"""Go code generator."""

import json
from curlconverter.parser import ParsedCurl
from curlconverter.generators import register_generator


def _detect_content_type(headers: dict, data: str) -> str:
    """Detect content type from headers or data."""
    if "Content-Type" in headers:
        return headers["Content-Type"]
    if "content-type" in headers:
        return headers["content-type"]
    if data:
        try:
            json.loads(data)
            return "application/json"
        except (json.JSONDecodeError, TypeError):
            pass
    return "application/x-www-form-urlencoded"


@register_generator("go")
def generate_go(parsed: ParsedCurl) -> str:
    """Generate Go net/http code from parsed curl data."""
    lines = []
    lines.append("package main")
    lines.append("")
    lines.append('import (')
    lines.append('    "bytes"')
    lines.append('    "fmt"')
    lines.append('    "net/http"')
    lines.append('    "io/ioutil"')
    lines.append(")")
    lines.append("")
    
    lines.append("func main() {")
    lines.append(f'    url := "{parsed.url}"')
    lines.append("")
    
    headers = dict(parsed.headers) if parsed.headers else {}
    
    if parsed.user_agent and "User-Agent" not in headers and "user-agent" not in headers:
        headers["User-Agent"] = parsed.user_agent
    
    if headers:
        lines.append("    headers := map[string]string{")
        for k, v in headers.items():
            lines.append(f'        "{k}": "{v}",')
        lines.append("    }")
        lines.append("")
    
    body_var = ""
    if parsed.data:
        content_type = _detect_content_type(headers, parsed.data)
        
        if content_type == "application/json":
            try:
                json_data = json.loads(parsed.data)
                json_str = json.dumps(json_data)
                lines.append(f'    jsonData := `{json_str}`')
                body_var = "bytes.NewBuffer([]byte(jsonData))"
            except (json.JSONDecodeError, TypeError):
                escaped = parsed.data.replace("`", "\\`").replace("${", "\\$ {")
                lines.append(f'    data := `{escaped}`')
                body_var = "bytes.NewBuffer([]byte(data))"
        else:
            escaped = parsed.data.replace("`", "\\`").replace("${", "\\$ {")
            lines.append(f'    data := `{escaped}`')
            body_var = "bytes.NewBuffer([]byte(data))"
        
        if "Content-Type" not in headers and "content-type" not in headers:
            headers["Content-Type"] = content_type
        
        lines.append("")
    
    lines.append(f'    req, err := http.NewRequest("{parsed.method}", url, {body_var or "nil"})')
    lines.append("    if err != nil {")
    lines.append("        panic(err)")
    lines.append("    }")
    lines.append("")
    
    if headers:
        lines.append("    for key, value := range headers {")
        lines.append("        req.Header.Add(key, value)")
        lines.append("    }")
        lines.append("")
    
    if parsed.auth:
        lines.append(f'    req.SetBasicAuth("{parsed.auth[0]}", "{parsed.auth[1]}")')
        lines.append("")
    
    if parsed.cookies:
        lines.append(f'    req.Header.Add("Cookie", "{parsed.cookies}")')
        lines.append("")
    
    lines.append("    client := &http.Client{}")
    lines.append("    resp, err := client.Do(req)")
    lines.append("    if err != nil {")
    lines.append("        panic(err)")
    lines.append("    }")
    lines.append("    defer resp.Body.Close()")
    lines.append("")
    lines.append("    body, _ := ioutil.ReadAll(resp.Body)")
    lines.append("    fmt.Println(string(body))")
    lines.append("}")
    
    return "\n".join(lines)