSync, rmSync, writeFileSync } from 'node:fs'
import { tmpdir } from 'node:os'
import { join } from 'node:path'
import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
import {
    ConnectionNotFoundError,
    configHash,
    createRegistry,
    RegistryError
} from '../../../src/config/registry.js'
import { writeStore } from '../../../src/config/store.js'
import type { ConnectionConfig } from '../../../src/config/types.js'

const conn = (name: string, extra: Partial<ConnectionConfig> = {}): ConnectionConfig => ({
    name,
    type: 'postgres',
    host: 'localhost',
    user: 'postgres',
    readonly: false,
    ...extra
})

describe('registry', () => {
    let dir: string
    let storePath: string
    let configPath: string

    beforeEach(() => {
        dir = mkdtempSync(join(tmpdir(), 'dbmole-registry-'))
        storePath = join(dir, 'connections.json')
        configPath = join(dir, 'config.json')
        vi.spyOn(console, 'error').mockImplementation(() => {})
    })

    afterEach(() => {
        rmSync(dir, { recursive: true, force: true })
        vi.restoreAllMocks()
    })

    it('merges layers with env > config > store priority', () => {
        writeStore(storePath, [conn('a', { host: 'from-store' }), conn('s')])
        writeFileSync(
            configPath,
            JSON.stringify({ connections: [conn('a', { host: 'from-config' }), conn('c')] })
        )
        const env = { DBMOLE_CONNECTIONS: JSON.stringify([conn('a', { host: 'from-env' })]) }
        const registry = createRegistry({ storePath, configPath, env })

        const list = registry.list()
        expect(list.map((r) => r.config.name)).toEqual(['a', 'c', 's'])
        expect(registry.resolve('a').config.host).toBe('from-env')
        expect(registry.resolve('a').source).toBe('env')
        expect(registry.resolve('c').source).toBe('config')
        expect(registry.resolve('s').source).toBe('store')
    })

    it('resolve throws with available names listed', () => {
        writeStore(storePath, [conn('only')])
        const registry = createRegistry({ storePath, env: {} })
        expect(() => registry.resolve('nope')).toThrow(ConnectionNotFoundError)
        expect(() => registry.resolve('nope')).toThrow(/only/)
    })

    it('sees external store edits without recreation (hot reload)', () => {
        const registry = createRegistry({ storePath, env: {} })
        expect(registry.list()).toEqual([])
        writeStore(storePath, [conn('late')])
        expect(registry.resolve('late').config.name).toBe('late')
    })

    it('add writes to store and rejects duplicates from any layer', () => {
        const env = { DBMOLE_CONNECTIONS: JSON.stringify([conn('envy')]) }
        const registry = createRegistry({ storePath, env })
        const added = registry.add(conn('fresh'))
        expect(added.source).toBe('store')
        expect(registry.resolve('fresh').source).toBe('store')
        expect(() => registry.add(conn('fresh'))).toThrow(RegistryError)
        expect(() => registry.add(conn('envy'))).toThrow(/env/)
    })

    it('update patches fields, removes them via null, and revalidates', () => {
        writeStore(storePath, [conn('u', { database: 'old', port: 5433 })])
        const registry = createRegistry({ storePath, env: {} })
        const updated = registry.update('u', { database: 'new', port: null, readonly: true })
        expect(updated.config.database).toBe('new')
        expect(updated.config.port).toBeUndefined()
        expect(updated.config.readonly).toBe(true)
        expect(registry.resolve('u').config.database).toBe('new')
        expect(() => registry.update('u', { host: '' })).toThrow()
    })

    it('update can rename unless the new name is taken', () => {
        writeStore(storePath, [conn('old-name'), conn('taken')])
        const registry = createRegistry({ storePath, env: {} })
        registry.update('old-name', { name: 'new-name' })
        expect(registry.resolve('new-name').config.name).toBe('new-name')
        expect(() => registry.resolve('old-name')).toThrow(ConnectionNotFoundError)
        expect(() => registry.update('new-name', { name: 'taken' })).toThrow(RegistryError)
    })

    it('update and remove refuse non-store connections', () => {
        const env = { DBMOLE_CONNECTIONS: JSON.stringify([conn('envy')]) }
        const registry = createRegistry({ storePath, env })
        expect(() => registry.update('envy', { host: 'x' })).toThrow(/env/)
        expect(() => registry.remove('envy')).toThrow(/env/)
    })

    it('remove deletes from store', () => {
        writeStore(storePath, [conn('gone'), conn('stays')])
        const registry = createRegistry({ storePath, env: {} })
        registry.remove('gone')
        expect(() => registry.resolve('gone')).toThrow(ConnectionNotFoundError)
        expect(registry.resolve('stays').config.name).toBe('stays')
    })

    it('update and remove of unknown names throw not-found', () => {
        const registry = createRegistry({ storePath, env: {} })
        expect(() => registry.update('ghost', {})).toThrow(ConnectionNotFoundError)
        expect(() => registry.remove('ghost')).toThrow(ConnectionNotFoundError)
    })
})

describe('configHash', () => {
    it('is stable across key order', () => {
        const a = conn('h', { port: 1, database: 'd' })
        const b = { database: 'd', port: 1, ...conn('h') } as ConnectionConfig
        expect(configHash(a)).toBe(configHash(b))
    })

    it('changes when a value changes', () => {
        expect(configHash(conn('h'))).not.toBe(configHash(conn('h', { port: 9 })))
    })
})