import { getAppBaseUrl } from './common.ts'

// ============================================================================
// Types
// ============================================================================

/** Tabs on a canvas. These are real routes, so they can be linked directly. */
export type CanvasTab = 'craft' | 'test' | 'usage' | 'workstation'

/** Tabs on a workflow. Also real routes. */
export type WorkflowTab = 'craft' | 'test' | 'usage'

export interface WorkflowUrlOptions {
    tab?: WorkflowTab
    /** Pin the page to one version instead of the latest. */
    promptVersionId?: string
    /** Open a specific run. */
    executionId?: string
    /** Select a specific node — the link to send when one step is misbehaving. */
    nodeId?: string
}

export interface TelaLink {
    /** What the user gets by opening it, in their terms. */
    label: string
    url: string
}

// ============================================================================
// Entity links
// ============================================================================

function withQuery(url: string, params: Record<string, string | undefined>): string {
    const query = new URLSearchParams()

    for (const [key, value] of Object.entries(params)) {
        if (value)
            query.set(key, value)
    }

    const search = query.toString()
    return search ? `${url}?${search}` : url
}

/**
 * A canvas, on the tab that matches what the user is doing.
 *
 * Canvas tabs are routes, so `test` and `workstation` are directly linkable. There is no
 * per-test-case or per-version query parameter on this route — the tab is as deep as it goes.
 */
export function getCanvasTabUrl(canvasId: string, tab: CanvasTab = 'craft'): string {
    return `${getAppBaseUrl()}/prompt/${canvasId}/${tab}`
}

/**
 * A workflow, optionally pinned to a version, a run, or a single node.
 *
 * `nodeId` is the one to reach for when a specific step is the problem: it opens the editor with
 * that node selected, which is the difference between "here is your workflow" and "here is the
 * step that failed".
 */
export function getWorkflowTabUrl(promptId: string, options: WorkflowUrlOptions = {}): string {
    const base = `${getAppBaseUrl()}/workflows/${promptId}${options.tab ? `/${options.tab}` : ''}`

    return withQuery(base, {
        promptVersionId: options.promptVersionId,
        executionId: options.executionId,
        nodeId: options.nodeId,
    })
}

/**
 * An agent. `branch` is the only deep-link parameter it accepts.
 *
 * The agent's craft/test/usage tabs are component state rather than routes, so unlike a canvas or a
 * workflow they cannot be linked to directly — say "open the Test tab" alongside the link.
 */
export function getAgentPageUrl(agentId: string, options: { branch?: string } = {}): string {
    return withQuery(`${getAppBaseUrl()}/agent/${agentId}`, { branch: options.branch })
}

/** One agent run, with its full session transcript. */
export function getAgentSessionUrl(sessionId: string): string {
    return `${getAppBaseUrl()}/agent/run/${sessionId}`
}

/** The template gallery. */
export function getTemplatesUrl(): string {
    return `${getAppBaseUrl()}/templates`
}

// ============================================================================
// "See and debug it here"
// ============================================================================

/**
 * The links worth handing a user for a canvas, given what they were doing.
 *
 * Always includes the craft view; adds the test view once test cases exist and the Workstation
 * once an application does.
 */
export function getCanvasLinks(
    canvasId: string,
    options: { hasTestCases?: boolean, hasWorkstation?: boolean } = {},
): TelaLink[] {
    const links: TelaLink[] = [
        { label: 'edit the prompt', url: getCanvasTabUrl(canvasId, 'craft') },
    ]

    if (options.hasTestCases)
        links.push({ label: 'run and review test cases', url: getCanvasTabUrl(canvasId, 'test') })

    if (options.hasWorkstation)
        links.push({ label: 'run it as tasks', url: getCanvasTabUrl(canvasId, 'workstation') })

    return links
}

/**
 * The links worth handing a user for a workflow. Pass what you know: a failing node or a specific
 * run turns a generic link into one that lands on the problem.
 */
export function getWorkflowLinks(
    promptId: string,
    options: { promptVersionId?: string, executionId?: string, nodeId?: string, hasTestCases?: boolean } = {},
): TelaLink[] {
    const { promptVersionId, executionId, nodeId } = options

    const links: TelaLink[] = [
        {
            label: nodeId ? 'open the workflow with that step selected' : 'edit the workflow',
            url: getWorkflowTabUrl(promptId, { tab: 'craft', promptVersionId, nodeId }),
        },
    ]

    if (executionId) {
        links.push({
            label: 'inspect that run',
            url: getWorkflowTabUrl(promptId, { tab: 'test', promptVersionId, executionId }),
        })
    }
    else if (options.hasTestCases) {
        links.push({
            label: 'run and review test cases',
            url: getWorkflowTabUrl(promptId, { tab: 'test', promptVersionId }),
        })
    }

    return links
}

/**
 * The links worth handing a user for an agent.
 */
export function getAgentLinks(
    agentId: string,
    options: { sessionId?: string, branch?: string } = {},
): TelaLink[] {
    const links: TelaLink[] = [
        { label: 'edit the agent', url: getAgentPageUrl(agentId, { branch: options.branch }) },
    ]

    if (options.sessionId)
        links.push({ label: 'read that run', url: getAgentSessionUrl(options.sessionId) })

    return links
}

/**
 * Render links as the closing line of an answer.
 *
 * ```
 * formatLinks([{ label: 'edit the prompt', url: '…' }])
 * // → 'You can see and debug it here: edit the prompt — https://…'
 * ```
 */
export function formatLinks(links: TelaLink[], lead = 'You can see and debug it here'): string {
    if (!links.length)
        return ''

    if (links.length === 1)
        return `${lead}: ${links[0]!.url}`

    return [`${lead}:`, ...links.map(link => `- ${link.label}: ${link.url}`)].join('\n')
}