#!/usr/bin/env nu
# export-tracking.nu - Export tracking data in multiple formats
# Follows NuShell 0.108+ guidelines with explicit types

def main [
    format: string = "json"       # Required positional
    --output: string = "export"  # Flag with value
    --project: string = ""        # Optional filter
    --status: string = "all"      # Filter by status
    --verbose = false
]: void {
    # Rule 3: Early validation
    if $format not-in ["json", "csv", "kanban", "markdown"] {
        error make {
            msg: $"Invalid format: [$format]. Must be: json, csv, kanban, or markdown"
        }
    }

    if $verbose {
        print "📊 Starting tracking export..."
        print $"📁 Format: [$format]"
        if ($project != "") {
            print $"🎯 Project filter: [$project]"
        }
    }

    # Rule 13: Predictable naming (get-tracking-data)
    let data = get-tracking-data $project $status

    # Rule 17: String interpolation
    let output-file = $"[$output].($format)"

    if $verbose {
        print $"📝 Exporting to [$output-file]"
    }

    # Rule 1: Single purpose - format and save
    match $format {
        "json" => {
            let json-content = ($data | to json)
            $json-content | save --force $output-file
        }
        "csv" => {
            let csv-content = format-csv $data
            $csv-content | save --force $output-file
        }
        "kanban" => {
            let kanban-content = format-kanban $data
            $kanban-content | save --force $output-file
        }
        "markdown" => {
            let md-content = format-markdown $data
            $md-content | save --force $output-file
        }
    }

    print $"✅ Exported to [$output-file]"

    # Rule 17: ($expr) for expressions
    let file-size = (stat $output-file | get size)
    print $"📦 File size: (($file-size / 1024) | math round --precision 2) KB"
}

# Rule 1: Single purpose - fetches data
def get-tracking-data [project-filter: string, status-filter: string]: table {
    let url = if ($project-filter == "") {
        # Rule 17: Expression interpolation
        $"http://localhost:3000/api/v1/tracking/summary?status=($status-filter)"
    } else {
        $"http://localhost:3000/api/v1/tracking/projects/($project-filter)?status=($status-filter)"
    }

    try {
        http get $url | get items
    } catch {
        print "⚠️  Could not fetch data from tracking API"
        print "   Make sure tracking server is running: cargo run -p vapora-backend"
        []
    }
}

# Rule 1: Single purpose - formats as CSV
def format-csv [data: table]: string {
    let header = "id,project,source,type,summary,timestamp\n"

    let rows = (
        $data
        | each { |item|
            $"($item.id),($item.project_path),($item.source),($item.entry_type),\"($item.summary)\",($item.timestamp)"
        }
        | str join "\n"
    )

    $header + $rows
}

# Rule 1: Single purpose - formats as Kanban
def format-kanban [data: table]: string {
    let pending = ($data | where entry_type =~ "Todo" | where status == "Pending")
    let in-progress = ($data | where entry_type =~ "Todo" | where status == "InProgress")
    let completed = ($data | where entry_type =~ "Todo" | where status == "Completed")

    let output = $"
# Kanban Board

## 📋 Pending ($($pending | length) items)

($pending | each { |item|
    $"- [$item.summary] *($item.priority)*"
} | str join "\n")

## 🔄 In Progress ($($in-progress | length) items)

($in-progress | each { |item|
    $"- [$item.summary] *($item.priority)*"
} | str join "\n")

## ✅ Completed ($($completed | length) items)

($completed | each { |item|
    $"- ✅ [$item.summary]"
} | str join "\n")
"

    $output
}

# Rule 1: Single purpose - formats as Markdown
def format-markdown [data: table]: string {
    let changes = ($data | where source =~ "Change")
    let todos = ($data | where source =~ "Todo")

    let output = $"
# Tracking Report

Generated: (date now | format date '%Y-%m-%d %H:%M:%S UTC')

## Summary

- **Total Entries**: ($($data | length))
- **Changes**: ($($changes | length))
- **TODOs**: ($($todos | length))

## Changes

($changes | each { |item|
    $"### [$item.timestamp] - ($item.summary)

**Impact**: ($item.impact) | **Breaking**: ($item.breaking)

"
} | str join)

## TODOs

($todos | each { |item|
    $"### [$item.summary]

**Priority**: ($item.priority) | **Estimate**: ($item.estimate) | **Status**: ($item.status)

"
} | str join)
"

    $output
}