import net.urllib
import os
import readline

const vroot = @VMODROOT

// get output from `v doctor`
fn get_vdoctor_output(is_verbose bool) string {
    vexe := os.getenv('VEXE')
    verbose_flag := if is_verbose { '-v' } else { '' }
    result := os.execute('${os.quoted_path(vexe)} ${verbose_flag} doctor')
    if result.exit_code != 0 {
        eprintln('unable to get `v doctor` output: ${result.output}')
        return ''
    }
    return result.output
}

// get ouput from `v -g -o vdbg cmd/v && vdbg file.v`
fn get_v_build_output(is_verbose bool, is_yes bool, file_path string) string {
    mut vexe := os.getenv('VEXE')
    // prepare a V compiler with -g to have better backtraces if possible
    wd := os.getwd()
    os.chdir(vroot) or {}
    verbose_flag := if is_verbose { '-v' } else { '' }
    vdbg_path := $if windows { '${vroot}/vdbg.exe' } $else { '${vroot}/vdbg' }
    vdbg_compilation_cmd := '${os.quoted_path(vexe)} ${verbose_flag} -g -o ${os.quoted_path(vdbg_path)} cmd/v'
    vdbg_result := os.execute(vdbg_compilation_cmd)
    os.chdir(wd) or {}
    if vdbg_result.exit_code == 0 {
        vexe = vdbg_path
    } else {
        eprintln('unable to compile V in debug mode: ${vdbg_result.output}\ncommand: ${vdbg_compilation_cmd}\n')
    }
    //
    mut result := os.execute('${os.quoted_path(vexe)} ${verbose_flag} ${os.quoted_path(file_path)}')
    defer {
        os.rm(vdbg_path) or {
            if is_verbose {
                eprintln('unable to delete `vdbg`: ${err}')
            }
        }
    }
    if result.exit_code == 0 {
        defer {
            mut generated_file := file_path.all_before_last('.')
            $if windows {
                generated_file += '.exe'
            }
            os.rm(generated_file) or {
                if is_verbose {
                    eprintln('unable to delete generated file: ${err}')
                }
            }
        }
        run := is_yes
            || ask('It looks like the compilation went well, do you want to run the file?')
        if run {
            result = os.execute('${os.quoted_path(vexe)} ${verbose_flag} run ${os.quoted_path(file_path)}')
            if result.exit_code == 0 && !is_yes {
                confirm_or_exit('It looks like the file ran correctly as well, are you sure you want to continue?')
            }
        }
    }
    return result.output
}

fn ask(msg string) bool {
    prompt := os.input_opt('${msg} [Y/n] ') or { 'y' }
    return prompt == '' || prompt[0].ascii_str().to_lower() != 'n'
}

fn confirm_or_exit(msg string) {
    if !ask(msg) {
        exit(1)
    }
}

fn main() {
    mut file_path := ''
    mut is_verbose := false
    mut is_yes := false
    for arg in os.args[2..] {
        match arg {
            '-v' {
                is_verbose = true
            }
            '-y' {
                is_yes = true
            }
            else {
                if !arg.ends_with('.v') && !arg.ends_with('.vsh') && !arg.ends_with('.vv') {
                    eprintln('unknown argument: `${arg}`')
                    exit(1)
                }
                if file_path != '' {
                    eprintln('only one V file can be submitted')
                    exit(1)
                }
                file_path = arg
            }
        }
    }
    if file_path == '' {
        eprintln('v bug: no v file listed to report')
        exit(1)
    }
    os.unsetenv('VCOLORS')
    // collect error information
    // output from `v doctor`
    vdoctor_output := get_vdoctor_output(is_verbose)
    // file content
    file_content := os.read_file(file_path) or {
        eprintln('unable to get file "${file_path}" content: ${err}')
        ''
    }
    // output from `v -g -o vdbg cmd/v && vdbg file.v`
    build_output := get_v_build_output(is_verbose, is_yes, file_path)
    // ask the user if he wants to submit even after an error
    if !is_yes && (vdoctor_output == '' || file_content == '' || build_output == '') {
        confirm_or_exit('An error occurred retrieving the information, do you want to continue?')
    }

    expected_result := readline.read_line('What did you expect to see? ') or {
        // Ctrl-C was pressed
        eprintln('\nCanceled')
        exit(1)
    }
    // open prefilled issue creation page, or print link as a fallback

    if !is_yes && vdoctor_output.contains('behind V master') {
        confirm_or_exit('It looks like your installation of V is outdated, we advise you to run `v up` before submitting an issue. Are you sure you want to continue?')
    }

    // When updating this template, make sure to update `.github/ISSUE_TEMPLATE/bug_report.md` too
    raw_body := '<!-- It is advisable to update all relevant modules using `v outdated` and `v install` -->
**V doctor:**
```
${vdoctor_output}
```

**What did you do?**
`v -g -o vdbg cmd/v && vdbg ${file_path}`
{file_content}

**What did you expect to see?**

${expected_result}

**What did you see instead?**
```
${build_output}```'
    mut encoded_body := urllib.query_escape(raw_body.replace_once('{file_content}', '```v\n${file_content}\n```'))
    mut generated_uri := 'https://github.com/vlang/v/issues/new?labels=Bug&body=${encoded_body}'
    if generated_uri.len > 8192 {
        // GitHub doesn't support URLs longer than 8192 characters
        encoded_body = urllib.query_escape(raw_body.replace_once('{file_content}', 'See attached file `${file_path}`'))
        generated_uri = 'https://github.com/vlang/v/issues/new?labels=Bug&body=${encoded_body}'
        println('Your file is too big to be submitted. Head over to the following URL and attach your file.')
        println(generated_uri)
    } else {
        os.open_uri(generated_uri) or {
            if is_verbose {
                eprintln(err)
            }
            println(generated_uri)
        }
    }
}